real relative imports

.gitignore

@@ -2,3 +2,5 @@
 /out*
 /TODO
 /vscode
+/fuzz
+/perf.data*

README.md

@@ -4,14 +4,15 @@ A very cool language
 
 ## Features
 * Clean indentation-based syntax
-* Compiles to x86_64 Assembly
+* Compiles to x86-64 Assembly
 * No libc required!
 * Produces tiny static executables (11KB for `hello.zr`)
-* Has type inference, [UFCS](https://en.wikipedia.org/wiki/Uniform_function_call_syntax), variadics, dynamic arrays, hashmaps, DNS resolver, etc.
-* Growing [standard library](https://git.ton1.dev/toni/zern/src/branch/main/src/std)
+* Has static typing, [UFCS](https://en.wikipedia.org/wiki/Uniform_function_call_syntax), variadics, dynamic arrays, hashmaps, DNS resolver, etc.
 
 ## Syntax
 ```rust
+include "$/io.zr"
+
 func main[] : i64
     answer := os.urandom_i64()->abs() % 100
 

examples/brainfuck.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     // https://brainfuck.org/sierpinski.b
     src := "++++++++[>+>++++<<-]>++>>+<[-[>>+<<-]+>>]>+[-<<<[->[+[-]+>++>>>-<<]<[<]>>++++++[<<+++++>>-]+<<++.[-]<<]>.>+[>>]>+]"

examples/chip8.zr

@@ -1,4 +1,7 @@
 // needs to be compiled with -m -C "-lraylib"
+include "$/io.zr"
+include "$/os.zr"
+
 extern InitWindow
 extern SetTargetFPS
 extern WindowShouldClose
@@ -49,7 +52,7 @@ func CHIP8.free[c: CHIP8] : void
     c->keyboard->free()
     c->display->free()
     c->keyboard_map->free()
-    mem.free(c)
+    (c as ptr)->free()
 
 func CHIP8.disassemble[c: CHIP8, ins_count: i64] : void
     for i in 0..ins_count
@@ -275,7 +278,7 @@ func main[argc: i64, argv: ptr] : i64
     disassemble := false
 
     for i in 1..argc
-        arg := mem.read64(argv + i * 8) as str
+        arg := os.arg(argv, i)
         if arg->equal("-d")
             disassemble = true
         else
@@ -288,7 +291,7 @@ func main[argc: i64, argv: ptr] : i64
     c := new CHIP8
     c->init()
 
-    ~buffer, ok := io.read_binary_file(path)
+    buffer, ok := io.read_binary_file(path)
     if !ok
         panic("failed to read file")
 

examples/curl.zr

@@ -1,15 +1,18 @@
+include "$/io.zr"
+include "$/net.zr"
+
 func main[argc: i64, argv: ptr] : i64
     if argc < 2
         io.println("ERROR: url is missing")
         return 1
 
-    url := mem.read64(argv + 8) as str
+    url := os.arg(argv, 1)
 
     if url->len() <= 7
         io.println("ERROR: invalid url (Did you forget \"http://\"?)")
         return 1
 
-    if !url->substr(0, 7)->equal("http://")
+    if !url->substr_n(0, 7)->equal("http://")
         io.println("ERROR: only http scheme is supported")
         return 1
     
@@ -21,23 +24,19 @@ func main[argc: i64, argv: ptr] : i64
             break
         i += 1
 
-    host := url->substr(host_start, i - host_start)
+    host := url->substr_n(host_start, i - host_start)
     path := "/"
     if i < url_len
-        path = url->substr(i, url_len - i)
+        path = url->substr_n(i, url_len - i)
     
-    ~s, ok := net.connect(host, 80)
+    s, ok := net.connect(host, 80)
     if !ok
         panic("failed to connect")
 
-    req := new str.Builder
-    req->append("GET ")
-    req->append(path)
-    req->append(" HTTP/1.0\r\nHost: ")
-    req->append(host)
-    req->append("\r\nConnection: close\r\n\r\n")
-    net.send(s, req->data, req->size)
-    req->destroy()
+    // seems reasonable
+    req := _stackalloc(4096) as str
+    req_size := req->format_into(4096, "GET %s HTTP/1.0\r\nHost: %s\r\nConnection: close\r\n\r\n", path, host)
+    net.send(s, req as ptr, req_size)
 
     header_buf := mem.alloc(8192) as str
     header_size := 0

examples/euler/euler_00.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     sum := 0
 

examples/euler/euler_01.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     sum := 0
 

examples/euler/euler_02.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     sum := 0
     a := 0

examples/euler/euler_03.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     n := 600851475143
     f := 2

examples/euler/euler_04.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     out := 0
 

examples/euler/euler_05.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     out := 1
 

examples/euler/euler_06.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     sum_of_squares := 0
     for i in 1..101

examples/euler/euler_07.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     found := 0
 

examples/euler/euler_08.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     n := "7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450"
 

examples/euler/euler_09.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     for a in 1..1000
         for b in 1..1000

examples/euler/euler_10.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     sum := 0
 

examples/euler/euler_11.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/containers.zr"
+
 func main[] : i64
     N := 20
 

examples/euler/euler_12.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func num_divisors[n: i64] : i64
     end := n->isqrt()
 

examples/euler/euler_13.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     n := 37107287533 + 46376937677 + 74324986199 + 91942213363 + 23067588207 + 89261670696 + 28112879812 + 44274228917 + 47451445736 + 70386486105 + 62176457141 + 64906352462 + 92575867718 + 58203565325 + 80181199384 + 35398664372 + 86515506006 + 71693888707 + 54370070576 + 53282654108 + 36123272525 + 45876576172 + 17423706905 + 81142660418 + 51934325451 + 62467221648 + 15732444386 + 55037687525 + 18336384825 + 80386287592 + 78182833757 + 16726320100 + 48403098129 + 87086987551 + 59959406895 + 69793950679 + 41052684708 + 65378607361 + 35829035317 + 94953759765 + 88902802571 + 25267680276 + 36270218540 + 24074486908 + 91430288197 + 34413065578 + 23053081172 + 11487696932 + 63783299490 + 67720186971 + 95548255300 + 76085327132 + 37774242535 + 23701913275 + 29798860272 + 18495701454 + 38298203783 + 34829543829 + 40957953066 + 29746152185 + 41698116222 + 62467957194 + 23189706772 + 86188088225 + 11306739708 + 82959174767 + 97623331044 + 42846280183 + 55121603546 + 32238195734 + 75506164965 + 62177842752 + 32924185707 + 99518671430 + 73267460800 + 76841822524 + 97142617910 + 87783646182 + 10848802521 + 71329612474 + 62184073572 + 66627891981 + 60661826293 + 85786944089 + 66024396409 + 64913982680 + 16730939319 + 94809377245 + 78639167021 + 15368713711 + 40789923115 + 44889911501 + 41503128880 + 81234880673 + 82616570773 + 22918802058 + 77158542502 + 72107838435 + 20849603980 + 53503534226
-    io.println(n->to_str()->substr(0, 10))
+    io.println(n->to_str()->substr_n(0, 10))

examples/euler/euler_14.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func collatz_num[n: i64] : i64
     if n % 2 == 0
         return n / 2

examples/euler/euler_15.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     n := 40
     r := 20

examples/euler/euler_16.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/containers.zr"
+
 func main[] : i64
     n := [1]
 

examples/euler/euler_17.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/containers.zr"
+
 func main[] : i64
     s1 := [0, 3, 3, 5, 4, 4, 3, 5, 5, 4]
     s2 := [3, 6, 6, 8, 8, 7, 7, 9, 8, 8]

examples/euler/euler_18.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/containers.zr"
+
 func findmax[triangle: Array, row: i64, col: i64] : i64
     if row == 14
         return (triangle->nth(row) as Array)->nth(col)

examples/euler/euler_19.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func days[y: i64, m: i64] : i64
     if m == 2
         if (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0))

examples/euler/euler_20.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/containers.zr"
+
 func multiply[n: Array, x: i64] : void
     carry := 0
     for i in 0..n->size

examples/euler/euler_21.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func divisors_sum[n: i64] : i64
     k := n
     sum := 1

examples/fib.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     a := 0
     b := 1

examples/fizzbuzz.zr

@@ -1,3 +1,5 @@
+include "$/io.zr"
+
 func main[] : i64
     for i in 1..40
         if i % 15 == 0

examples/guess_number.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/os.zr"
+
 func main[] : i64
     answer := os.urandom_i64()->abs() % 100
 

examples/hello.zr

@@ -1,2 +0,0 @@
-func main[] : i64
-    io.println("Hello, World!")

examples/quicksort.zr

@@ -1,15 +0,0 @@
-func main[] : i64
-    arr := []
-    for i in 0..10
-        arr->push(os.urandom_i64()->abs() % 1000)
-
-    for i in 0..arr->size
-        io.println_i64(arr->nth(i))
-    io.println("------------")
-
-    arr->quicksort()
-
-    for i in 0..arr->size
-        io.println_i64(arr->nth(i))
-
-    arr->free()

examples/raylib.zr

@@ -1,4 +1,6 @@
 // needs to be compiled with -m -C "-lraylib"
+include "$/io.zr"
+
 extern InitWindow
 extern SetTargetFPS
 extern WindowShouldClose

examples/rule110.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/containers.zr"
+
 func rule110_step[state: Array] : void
     new_state := []
 

examples/serve.zr

@@ -0,0 +1,96 @@
+// needs to be compiled with -m -C "-lpthread"
+include "$/net.zr"
+
+extern pthread_create
+extern pthread_detach
+
+struct ConnData
+    sock: i64
+    addr: str
+
+func handle_connection[conn: ConnData] : void
+    req := _stackalloc(10001) as str
+    n := net.read(conn->sock, req as ptr, 10000)
+    if n <= 0
+        net.close(conn->sock)
+        conn->addr->free()
+        (conn as ptr)->free()
+        return
+
+    req[n] = 0
+
+    pos := req->find("\r\n")
+    if pos == -1
+        panic("TODO: bad request")
+
+    first_line := req->substr_n(0, pos)
+    parts := first_line->split(" ")
+    method := parts->nth(0) as str
+    path := parts->nth(1) as str
+
+    if !method->equal("GET")
+        // TODO: method not supported
+        return
+    
+    if path->equal("/")
+        // TODO: index
+        return
+    
+    // TODO: ANY validation
+    file_path := "."->concat(path)
+
+    file_size, ok := os.get_file_size(file_path)
+    if !ok
+        // TODO: not found
+        return
+
+    fd := _builtin_syscall(SYS_openat, AT_FDCWD, file_path, O_RDONLY, 0)
+    if fd < 0
+        // TODO: not found
+        return
+    
+    resp := "HTTP/1.1 200 OK\r\nConnection: close\r\n\r\n"
+    net.send(conn->sock, resp as ptr, resp->len())
+    
+    offset := 0
+    while offset < file_size
+        sent := _builtin_syscall(SYS_sendfile, conn->sock, fd, ^offset, IP_MAXPACKET)
+        if sent <= 0
+            break
+
+    net.close(conn->sock)
+
+    _builtin_syscall(SYS_close, fd)
+    file_path->free()
+    first_line->free()
+    parts->free_with_items()
+    conn->addr->free()
+    (conn as ptr)->free()
+
+func main[argc: i64, argv: ptr] : i64
+    port := 8000
+
+    if argc > 1
+        port = os.arg(argv, 1)->parse_i64()
+
+    server_sock, ok := net.listen("0.0.0.0", port)
+    if !ok
+        panic("failed to listen")
+
+    io.printf("Listening on :%d...\n", port)
+
+    addr := _stackalloc(16)
+    while true
+        conn := net.accept(server_sock, addr)
+        if conn < 0
+            io.println("ERROR: failed to accept connection")
+            continue
+
+        conn_data := new* ConnData
+        conn_data->sock = conn
+        conn_data->addr = mem.alloc(30) as str
+        conn_data->addr->format_into(30, "%d.%d.%d.%d:%d", addr[4], addr[5], addr[6], addr[7], mem.read16be(addr + 2))
+
+        thread := 0
+        pthread_create(^thread, 0, ^handle_connection, conn_data)
+        pthread_detach(thread)

examples/sqlite_todo.zr

@@ -1,4 +1,6 @@
 // needs to be compiled with -m -C "-lsqlite3"
+include "$/io.zr"
+
 extern sqlite3_open
 extern sqlite3_exec
 extern sqlite3_prepare_v2

examples/tcp_server.zr

@@ -1,23 +0,0 @@
-func main[] : i64
-    ~s, ok := net.listen("127.0.0.1", 8000)
-    if !ok
-        panic("failed to listen")
-
-    io.println("Listening on port 8000...")
-
-    resp := mem.alloc(IP_MAXPACKET)
-    addr := _stackalloc(16)
-    while true
-        conn := net.accept(s, addr)
-        if conn < 0
-            continue
-
-        io.printf("%d.%d.%d.%d:%d\n", addr[4], addr[5], addr[6], addr[7], mem.read16be(addr + 2))
-
-        n := net.read(conn, resp, IP_MAXPACKET)
-        
-        io.print_sized(resp, n)
-        io.println("")
-
-        net.send(conn, resp, n)
-        net.close(conn)

examples/udp_server.zr

@@ -1,5 +1,8 @@
+include "$/io.zr"
+include "$/net.zr"
+
 func main[] : i64
-    ~s, ok := net.create_udp_server("127.0.0.1", 8000)
+    s, ok := net.create_udp_server("127.0.0.1", 8000)
     if !ok
         panic("net.create_udp_server failed")
 

src/codegen_x86_64.rs

@@ -77,14 +77,12 @@ pub struct CodegenX86_64<'a> {
     data_counter: usize,
     pub symbol_table: &'a SymbolTable,
     pub expr_types: &'a HashMap<usize, String>,
-    emit_debug: bool,
 }
 
 impl<'a> CodegenX86_64<'a> {
     pub fn new(
         symbol_table: &'a SymbolTable,
         expr_types: &'a HashMap<usize, String>,
-        emit_debug: bool,
     ) -> CodegenX86_64<'a> {
         CodegenX86_64 {
             output: String::new(),
@@ -93,7 +91,6 @@ impl<'a> CodegenX86_64<'a> {
             data_counter: 1,
             symbol_table,
             expr_types,
-            emit_debug,
         }
     }
 
@@ -103,58 +100,60 @@ impl<'a> CodegenX86_64<'a> {
     }
 
     pub fn get_output(&self) -> String {
-        format!("section .data\n{}{}", self.data_section, self.output)
+        format!(".section .data\n{}{}", self.data_section, self.output)
     }
 
     pub fn emit_prologue(&mut self, use_crt: bool) -> Result<(), ZernError> {
         emit!(
             &mut self.output,
-            "section .note.GNU-stack
-    db 0
+            ".intel_syntax noprefix
 
-section .bss
-    _heap_head: resq 1
-    _heap_tail: resq 1
-    _environ: resq 1
+.section .note.GNU-stack
+    .byte 0
 
-section .text._builtin_heap_head
+.section .bss
+    _heap_head: .zero 8
+    _heap_tail: .zero 8
+    _environ: .zero 8
+
+.section .text._builtin_heap_head
 _builtin_heap_head:
-    lea rax, [rel _heap_head]
+    lea rax, [rip + _heap_head]
     ret
 
-section .text._builtin_heap_tail
+.section .text._builtin_heap_tail
 _builtin_heap_tail:
-    lea rax, [rel _heap_tail]
+    lea rax, [rip + _heap_tail]
     ret
 
-section .text._builtin_read64
+.section .text._builtin_read64
 _builtin_read64:
-    mov rax, QWORD [rdi]
+    mov rax, QWORD PTR [rdi]
     ret
 
-section .text._builtin_set64
+.section .text._builtin_set64
 _builtin_set64:
     mov [rdi], rsi
     ret
 
-section .text._builtin_cvtsi2sd
+.section .text._builtin_cvtsi2sd
 _builtin_cvtsi2sd:
     cvtsi2sd xmm0, rdi
     movq rax, xmm0
     ret
 
-section .text._builtin_cvttsd2si
+.section .text._builtin_cvttsd2si
 _builtin_cvttsd2si:
     cvttsd2si rax, xmm0
     ret
 
-section .text._builtin_f64_to_float
-_builtin_f64_to_float:
+.section .text._builtin_f64_to_f32
+_builtin_f64_to_f32:
     cvtsd2ss xmm0, xmm0
     movd eax, xmm0
     ret
 
-section .text._builtin_syscall
+.section .text._builtin_syscall
 _builtin_syscall:
     mov rax, rdi
     mov rdi, rsi
@@ -172,26 +171,26 @@ _builtin_syscall:
             emit!(
                 &mut self.output,
                 "
-section .text._builtin_environ
+.section .text._builtin_environ
 _builtin_environ:
-    lea rax, [rel _environ]
+    lea rax, [rip + _environ]
     mov rax, [rax]
     ret
 
-global _start
-section .text
+.globl _start
+.section .text
 _start:
     xor rbp, rbp
-    ; setup args
+    // setup args
     pop rdi
     mov rsi, rsp
-    ; save environ
+    // save environ
     lea rdx, [rsi + rdi*8 + 8]
-    lea rax, [rel _environ]
+    lea rax, [rip + _environ]
     mov [rax], rdx
-    ; align stack
+    // align stack
     and rsp, -16
-    ; exit(main())
+    // exit(main())
     call main
     mov rdi, rax
     mov rax, 60
@@ -202,10 +201,10 @@ _start:
             emit!(
                 &mut self.output,
                 "
-section .text._builtin_environ
+.section .text._builtin_environ
 _builtin_environ:
-    extern environ
-    mov rax, [rel environ]
+    .extern environ
+    mov rax, [rip + environ]
     ret
 "
             );
@@ -239,7 +238,7 @@ _builtin_environ:
 
                 self.compile_expr(env, initializer)?;
                 let offset = env.define_var(name.lexeme.clone(), var_type);
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
             }
             Stmt::Assign { left, op, value } => {
                 self.compile_expr(env, value)?;
@@ -250,7 +249,7 @@ _builtin_environ:
                         let var = env.get_var(&name.lexeme).unwrap();
                         emit!(
                             &mut self.output,
-                            "    mov QWORD [rbp-{}], rax",
+                            "    mov QWORD PTR [rbp-{}], rax",
                             var.stack_offset,
                         );
                     }
@@ -266,7 +265,7 @@ _builtin_environ:
                         emit!(&mut self.output, "    pop rbx");
                         emit!(&mut self.output, "    add rbx, rax");
                         emit!(&mut self.output, "    pop rax");
-                        emit!(&mut self.output, "    mov BYTE [rbx], al");
+                        emit!(&mut self.output, "    mov BYTE PTR [rbx], al");
                     }
                     ExprKind::MemberAccess { left, field } => {
                         emit!(&mut self.output, "    push rax");
@@ -275,7 +274,7 @@ _builtin_environ:
 
                         self.compile_expr(env, left)?;
                         emit!(&mut self.output, "    pop rbx");
-                        emit!(&mut self.output, "    mov QWORD [rax+{}], rbx", offset);
+                        emit!(&mut self.output, "    mov QWORD PTR [rax+{}], rbx", offset);
                     }
                     _ => return error!(&op.loc, "invalid assignment target"),
                 };
@@ -302,7 +301,12 @@ _builtin_environ:
                             env.define_var(target.lexeme.clone(), types[i].to_string())
                         }
                     };
-                    emit!(&mut self.output, "    mov QWORD [rbp-{}], {}", offset, reg);
+                    emit!(
+                        &mut self.output,
+                        "    mov QWORD PTR [rbp-{}], {}",
+                        offset,
+                        reg
+                    );
                 }
             }
             Stmt::Const { .. } => {
@@ -365,14 +369,11 @@ _builtin_environ:
                 exported,
             } => {
                 let name = &name.lexeme;
-                if self.emit_debug || *exported || name == "main" {
-                    emit!(
-                        &mut self.output,
-                        "global {0}:function ({0}.end - {0})",
-                        name
-                    );
+                if *exported || name == "main" {
+                    emit!(&mut self.output, ".globl {0}", name);
                 }
-                emit!(&mut self.output, "section .text.{}", name);
+                emit!(&mut self.output, ".type {0}, @function", name);
+                emit!(&mut self.output, ".section .text.{}", name);
                 emit!(&mut self.output, "{}:", name);
                 emit!(&mut self.output, "    push rbp");
                 emit!(&mut self.output, "    mov rbp, rsp");
@@ -388,15 +389,20 @@ _builtin_environ:
                                 param.var_type.lexeme.clone(),
                             );
                             if let Some(reg) = REGISTERS.get(i) {
-                                emit!(&mut self.output, "    mov QWORD [rbp-{}], {}", offset, reg);
+                                emit!(
+                                    &mut self.output,
+                                    "    mov QWORD PTR [rbp-{}], {}",
+                                    offset,
+                                    reg
+                                );
                             } else {
                                 let stack_offset = 16 + 8 * (i - REGISTERS.len());
                                 emit!(
                                     &mut self.output,
-                                    "    mov rax, QWORD [rbp+{}]",
+                                    "    mov rax, QWORD PTR [rbp+{}]",
                                     stack_offset
                                 );
-                                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
                             }
                         }
                     }
@@ -423,7 +429,7 @@ _builtin_environ:
                     emit!(&mut self.output, "    ret");
                 }
 
-                emit!(&mut self.output, ".end:");
+                emit!(&mut self.output, ".size {0}, . - {0}", name);
 
                 // patch the stack size after we know how much we actually need
                 let patch = format!("    sub rsp, {:<10}", (env.next_offset + 15) & !15);
@@ -465,21 +471,29 @@ _builtin_environ:
                 let offset = env.define_var(var.lexeme.clone(), "i64".into());
 
                 self.compile_expr(env, start)?;
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
                 self.compile_expr(env, end)?;
                 let end_offset = env.next_offset;
                 env.next_offset += 8;
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", end_offset);
+                emit!(
+                    &mut self.output,
+                    "    mov QWORD PTR [rbp-{}], rax",
+                    end_offset
+                );
                 emit!(&mut self.output, "{}:", env.loop_begin_label);
-                emit!(&mut self.output, "    mov rax, QWORD [rbp-{}]", offset);
-                emit!(&mut self.output, "    mov rcx, QWORD [rbp-{}]", end_offset);
+                emit!(&mut self.output, "    mov rax, QWORD PTR [rbp-{}]", offset);
+                emit!(
+                    &mut self.output,
+                    "    mov rcx, QWORD PTR [rbp-{}]",
+                    end_offset
+                );
                 emit!(&mut self.output, "    cmp rax, rcx");
                 emit!(&mut self.output, "    jge {}", env.loop_end_label);
                 self.compile_stmt(env, body)?;
                 emit!(&mut self.output, "{}:", env.loop_continue_label);
-                emit!(&mut self.output, "    mov rax, QWORD [rbp-{}]", offset);
+                emit!(&mut self.output, "    mov rax, QWORD PTR [rbp-{}]", offset);
                 emit!(&mut self.output, "    add rax, 1");
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
                 emit!(&mut self.output, "    jmp {}", env.loop_begin_label);
                 emit!(&mut self.output, "{}:", env.loop_end_label);
                 env.pop_scope();
@@ -495,14 +509,11 @@ _builtin_environ:
                 emit!(&mut self.output, "    jmp {}", env.loop_continue_label);
             }
             Stmt::Extern(name) => {
-                emit!(&mut self.output, "extern {}", name.lexeme);
+                emit!(&mut self.output, ".extern {}", name.lexeme);
             }
             Stmt::Struct { .. } => {
                 // handled in SymbolTable
             }
-            Stmt::Enum { .. } => {
-                // handled in SymbolTable
-            }
         }
         Ok(())
     }
@@ -610,11 +621,8 @@ _builtin_environ:
                     emit!(&mut self.output, "    mov rax, {}", token.lexeme);
                 }
                 TokenType::FloatLiteral => {
-                    emit!(
-                        &mut self.output,
-                        "    mov rax, __float64__({})",
-                        token.lexeme
-                    );
+                    let value: f64 = token.lexeme.parse().unwrap();
+                    emit!(&mut self.output, "    mov rax, {}", value.to_bits());
                 }
                 TokenType::CharLiteral => {
                     emit!(
@@ -635,15 +643,15 @@ _builtin_environ:
                         .chain(std::iter::once("0".into()))
                         .collect::<Vec<_>>()
                         .join(",");
-                    emit!(&mut self.data_section, "    {} db {}", label, charcodes);
+                    emit!(&mut self.data_section, "    {}: .byte {}", label, charcodes);
                     self.data_counter += 1;
 
-                    emit!(&mut self.output, "    mov rax, {}", label);
+                    emit!(&mut self.output, "    lea rax, [rip + {}]", label);
                 }
-                TokenType::True => {
+                TokenType::KeywordTrue => {
                     emit!(&mut self.output, "    mov rax, 1");
                 }
-                TokenType::False => {
+                TokenType::KeywordFalse => {
                     emit!(&mut self.output, "    mov rax, 0");
                 }
                 _ => unreachable!(),
@@ -679,7 +687,7 @@ _builtin_environ:
                     let var = env.get_var(&name.lexeme).unwrap();
                     emit!(
                         &mut self.output,
-                        "    mov rax, QWORD [rbp-{}]",
+                        "    mov rax, QWORD PTR [rbp-{}]",
                         var.stack_offset,
                     );
                 }
@@ -767,12 +775,12 @@ _builtin_environ:
                 self.compile_expr(env, index)?;
                 emit!(&mut self.output, "    pop rbx");
                 emit!(&mut self.output, "    add rax, rbx");
-                emit!(&mut self.output, "    movzx rax, BYTE [rax]");
+                emit!(&mut self.output, "    movzx rax, BYTE PTR [rax]");
             }
             ExprKind::AddrOf { op, expr } => match &expr.kind {
                 ExprKind::Variable(name) => {
                     if self.symbol_table.functions.contains_key(&name.lexeme) {
-                        emit!(&mut self.output, "    mov rax, {}", name.lexeme);
+                        emit!(&mut self.output, "    lea rax, [rip + {}]", name.lexeme);
                     } else {
                         let var = match env.get_var(&name.lexeme) {
                             Some(x) => x,
@@ -785,7 +793,7 @@ _builtin_environ:
                         };
                         emit!(
                             &mut self.output,
-                            "    lea rax, QWORD [rbp-{}]",
+                            "    lea rax, QWORD PTR [rbp-{}]",
                             var.stack_offset,
                         );
                     }
@@ -804,7 +812,6 @@ _builtin_environ:
                 if *use_heap {
                     emit!(&mut self.output, "    mov rdi, {}", memory_size);
                     emit!(&mut self.output, "    call mem.alloc");
-                    emit!(&mut self.output, "    push rax");
                 } else {
                     let aligned_size = (memory_size + 15) & !15;
                     emit!(&mut self.output, "    sub rsp, {}", aligned_size);
@@ -821,7 +828,7 @@ _builtin_environ:
             ExprKind::MemberAccess { left, field } => {
                 let offset = self.get_field_offset(left, field)?;
                 self.compile_expr(env, left)?;
-                emit!(&mut self.output, "    mov rax, QWORD [rax+{}]", offset);
+                emit!(&mut self.output, "    mov rax, QWORD PTR [rax+{}]", offset);
             }
             ExprKind::Cast { expr, type_name: _ } => {
                 self.compile_expr(env, expr)?;
@@ -857,7 +864,11 @@ _builtin_environ:
         let mut int_idx = 0;
         for (i, arg_type) in arg_types.iter().enumerate().take(to_register) {
             let offset = 8 * (arg_count - 1 - i);
-            emit!(&mut self.output, "    mov rax, QWORD [rsp + {}]", offset);
+            emit!(
+                &mut self.output,
+                "    mov rax, QWORD PTR [rsp + {}]",
+                offset
+            );
             if arg_type == "f64" {
                 emit!(&mut self.output, "    movq xmm{}, rax", fp_idx);
                 fp_idx += 1;
@@ -875,7 +886,7 @@ _builtin_environ:
             let offset = 8 * (arg_count - 1 - arg_idx);
             emit!(
                 &mut self.output,
-                "    mov rax, QWORD [rsp + {}]",
+                "    mov rax, QWORD PTR [rsp + {}]",
                 offset + 8 * i
             );
             emit!(&mut self.output, "    push rax");

src/main.rs

@@ -5,44 +5,26 @@ mod tokenizer;
 mod typechecker;
 
 use std::{
+    collections::HashSet,
     fs,
-    path::Path,
     process::{self, Command},
 };
 
 use tokenizer::ZernError;
 
-macro_rules! parse_std_file {
-    ($statements:expr, $filename:expr) => {
-        let source: String = include_str!($filename).into();
-        let tokenizer = tokenizer::Tokenizer::new($filename.to_owned(), source);
-        let parser = parser::Parser::new(tokenizer.tokenize()?);
-        $statements.extend(parser.parse()?);
-    };
-}
-
 fn compile_file(args: Args) -> Result<(), ZernError> {
     let source = match fs::read_to_string(&args.path) {
         Ok(x) => x,
-        Err(_) => {
-            eprintln!("\x1b[91mERROR\x1b[0m: failed to open {}", args.path);
+        Err(e) => {
+            eprintln!("\x1b[91mERROR\x1b[0m: failed to open {}: {e}", args.path);
             process::exit(1);
         }
     };
 
-    let filename = Path::new(&args.path).file_name().unwrap().to_str().unwrap();
-
-    let mut statements = Vec::new();
-
-    if args.include_stdlib {
-        parse_std_file!(statements, "std/std.zr");
-        parse_std_file!(statements, "std/net.zr");
-        parse_std_file!(statements, "std/linux_constants.zr");
-    }
-
-    let tokenizer = tokenizer::Tokenizer::new(filename.to_owned(), source);
+    let mut included_paths = HashSet::new();
+    let tokenizer = tokenizer::Tokenizer::new(args.path, source, &mut included_paths);
     let parser = parser::Parser::new(tokenizer.tokenize()?);
-    statements.extend(parser.parse()?);
+    let statements = parser.parse()?;
 
     let mut symbol_table = symbol_table::SymbolTable::new();
     for stmt in &statements {
@@ -54,8 +36,7 @@ fn compile_file(args: Args) -> Result<(), ZernError> {
         typechecker.typecheck_stmt(&mut typechecker::Env::new(), stmt)?;
     }
 
-    let mut codegen =
-        codegen_x86_64::CodegenX86_64::new(&symbol_table, &typechecker.expr_types, args.emit_debug);
+    let mut codegen = codegen_x86_64::CodegenX86_64::new(&symbol_table, &typechecker.expr_types);
     codegen.emit_prologue(args.use_crt)?;
     for stmt in statements {
         codegen.compile_stmt(&mut codegen_x86_64::Env::new(), &stmt)?;
@@ -66,7 +47,9 @@ fn compile_file(args: Args) -> Result<(), ZernError> {
 
         fs::write(format!("{out}.s"), codegen.get_output()).unwrap();
 
-        run_command(format!("nasm -f elf64 -o {out}.o {out}.s"));
+        let debug_flag = if args.emit_debug { "-g" } else { "" };
+
+        run_command(format!("as --64 {debug_flag} -o {out}.o {out}.s"));
 
         if args.use_crt {
             run_command(format!(
@@ -114,7 +97,6 @@ struct Args {
     out: Option<String>,
     emit_only: bool,
     emit_debug: bool,
-    include_stdlib: bool,
     run_exe: bool,
     use_crt: bool,
     cflags: String,
@@ -129,7 +111,6 @@ impl Args {
             out: None,
             emit_only: false,
             emit_debug: false,
-            include_stdlib: true,
             run_exe: false,
             use_crt: false,
             cflags: String::new(),
@@ -146,8 +127,6 @@ impl Args {
                 }
             } else if arg == "--emit-only" {
                 out.emit_only = true;
-            } else if arg == "--no-stdlib" {
-                out.include_stdlib = false;
             } else if arg == "-r" {
                 out.run_exe = true;
             } else if arg == "-m" {
@@ -163,9 +142,7 @@ impl Args {
                     }
                 }
             } else if arg == "-h" || arg == "--help" {
-                println!(
-                    "Usage: zern [-o path] [-r] [-m] [-g] [-C cflags] [--emit-only] [--no-stdlib] path"
-                );
+                println!("Usage: zern [-o path] [-r] [-m] [-g] [-C cflags] [--emit-only] path");
                 process::exit(0);
             } else if arg.starts_with('-') {
                 eprintln!("\x1b[91mERROR\x1b[0m: unrecognized option: {arg}");

src/parser.rs

@@ -77,10 +77,6 @@ pub enum Stmt {
         name: Token,
         fields: Vec<Param>,
     },
-    Enum {
-        name: Token,
-        variants: Vec<Token>,
-    },
 }
 
 pub static NEXT_EXPR_ID: AtomicUsize = AtomicUsize::new(0);
@@ -158,6 +154,7 @@ pub struct Parser {
     tokens: Vec<Token>,
     current: usize,
     is_inside_function: bool,
+    depth: usize,
 }
 
 impl Parser {
@@ -166,6 +163,7 @@ impl Parser {
             tokens,
             current: 0,
             is_inside_function: false,
+            depth: 0,
         }
     }
 
@@ -195,9 +193,6 @@ impl Parser {
             if self.match_token(&[TokenType::KeywordStruct]) {
                 return self.struct_declaration();
             }
-            if self.match_token(&[TokenType::KeywordEnum]) {
-                return self.enum_declaration();
-            }
             return error!(
                 self.peek().loc,
                 "statements not allowed outside function body"
@@ -281,21 +276,6 @@ impl Parser {
         Ok(Stmt::Struct { name, fields })
     }
 
-    fn enum_declaration(&mut self) -> Result<Stmt, ZernError> {
-        let name = self.consume(TokenType::Identifier, "expected enum name")?;
-
-        self.consume(TokenType::Indent, "expected indent after enum name")?;
-
-        let mut variants = vec![];
-        while !self.eof() && !self.check(&TokenType::Dedent) {
-            variants.push(self.consume(TokenType::Identifier, "expected variant name")?);
-        }
-
-        self.consume(TokenType::Dedent, "expected dedent after enum variants")?;
-
-        Ok(Stmt::Enum { name, variants })
-    }
-
     fn const_declaration(&mut self) -> Result<Stmt, ZernError> {
         let name = self.consume(TokenType::Identifier, "expected const name")?;
         self.consume(TokenType::Equal, "expected '=' after const name")?;
@@ -362,7 +342,7 @@ impl Parser {
             Ok(Stmt::Break)
         } else if self.match_token(&[TokenType::KeywordContinue]) {
             Ok(Stmt::Continue)
-        } else if self.match_token(&[TokenType::Tilde]) {
+        } else if self.check(&TokenType::Identifier) && self.check_ahead(&TokenType::Comma) {
             let mut targets = vec![];
             loop {
                 targets.push(self.consume(Identifier, "expected an identifier")?);
@@ -468,7 +448,14 @@ impl Parser {
     }
 
     fn expression(&mut self) -> Result<Expr, ZernError> {
-        self.or_and()
+        self.depth += 1;
+        if self.depth > 200 {
+            return error!(self.previous().loc, "maximum expression depth reached");
+        }
+
+        let out = self.or_and();
+        self.depth -= 1;
+        out
     }
 
     fn or_and(&mut self) -> Result<Expr, ZernError> {
@@ -678,8 +665,8 @@ impl Parser {
             TokenType::FloatLiteral,
             TokenType::CharLiteral,
             TokenType::StringLiteral,
-            TokenType::True,
-            TokenType::False,
+            TokenType::KeywordTrue,
+            TokenType::KeywordFalse,
         ]) {
             Ok(Expr::new(ExprKind::Literal(self.previous().clone())))
         } else if self.match_token(&[TokenType::LeftParen]) {

src/symbol_table.rs

@@ -5,31 +5,35 @@ use crate::{
     tokenizer::{ZernError, error},
 };
 
-pub type Type = String;
-
 pub struct StructField {
     pub offset: usize,
-    pub field_type: Type,
+    pub field_type: String,
+}
+
+#[derive(Clone)]
+pub enum FnParams {
+    Normal(Vec<String>),
+    Variadic,
 }
 
 #[derive(Clone)]
 pub struct FnType {
-    pub return_type: Type,
-    pub params: Option<Vec<Type>>,
+    pub return_type: String,
+    pub params: FnParams,
 }
 
 impl FnType {
     fn new(return_type: &str, params: Vec<&str>) -> FnType {
         FnType {
             return_type: return_type.to_string(),
-            params: Some(params.iter().map(|x| x.to_string()).collect()),
+            params: FnParams::Normal(params.iter().map(|x| x.to_string()).collect()),
         }
     }
 
     fn new_variadic(return_type: &str) -> FnType {
         FnType {
             return_type: return_type.to_string(),
-            params: None,
+            params: FnParams::Variadic,
         }
     }
 }
@@ -54,8 +58,8 @@ impl SymbolTable {
                 ("_builtin_cvtsi2sd".into(), FnType::new("f64", vec!["i64"])),
                 ("_builtin_cvttsd2si".into(), FnType::new("i64", vec!["f64"])),
                 (
-                    "_builtin_f64_to_float".into(),
-                    FnType::new("i64", vec!["f64"]),
+                    "_builtin_f64_to_f32".into(),
+                    FnType::new("any", vec!["f64"]),
                 ),
                 ("_builtin_syscall".into(), FnType::new_variadic("i64")),
                 ("_builtin_environ".into(), FnType::new("ptr", vec![])),
@@ -74,11 +78,15 @@ impl SymbolTable {
                     return error!(name.loc, format!("tried to redefine '{}'", name.lexeme));
                 }
                 let mut value = if value.lexeme.starts_with("0x") {
-                    u64::from_str_radix(&value.lexeme[2..], 16).unwrap()
-                } else if value.lexeme.starts_with("0o") {
-                    u64::from_str_radix(&value.lexeme[2..], 8).unwrap()
+                    match u64::from_str_radix(&value.lexeme[2..], 16) {
+                        Ok(v) => v,
+                        Err(_) => return error!(value.loc, "failed to parse hex numeric constant"),
+                    }
                 } else {
-                    value.lexeme.parse().unwrap()
+                    match value.lexeme.parse() {
+                        Ok(v) => v,
+                        Err(_) => return error!(value.loc, "failed to parse numeric constant"),
+                    }
                 } as i64;
                 if *neg {
                     value = -value;
@@ -112,7 +120,7 @@ impl SymbolTable {
                         name.lexeme.clone(),
                         FnType {
                             return_type,
-                            params: Some(
+                            params: FnParams::Normal(
                                 params.iter().map(|x| x.var_type.lexeme.clone()).collect(),
                             ),
                         },
@@ -121,7 +129,7 @@ impl SymbolTable {
                         name.lexeme.clone(),
                         FnType {
                             return_type,
-                            params: None,
+                            params: FnParams::Variadic,
                         },
                     ),
                 };
@@ -146,16 +154,6 @@ impl SymbolTable {
 
                 self.structs.insert(name.lexeme.clone(), fields_map);
             }
-            Stmt::Enum { name, variants } => {
-                // TODO: distinct enum types
-                for (i, v) in variants.iter().enumerate() {
-                    let variant = format!("{}.{}", name.lexeme, v.lexeme);
-                    if self.is_name_defined(&variant) {
-                        return error!(name.loc, format!("tried to redefine '{}'", variant));
-                    }
-                    self.constants.insert(variant, i as i64);
-                }
-            }
             _ => {}
         }
         Ok(())

src/tokenizer.rs

@@ -1,4 +1,9 @@
-use std::{cmp::Ordering, fmt};
+use std::{
+    cmp::Ordering,
+    collections::HashSet,
+    fmt, fs,
+    path::{Path, PathBuf},
+};
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum TokenType {
@@ -25,7 +30,6 @@ pub enum TokenType {
     ShiftLeft,
     ShiftRight,
     Arrow,
-    Tilde,
 
     Equal,
     DoubleEqual,
@@ -40,8 +44,6 @@ pub enum TokenType {
     CharLiteral,
     IntLiteral,
     FloatLiteral,
-    True,
-    False,
 
     KeywordConst,
     KeywordIf,
@@ -58,7 +60,8 @@ pub enum TokenType {
     KeywordStruct,
     KeywordNew,
     KeywordAs,
-    KeywordEnum,
+    KeywordTrue,
+    KeywordFalse,
 
     Indent,
     Dedent,
@@ -110,7 +113,7 @@ pub struct Token {
     pub loc: Loc,
 }
 
-pub struct Tokenizer {
+pub struct Tokenizer<'a> {
     source: Vec<char>,
     tokens: Vec<Token>,
     indent_stack: Vec<usize>,
@@ -118,10 +121,15 @@ pub struct Tokenizer {
     start: usize,
     current: usize,
     loc: Loc,
+    included_paths: &'a mut HashSet<PathBuf>,
 }
 
-impl Tokenizer {
-    pub fn new(filename: String, source: String) -> Tokenizer {
+impl<'a> Tokenizer<'a> {
+    pub fn new(
+        filename: String,
+        source: String,
+        included_paths: &'a mut HashSet<PathBuf>,
+    ) -> Tokenizer<'a> {
         Tokenizer {
             source: source.chars().collect(),
             tokens: vec![],
@@ -134,6 +142,7 @@ impl Tokenizer {
                 line: 1,
                 column: 1,
             },
+            included_paths,
         }
     }
 
@@ -169,7 +178,6 @@ impl Tokenizer {
             '%' => self.add_token(TokenType::Mod)?,
             '^' => self.add_token(TokenType::Xor)?,
             ':' => self.add_token(TokenType::Colon)?,
-            '~' => self.add_token(TokenType::Tilde)?,
             '-' => {
                 if self.match_char('=') {
                     self.add_token(TokenType::MinusEqual)?
@@ -246,6 +254,9 @@ impl Tokenizer {
                     return error!(self.loc, "unterminated char literal");
                 }
                 _ = self.match_char('\\'); // if its an escape sequence skip \ and read one more
+                if self.eof() {
+                    return error!(self.loc, "unterminated char literal");
+                }
                 self.advance();
                 if !self.match_char('\'') {
                     return error!(self.loc, "expected ' after char literal");
@@ -258,6 +269,12 @@ impl Tokenizer {
                 while !self.eof() {
                     if self.peek() == '\\' {
                         self.advance();
+                        if self.eof() {
+                            return error!(
+                                self.loc,
+                                format!("unterminated string, started at {}", start_loc)
+                            );
+                        }
                     } else if self.peek() == '"' {
                         break;
                     } else if self.peek() == '\n' {
@@ -341,15 +358,17 @@ impl Tokenizer {
     fn scan_number(&mut self) -> Result<(), ZernError> {
         let mut is_float = false;
 
-        if self.match_char('x') {
+        if self.source[self.current - 1] == '0' && self.match_char('x') {
+            if !self.peek().is_ascii_hexdigit() {
+                return error!(self.loc, "expected a digit after '0x'");
+            }
             while self.peek().is_ascii_hexdigit() {
                 self.advance();
             }
-        } else if self.match_char('o') {
-            while matches!(self.peek(), '0'..='7') {
-                self.advance();
-            }
         } else {
+            if self.source[self.current - 1] == '0' && self.peek().is_ascii_digit() {
+                return error!(self.loc, "octal literals are not allowed");
+            }
             while self.peek().is_ascii_digit() {
                 self.advance();
             }
@@ -378,6 +397,11 @@ impl Tokenizer {
         }
 
         let lexeme: String = self.source[self.start..self.current].iter().collect();
+
+        if lexeme == "include" {
+            return self.scan_include();
+        }
+
         self.add_token(match lexeme.as_str() {
             "const" => TokenType::KeywordConst,
             "if" => TokenType::KeywordIf,
@@ -394,13 +418,77 @@ impl Tokenizer {
             "struct" => TokenType::KeywordStruct,
             "new" => TokenType::KeywordNew,
             "as" => TokenType::KeywordAs,
-            "enum" => TokenType::KeywordEnum,
-            "true" => TokenType::True,
-            "false" => TokenType::False,
+            "true" => TokenType::KeywordTrue,
+            "false" => TokenType::KeywordFalse,
             _ => TokenType::Identifier,
         })
     }
 
+    fn scan_include(&mut self) -> Result<(), ZernError> {
+        if !self.match_char(' ') {
+            return error!(self.loc, "expected a space after 'include'");
+        }
+
+        if self.peek() != '"' {
+            return error!(self.loc, "expected '\"' after 'include '");
+        }
+        self.advance();
+
+        let path_start = self.current;
+        while !self.eof() && self.peek() != '"' {
+            self.advance();
+        }
+
+        if self.eof() {
+            return error!(self.loc, "unterminated string after 'include '");
+        }
+
+        let path: String = self.source[path_start..self.current].iter().collect();
+        self.advance(); // consume closing quote
+
+        self.include_file(path)
+    }
+
+    fn include_file(&mut self, mut path: String) -> Result<(), ZernError> {
+        if path.starts_with("$/") {
+            path = find_std_path()
+                .join(&path[2..])
+                .to_string_lossy()
+                .into_owned();
+        }
+
+        let base_dir = Path::new(&self.loc.filename).parent().unwrap();
+        let resolved_path = base_dir.join(&path);
+
+        let canonical = match fs::canonicalize(&resolved_path) {
+            Ok(p) => p,
+            Err(e) => {
+                return error!(self.loc, format!("failed to resolve {}: {}", path, e));
+            }
+        };
+
+        if !self.included_paths.insert(canonical.clone()) {
+            return Ok(());
+        }
+
+        let source = match fs::read_to_string(&canonical) {
+            Ok(x) => x,
+            Err(_) => {
+                return error!(self.loc, format!("failed to include {}", path));
+            }
+        };
+
+        let tokenizer = Tokenizer::new(
+            canonical.to_string_lossy().into_owned(),
+            source,
+            &mut *self.included_paths,
+        );
+        self.tokens.extend(tokenizer.tokenize()?);
+        self.tokens.pop(); // remove inner Eof
+
+        Ok(())
+    }
+
     fn match_char(&mut self, expected: char) -> bool {
         if self.eof() || self.peek() != expected {
             false
@@ -474,3 +562,15 @@ impl Tokenizer {
         self.current >= self.source.len()
     }
 }
+
+fn find_std_path() -> PathBuf {
+    let path = std::env::current_exe().unwrap();
+
+    for dir in path.ancestors() {
+        let candidate = dir.join("std");
+        if candidate.is_dir() {
+            return candidate;
+        }
+    }
+    panic!("could not find zern std directory");
+}

src/typechecker.rs

@@ -2,7 +2,7 @@ use std::collections::HashMap;
 
 use crate::{
     parser::{Expr, ExprKind, Params, Stmt},
-    symbol_table::{SymbolTable, Type},
+    symbol_table::{FnParams, SymbolTable},
     tokenizer::{TokenType, ZernError, error},
 };
 
@@ -36,7 +36,7 @@ macro_rules! expect_types {
 static BUILTIN_TYPES: [&str; 8] = ["void", "u8", "i64", "f64", "str", "bool", "ptr", "any"];
 
 pub struct Env {
-    scopes: Vec<HashMap<String, Type>>,
+    scopes: Vec<HashMap<String, String>>,
 }
 
 impl Env {
@@ -59,7 +59,7 @@ impl Env {
         self.scopes.last_mut().unwrap().insert(name, var_type);
     }
 
-    fn get_var_type(&self, name: &str) -> Option<&Type> {
+    fn get_var_type(&self, name: &str) -> Option<&String> {
         for scope in self.scopes.iter().rev() {
             if let Some(var) = scope.get(name) {
                 return Some(var);
@@ -300,9 +300,6 @@ impl<'a> TypeChecker<'a> {
                         "unrecognized type: ".to_owned() + &return_type
                     );
                 }
-                if return_type == "f64" {
-                    return error!(&return_types[0].loc, "returning f64 not implemented yet");
-                }
 
                 self.current_function_return_type = return_type.clone();
 
@@ -364,12 +361,11 @@ impl<'a> TypeChecker<'a> {
                     }
                 }
             }
-            Stmt::Enum { .. } => {}
         }
         Ok(())
     }
 
-    pub fn typecheck_expr(&mut self, env: &mut Env, expr: &Expr) -> Result<Type, ZernError> {
+    pub fn typecheck_expr(&mut self, env: &mut Env, expr: &Expr) -> Result<String, ZernError> {
         let expr_type = match &expr.kind {
             ExprKind::Binary { left, op, right } => {
                 let left_type = self.typecheck_expr(env, left)?;
@@ -432,8 +428,8 @@ impl<'a> TypeChecker<'a> {
                 TokenType::FloatLiteral => Ok("f64".into()),
                 TokenType::CharLiteral => Ok("u8".into()),
                 TokenType::StringLiteral => Ok("str".into()),
-                TokenType::True => Ok("bool".into()),
-                TokenType::False => Ok("bool".into()),
+                TokenType::KeywordTrue => Ok("bool".into()),
+                TokenType::KeywordFalse => Ok("bool".into()),
                 _ => unreachable!(),
             },
             ExprKind::Unary { op, right } => {
@@ -468,24 +464,31 @@ impl<'a> TypeChecker<'a> {
                 if let ExprKind::Variable(callee_name) = &callee.kind {
                     if let Some(fn_type) = self.symbol_table.functions.get(&callee_name.lexeme) {
                         // its a function (defined/builtin/extern)
-                        if let Some(params) = fn_type.params.clone() {
-                            if params.len() != args.len() {
-                                return error!(
-                                    &paren.loc,
-                                    format!(
-                                        "expected {} arguments, got {}",
-                                        params.len(),
-                                        args.len()
-                                    )
-                                );
+                        match &fn_type.params {
+                            FnParams::Normal(params) => {
+                                if params.len() != args.len() {
+                                    return error!(
+                                        &paren.loc,
+                                        format!(
+                                            "expected {} arguments, got {}",
+                                            params.len(),
+                                            args.len()
+                                        )
+                                    );
+                                }
+                                for (i, arg) in args.iter().enumerate() {
+                                    expect_type!(
+                                        self.typecheck_expr(env, arg)?,
+                                        params[i],
+                                        paren.loc
+                                    );
+                                }
                             }
-                            for (i, arg) in args.iter().enumerate() {
-                                expect_type!(self.typecheck_expr(env, arg)?, params[i], paren.loc);
-                            }
-                        } else {
-                            // its a variadic function, cant check arg types
-                            for arg in args {
-                                self.typecheck_expr(env, arg)?;
+                            FnParams::Variadic => {
+                                // cant check arg types
+                                for arg in args {
+                                    self.typecheck_expr(env, arg)?;
+                                }
                             }
                         }
                         Ok(fn_type.return_type.clone())
@@ -559,13 +562,13 @@ impl<'a> TypeChecker<'a> {
                 Ok(field.field_type.clone())
             }
             ExprKind::Cast { expr, type_name } => {
-                if type_name.lexeme == "f64" {
+                let expr_type = self.typecheck_expr(env, expr)?;
+                if expr_type != "any" && type_name.lexeme == "f64" {
                     return error!(
                         &type_name.loc,
-                        "use _builtin_cvtsi2sd and _builtin_cvttsd2si to cast to f64"
+                        "use _builtin_cvtsi2sd and _builtin_cvttsd2si to cast between integers and f64"
                     );
                 }
-                self.typecheck_expr(env, expr)?;
                 if !self.is_valid_type_name(&type_name.lexeme) {
                     return error!(
                         &type_name.loc,
@@ -591,35 +594,38 @@ impl<'a> TypeChecker<'a> {
                     }
                 };
 
-                if let Some(params) = &func_type.params {
-                    if params.len() != args.len() + 1 {
-                        return error!(
-                            method.loc,
-                            format!(
-                                "expected {} arguments, got {}",
-                                params.len() - 1,
-                                args.len()
-                            )
-                        );
+                match &func_type.params {
+                    FnParams::Normal(params) => {
+                        if params.is_empty() || params[0] != receiver_type {
+                            return error!(
+                                method.loc,
+                                format!(
+                                    "first parameter of the method must be of type {}",
+                                    receiver_type
+                                )
+                            );
+                        }
+                        if params.len() != args.len() + 1 {
+                            return error!(
+                                method.loc,
+                                format!(
+                                    "expected {} arguments, got {}",
+                                    params.len() - 1,
+                                    args.len()
+                                )
+                            );
+                        }
+                        for (i, arg) in args.iter().enumerate() {
+                            expect_type!(self.typecheck_expr(env, arg)?, params[i + 1], method.loc);
+                        }
+                        Ok(func_type.return_type.clone())
                     }
-                    if params[0] != receiver_type {
-                        return error!(
-                            method.loc,
-                            format!(
-                                "first parameter of the method must be of type {}",
-                                receiver_type
-                            )
-                        );
+                    FnParams::Variadic => {
+                        for arg in args {
+                            self.typecheck_expr(env, arg)?;
+                        }
+                        Ok(func_type.return_type.clone())
                     }
-                    for (i, arg) in args.iter().enumerate() {
-                        expect_type!(self.typecheck_expr(env, arg)?, params[i + 1], method.loc);
-                    }
-                    Ok(func_type.return_type.clone())
-                } else {
-                    for arg in args {
-                        self.typecheck_expr(env, arg)?;
-                    }
-                    Ok(func_type.return_type.clone())
                 }
             }
         }?;

std/containers.zr

@@ -0,0 +1,249 @@
+include "mem.zr"
+
+struct Array
+    data: ptr
+    size: i64
+    capacity: i64
+
+func Array.new_preallocated_and_zeroed[size: i64] : Array
+    xs := new* Array
+    if size > 0
+        xs->data = mem.alloc(size * 8)
+        mem.zero(xs->data, size * 8)
+        xs->size = size
+        xs->capacity = size
+    return xs
+
+func Array.nth[xs: Array, n: i64] : any
+    if n < 0 || n >= xs->size
+        panic("Array.nth out of bounds")
+    return mem.read64(xs->data + n * 8)
+
+func Array.set[xs: Array, n: i64, x: any] : void
+    if n < 0 || n >= xs->size
+        panic("Array.set out of bounds")
+    mem.write64(xs->data + n * 8, x)
+
+func Array.push[xs: Array, x: any] : void
+    if xs->size == xs->capacity
+        new_capacity := 4
+        if xs->capacity != 0
+            new_capacity = xs->capacity * 2
+        xs->data = xs->data->realloc(new_capacity * 8)
+        xs->capacity = new_capacity
+
+    mem.write64(xs->data + xs->size * 8, x)
+    xs->size += 1
+
+func Array.free[xs: Array] : void
+    if xs->data != 0
+        xs->data->free()
+    (xs as ptr)->free()
+
+func Array.free_with_items[xs: Array] : void
+    if xs->data != 0
+        for i in 0..xs->size
+            (xs->nth(i) as ptr)->free()
+        xs->data->free()
+    (xs as ptr)->free()
+
+func Array.pop[xs: Array] : any
+    if xs->size == 0
+        panic("Array.pop on empty array")
+    x : any = Array.last(xs)
+    xs->size = xs->size - 1
+    return x
+
+func Array.last[xs: Array] : any
+    if xs->size == 0
+        panic("Array.last on empty array")
+    return xs->nth(xs->size - 1)
+
+func Array.slice[xs: Array, start: i64, length: i64] : Array
+    if start < 0 || length < 0 || start + length > xs->size
+        panic("Array.slice out of bounds")
+
+    new_array := Array.new_preallocated_and_zeroed(length)
+    mem.copy(xs->data + start * 8, new_array->data, length * 8)
+    return new_array
+
+func Array.concat[a: Array, b: Array] : Array
+    new_array := Array.new_preallocated_and_zeroed(a->size + b->size)
+    mem.copy(a->data, new_array->data, a->size * 8)
+    mem.copy(b->data, new_array->data + a->size * 8, b->size * 8)
+    return new_array
+
+func Array.quicksort[arr: Array] : void
+    arr->_do_quicksort(0, arr->size - 1)
+
+func Array._do_quicksort[arr: Array, low: i64, high: i64] : void
+    if low < high
+        i := arr->_partition(low, high)
+        arr->_do_quicksort(low, i - 1)
+        arr->_do_quicksort(i + 1, high)
+
+func Array._partition[arr: Array, low: i64, high: i64] : i64
+    pivot : i64 = arr->nth(high)
+    i := low - 1
+    for j in (low)..high
+        if arr->nth(j) as i64 <= pivot
+            i += 1
+            temp : i64 = arr->nth(i)
+            arr->set(i, arr->nth(j))
+            arr->set(j, temp)
+    temp : i64 = arr->nth(i + 1)
+    arr->set(i + 1, arr->nth(high))
+    arr->set(high, temp)
+    return i + 1
+
+func Array.contains_str[arr: Array, s: str] : bool
+    for i in 0..arr->size
+        if (arr->nth(i) as str)->equal(s)
+            return true
+    return false
+
+func Array.count[arr: Array, item: any] : i64
+    count := 0
+    for i in 0..arr->size
+        if arr->nth(i) == item
+            count += 1
+    return count
+
+func Array.map[arr: Array, fn: ptr] : Array
+    out := Array.new_preallocated_and_zeroed(arr->size)
+    for i in 0..arr->size
+        out->set(i, fn(arr->nth(i)))
+    return out
+
+func Array.filter[arr: Array, fn: ptr] : Array
+    out := []
+    for i in 0..arr->size
+        if fn(arr->nth(i))
+            out->push(arr->nth(i))
+    return out
+
+func Array.reduce[arr: Array, fn: ptr, acc: any] : any
+    for i in 0..arr->size
+        acc = fn(acc, arr->nth(i))
+    return acc
+
+func str.split[haystack: str, needle: str]: Array
+    haystack_len := haystack->len()
+    needle_len := needle->len()
+    result := []
+    
+    if !needle_len
+        if !haystack_len
+            return result
+        else
+            for i in 0..haystack_len
+                result->push(haystack->substr_n(i, 1))
+            return result
+
+    start := 0
+    i := 0
+    while i < haystack_len
+        if i <= haystack_len - needle_len
+            match := true
+            for j in 0..needle_len
+                if haystack[i + j] != needle[j]
+                    match = false
+                    break
+            if match
+                result->push(haystack->substr_n(start, i - start))
+                start = i + needle_len
+                i += needle_len
+                continue
+        i += 1
+
+    result->push(haystack->substr_n(start, haystack_len - start))
+    return result
+
+const HashMap._TABLE_SIZE = 100
+
+struct HashMap
+    table: Array
+
+struct HashMap._Node
+    key: str
+    value: any
+    next: HashMap._Node
+
+func HashMap.new[] : HashMap
+    map := new* HashMap
+    map->table = Array.new_preallocated_and_zeroed(HashMap._TABLE_SIZE)
+    return map
+
+func HashMap.insert[map: HashMap, key: str, value: any] : void
+    index := HashMap._djb2(key)
+    current : HashMap._Node = map->table->nth(index)
+
+    while current as ptr
+        if current->key->equal(key)
+            current->value = value
+            return
+        current = current->next
+
+    new_node := new* HashMap._Node
+    new_node->key = key->make_copy()
+    new_node->value = value
+    new_node->next = map->table->nth(index)
+    map->table->set(index, new_node)
+
+func HashMap.get[map: HashMap, key: str] : any, bool
+    index := HashMap._djb2(key)
+    current : HashMap._Node = map->table->nth(index)
+
+    while current as ptr
+        if current->key->equal(key)
+            return current->value, true
+        current = current->next
+    
+    return 0 as any, false
+
+func HashMap.delete[map: HashMap, key: str] : void
+    index := HashMap._djb2(key)
+    current : HashMap._Node = map->table->nth(index)
+    prev := 0 as HashMap._Node
+
+    while current as ptr
+        if current->key->equal(key)
+            if prev as ptr
+                prev->next = current->next
+            else
+                map->table->set(index, current->next)
+            
+            current->key->free()
+            (current as ptr)->free()
+            return
+
+        prev = current
+        current = current->next
+
+func HashMap.keys[map: HashMap] : Array
+    out := []
+    for i in 0..HashMap._TABLE_SIZE
+        current : HashMap._Node = map->table->nth(i)
+        while current as ptr
+            out->push(current->key)
+            current = current->next
+    return out
+
+func HashMap.free_with_keys[map: HashMap] : void
+    for i in 0..HashMap._TABLE_SIZE
+        current : HashMap._Node = map->table->nth(i)
+        while current as ptr
+            tmp := current
+            current = current->next
+            tmp->key->free()
+            (tmp as ptr)->free()
+
+    map->table->free()
+    (map as ptr)->free()
+
+func HashMap._djb2[key: str] : i64
+    hash := 5381 
+    for i in 0..key->len()
+        hash = ((hash << 5) + hash) + key[i]
+    hash = (hash & 0x7fffffffffffffff) // prevent negative
+    return hash % HashMap._TABLE_SIZE

std/io.zr

@@ -0,0 +1,152 @@
+include "str.zr"
+include "os.zr"
+
+func panic[msg: str] : void
+    io.printf("PANIC: %s\n", msg)
+    // for gdb backtrace
+    _builtin_syscall(SYS_kill, os.getpid(), SIGABRT)
+    os.exit(1)
+
+func assert[cond: bool, msg: str] : void
+    if !cond
+        panic(msg)
+
+func io.printf[..] : void
+    s := _var_arg(0) as ptr
+    i := 1
+
+    while s[0]
+        if s[0] == '%'
+            s += 1
+
+            if s[0] == 'd'
+                io.print_i64(_var_arg(i) as i64)
+                i += 1
+            else if s[0] == 'x'
+                io.print_i64_hex(_var_arg(i) as i64)
+                i += 1
+            else if s[0] == 's'
+                io.print(_var_arg(i) as str)
+                i += 1
+            else if s[0] == 'c'
+                io.print_char(_var_arg(i) as u8)
+                i += 1
+            else if s[0] == 'f'
+                io.print_f64(_var_arg(i) as i64)
+                i += 1
+            else if s[0] == '%'
+                io.print_char('%')
+            else if s[0] == 0
+                break
+            else
+                panic("io.printf: unrecognized format")
+        else
+            io.print_char(s[0])
+        s += 1
+
+func io.print_sized[x: ptr, size: i64] : void
+    _builtin_syscall(SYS_write, STDOUT_FILENO, x, size)
+
+func io.print[x: str] : void
+    io.print_sized(x as ptr, x->len())
+
+func io.println[x: str] : void
+    io.print(x)
+    io.print("\n")
+
+func io.print_char[x: u8] : void
+    io.print_sized(^x, 1)
+
+func io.print_bool[x: bool] : void
+    if x
+        io.print("true")
+    else
+        io.print("false")
+
+func io.print_i64[x: i64] : void
+    s := _stackalloc(21)
+    x->to_str_buf(s)
+    io.print(s as str)
+
+func io.print_i64_hex[x: i64] : void
+    s := _stackalloc(17)
+    x->to_hex_str_buf(s)
+    io.print(s as str)
+
+func io.println_i64[x: i64] : void
+    s := _stackalloc(21)
+    x->to_str_buf(s)
+    io.println(s as str)
+
+// TODO: fix when we implement f64 params
+func io.print_f64[x: i64] : void
+    s := _stackalloc(64)
+    f64.to_str_buf(x, s)
+    io.print(s as str)
+
+func io.read_char[] : u8
+    c := 0 as u8
+    _builtin_syscall(SYS_read, STDIN_FILENO, ^c, 1)
+    return c
+
+func io.read_line[] : str
+    b := new str.Builder
+    while true
+        c := io.read_char()
+        if c == '\n'
+            break
+        b->append_char(c)
+    return b->build_and_free_buffer()
+
+func io.read_text_file[path: str] : str, bool
+    fd := _builtin_syscall(SYS_openat, AT_FDCWD, path, O_RDONLY, 0)
+    if fd < 0
+        return 0 as str, false
+
+    size := _builtin_syscall(SYS_lseek, fd, 0, SEEK_END)
+    _builtin_syscall(SYS_lseek, fd, 0, SEEK_SET)
+
+    buffer := mem.alloc(size + 1)
+    n := _builtin_syscall(SYS_read, fd, buffer, size)
+    _builtin_syscall(SYS_close, fd)
+
+    if n != size
+        buffer->free()
+        return 0 as str, false
+
+    buffer[n] = 0
+    return buffer as str, true
+
+func io.read_binary_file[path: str] : Blob, bool
+    fd := _builtin_syscall(SYS_openat, AT_FDCWD, path, O_RDONLY, 0)
+    if fd < 0
+        return 0 as Blob, false
+    
+    buf := new* Blob
+    buf->size = _builtin_syscall(SYS_lseek, fd, 0, SEEK_END)
+    _builtin_syscall(SYS_lseek, fd, 0, SEEK_SET)
+
+    buf->data = mem.alloc(buf->size)
+
+    n := _builtin_syscall(SYS_read, fd, buf->data, buf->size)
+    _builtin_syscall(SYS_close, fd)
+
+    if n != buf->size
+        buf->free()
+        return 0 as Blob, false
+
+    return buf, true
+
+func io.write_text_file[path: str, content: str] : bool
+    return io.write_binary_file(path, content as ptr, content->len())
+
+func io.write_binary_file[path: str, content: ptr, size: i64] : bool
+    fd := _builtin_syscall(SYS_openat, AT_FDCWD, path, O_WRONLY|O_CREAT|O_TRUNC, math.octal_to_decimal(644))
+    if fd < 0
+        return false
+
+    n := _builtin_syscall(SYS_write, fd, content, size)
+    _builtin_syscall(SYS_close, fd)
+    if n != size
+        return false
+    return true

std/json.zr

@@ -0,0 +1,203 @@
+include "containers.zr"
+
+const json.OBJECT = 0
+const json.ARRAY  = 1
+const json.STRING = 2
+const json.NUMBER = 3
+const json.NULL   = 4
+const json.BOOL   = 5
+
+struct json.Value
+    type: i64
+    value: any
+
+func json.Value.dump[v: json.Value] : str
+    s := new str.Builder
+
+    if v->type == json.OBJECT
+        map := v->value as HashMap
+        keys := map->keys()
+        s->append_char('{')
+        for i in 0..keys->size
+            if i > 0
+                s->append_char(',')
+            s->append_char('"')
+            s->append(keys->nth(i) as str)
+            s->append_char('"')
+            s->append_char(':')
+            value, _ := map->get(keys->nth(i) as str)
+            s->append((value as json.Value)->dump())
+        s->append_char('}')
+        keys->free()
+    else if v->type == json.ARRAY
+        arr := v->value as Array
+        s->append_char('[')
+        for i in 0..arr->size
+            if i > 0
+                s->append_char(',')
+            s->append((arr->nth(i) as json.Value)->dump())
+        s->append_char(']')
+    else if v->type == json.STRING
+        // TODO: escape sequences
+        s->append_char('"')
+        s->append(v->value as str)
+        s->append_char('"')
+    else if v->type == json.NUMBER
+        s->append((v->value as i64)->to_str())
+    else if v->type == json.NULL
+        s->append("null")
+    else if v->type == json.BOOL
+        if v->value as bool
+            s->append("true")
+        else
+            s->append("false")
+    else
+        panic("json.Value.dump: unknown value type")
+    
+    return s->build_and_free_buffer()
+
+func json.Value.free[v: json.Value] : void
+    if v->type == json.OBJECT
+        map := v->value as HashMap
+        keys := map->keys()
+        for i in 0..keys->size
+            value, _ := map->get(keys->nth(i) as str)
+            (value as json.Value)->free()
+        keys->free()
+        
+        map->free_with_keys()
+    else if v->type == json.ARRAY
+        arr := v->value as Array
+        for i in 0..arr->size
+            (arr->nth(i) as json.Value)->free()
+        arr->free()
+    else if v->type == json.STRING
+        (v->value as str)->free()
+
+    (v as ptr)->free()
+
+func json.val[x: any] : any
+    return (x as json.Value)->value
+
+func json.parse[s: str] : json.Value
+    i := 0
+    return json._parse_value(s, ^i)
+
+func json._parse_value[s: str, i: ptr] : json.Value
+    out := new* json.Value
+
+    json._skip_whitespace(s, i)
+
+    if s[mem.read64(i)] == 0
+        panic("json.parse: unexpected EOF")
+    
+    if s[mem.read64(i)] == '{'
+        mem.write64(i, mem.read64(i) + 1)
+        json._skip_whitespace(s, i)
+
+        out->type = json.OBJECT
+        out->value = HashMap.new()
+        
+        if s[mem.read64(i)] != '}'
+            while true
+                json._skip_whitespace(s, i)
+                key := json._parse_string(s, i)
+                json._skip_whitespace(s, i)
+
+                if s[mem.read64(i)] != ':'
+                    panic("json.parse: expected ':'")
+                mem.write64(i, mem.read64(i) + 1)
+                json._skip_whitespace(s, i)
+
+                value := json._parse_value(s, i)
+                (out->value as HashMap)->insert(key, value)
+                key->free()
+
+                json._skip_whitespace(s, i)
+                if s[mem.read64(i)] == ','
+                    mem.write64(i, mem.read64(i) + 1)
+                else
+                    break
+        
+        json._skip_whitespace(s, i)
+        if s[mem.read64(i)] != '}'
+            panic("json.parse: expected '}'")
+        mem.write64(i, mem.read64(i) + 1)
+    else if s[mem.read64(i)] == '['
+        mem.write64(i, mem.read64(i) + 1)
+        json._skip_whitespace(s, i)
+
+        out->type = json.ARRAY
+        out->value = []
+        
+        while s[mem.read64(i)] != ']'
+            json._skip_whitespace(s, i)
+
+            (out->value as Array)->push(json._parse_value(s, i))
+            json._skip_whitespace(s, i)
+
+            if s[mem.read64(i)] == ','
+                mem.write64(i, mem.read64(i) + 1)
+            else
+                break
+        
+        json._skip_whitespace(s, i)
+        if s[mem.read64(i)] != ']'
+            panic("json.parse: expected ']'")
+        mem.write64(i, mem.read64(i) + 1)
+    else if s[mem.read64(i)] == '"'
+        out->type = json.STRING
+        out->value = json._parse_string(s, i)
+    else if s[mem.read64(i)]->is_digit() || s[mem.read64(i)] == '-'
+        start := mem.read64(i)
+
+        if s[mem.read64(i)] == '-'
+            mem.write64(i, mem.read64(i) + 1)
+
+        while s[mem.read64(i)]->is_digit()
+            mem.write64(i, mem.read64(i) + 1)
+        // TODO: float support once str.parse_f64 is a thing
+        if s[mem.read64(i)] == '.'
+            panic("json.parse: parsing floats not implemented yet")
+
+        len := mem.read64(i) - start
+
+        num_str := s->substr_n(start, len)
+        out->type = json.NUMBER
+        out->value = num_str->parse_i64()
+        num_str->free()
+    else if s[mem.read64(i)] == 'n' && s[mem.read64(i)+1] == 'u' && s[mem.read64(i)+2] == 'l' && s[mem.read64(i)+3] == 'l'
+        out->type = json.NULL
+        mem.write64(i, mem.read64(i) + 4)
+    else if s[mem.read64(i)] == 't' && s[mem.read64(i)+1] == 'r' && s[mem.read64(i)+2] == 'u' && s[mem.read64(i)+3] == 'e'
+        out->type = json.BOOL
+        out->value = true
+        mem.write64(i, mem.read64(i) + 4)
+    else if s[mem.read64(i)] == 'f' && s[mem.read64(i)+1] == 'a' && s[mem.read64(i)+2] == 'l' && s[mem.read64(i)+3] == 's' && s[mem.read64(i)+4] == 'e'
+        out->type = json.BOOL
+        out->value = false
+        mem.write64(i, mem.read64(i) + 5)
+    else
+        panic("json.parse: unexpected character")
+
+    return out
+
+func json._parse_string[s: str, i: ptr] : str
+    if s[mem.read64(i)] != '"'
+        panic("json.parse: expected '\"'")
+    mem.write64(i, mem.read64(i) + 1)
+
+    start := mem.read64(i)
+    // TODO: escape sequences
+    while s[mem.read64(i)] != '"'
+        if s[mem.read64(i)] == 0
+            panic("json.parse: unexpected EOF")
+        mem.write64(i, mem.read64(i) + 1)
+
+    len := mem.read64(i) - start
+    mem.write64(i, mem.read64(i) + 1)
+    return s->substr_n(start, len)
+
+func json._skip_whitespace[s: str, i: ptr] : void
+    while s[mem.read64(i)]->is_whitespace()
+        mem.write64(i, mem.read64(i) + 1)

std/linux_syscalls.zr

@@ -1,29 +1,3 @@
-const STDIN         = 0
-const STDOUT        = 1
-
-const SIGABRT       = 6
-
-const AT_FDCWD      = -100
-
-const S_IFDIR       = 0o040000
-const S_IFMT        = 0o170000
-
-const PROT_READ     = 1
-const PROT_WRITE    = 2
-
-const MAP_PRIVATE   = 2
-const MAP_ANONYMOUS = 32
-
-const O_RDONLY      = 0
-const O_WRONLY      = 1
-const O_CREAT       = 64
-const O_TRUNC       = 512
-
-const SEEK_SET      = 0
-const SEEK_END      = 2
-
-const F_OK          = 0
-
 const SYS_read                    =  0
 const SYS_write                   =  1
 const SYS_open                    =  2

std/mem.zr

@@ -0,0 +1,237 @@
+include "linux_syscalls.zr"
+include "num.zr"
+
+const MEM_BLOCK_SIZE = 32
+
+struct mem.Block
+    size: i64
+    free: bool
+    next: mem.Block
+    prev: mem.Block
+
+func mem.align[x: i64] : i64
+    return (x + 7) & -8
+
+func mem.Block._split[blk: mem.Block, needed: i64] : void
+    if blk->size >= needed + MEM_BLOCK_SIZE + 8
+        new_blk := (blk as ptr + MEM_BLOCK_SIZE + needed) as mem.Block
+        new_blk->size = blk->size - needed - MEM_BLOCK_SIZE
+        new_blk->free = true
+        new_blk->next = blk->next
+        new_blk->prev = blk
+
+        if blk->next as ptr
+            blk->next->prev = new_blk
+        else
+            mem.write64(_builtin_heap_tail(), new_blk)
+
+        blk->size = needed
+        blk->next = new_blk
+
+func mem._request_space[size: i64] : mem.Block
+    needed := size + MEM_BLOCK_SIZE
+    alloc_size := (needed + 4095) & -4096
+
+    blk := _builtin_syscall(SYS_mmap, 0, alloc_size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) as mem.Block
+    if (blk as ptr as i64) == MAP_FAILED
+        panic("mem._request_space: failed to mmap")
+
+    blk->size = alloc_size - MEM_BLOCK_SIZE
+    blk->free = false
+    blk->next = 0 as mem.Block
+    blk->prev = 0 as mem.Block
+
+    tail := mem.read64(_builtin_heap_tail()) as mem.Block
+    if tail as ptr
+        tail->next = blk
+        blk->prev = tail
+
+    mem.write64(_builtin_heap_tail(), blk)
+    return blk
+
+func mem.alloc[size: i64] : ptr
+    if size <= 0
+        panic("mem.alloc: called with nonpositive size")
+
+    size = mem.align(size)
+
+    cur := mem.read64(_builtin_heap_head()) as mem.Block
+    while cur as ptr
+        if cur->free && cur->size >= size
+            cur->_split(size)
+            cur->free = false
+            return cur as ptr + MEM_BLOCK_SIZE
+        cur = cur->next
+    
+    blk := mem._request_space(size)
+    
+    if !mem.read64(_builtin_heap_head())
+        mem.write64(_builtin_heap_head(), blk)
+    
+    blk->_split(size)
+    
+    return blk as ptr + MEM_BLOCK_SIZE
+
+func ptr.free[x: ptr] : void
+    if x == 0
+        return
+
+    blk := (x - MEM_BLOCK_SIZE) as mem.Block
+    if blk->free
+        return
+
+    blk->free = true
+
+    next := blk->next
+    if next as ptr && next->free
+        expected_next := (blk as ptr + MEM_BLOCK_SIZE + blk->size) as mem.Block
+        if expected_next as ptr == next as ptr
+            blk->size += MEM_BLOCK_SIZE + next->size
+            blk->next = next->next
+            if next->next as ptr
+                next->next->prev = blk
+            if mem.read64(_builtin_heap_tail()) == next as ptr
+                mem.write64(_builtin_heap_tail(), blk)
+
+    prev := blk->prev
+    if prev as ptr && prev->free
+        expected_blk := (prev as ptr + MEM_BLOCK_SIZE + prev->size) as mem.Block
+        if expected_blk as ptr == blk as ptr
+            prev->size += MEM_BLOCK_SIZE + blk->size
+            prev->next = blk->next
+            if blk->next as ptr
+                blk->next->prev = prev
+            if mem.read64(_builtin_heap_tail()) == blk as ptr
+                mem.write64(_builtin_heap_tail(), prev)
+            blk = prev
+
+    block_total := blk->size + MEM_BLOCK_SIZE
+    if (blk as i64 & 4095) == 0 && (block_total & 4095) == 0
+        if blk->prev as ptr
+            blk->prev->next = blk->next
+        else
+            mem.write64(_builtin_heap_head(), blk->next)
+        if blk->next as ptr
+            blk->next->prev = blk->prev
+        else
+            mem.write64(_builtin_heap_tail(), blk->prev)
+        _builtin_syscall(SYS_munmap, blk, block_total)
+
+func ptr.realloc[x: ptr, new_size: i64] : ptr
+    if !x
+        return mem.alloc(new_size)
+    
+    if new_size < 0
+        panic("mem.realloc: called with negative new_size")
+
+    if new_size == 0
+        x->free()
+        return 0 as ptr
+
+    new_size = mem.align(new_size)
+
+    blk := (x - MEM_BLOCK_SIZE) as mem.Block
+    if blk->size >= new_size
+        blk->_split(new_size)
+        return x
+
+    next := blk->next
+    expected_next := (blk as ptr + MEM_BLOCK_SIZE + blk->size) as mem.Block
+    
+    if next as ptr && next->free && expected_next as ptr == next as ptr
+        combined := blk->size + MEM_BLOCK_SIZE + next->size
+        if combined >= new_size
+            blk->size = combined
+            blk->next = next->next
+            if next->next as ptr
+                next->next->prev = blk
+            if mem.read64(_builtin_heap_tail()) == next as ptr
+                mem.write64(_builtin_heap_tail(), blk)
+            blk->_split(new_size)
+            return x
+
+    new_ptr := mem.alloc(new_size)
+
+    mem.copy(x, new_ptr, math.min(blk->size, new_size))
+    x->free()
+    return new_ptr
+
+func ptr.zero_and_free[x: ptr, size: i64] : void
+    mem.zero(x, size)
+    x->free()
+
+func mem.zero[x: ptr, size: i64] : void
+    i := 0
+    while i + 8 <= size
+        mem.write64(x + i, 0)
+        i += 8
+    while i < size
+        x[i] = 0 as u8
+        i += 1
+
+func mem.copy[src: ptr, dst: ptr, n: i64] : void
+    if dst > src && dst < src + n
+        i := n
+        while i - 8 >= 0
+            i -= 8
+            mem.write64(dst + i, mem.read64(src + i))
+        while i > 0
+            i -= 1
+            dst[i] = src[i]
+    else
+        i := 0
+        while i + 8 <= n
+            mem.write64(dst + i, mem.read64(src + i))
+            i += 8
+        while i < n
+            dst[i] = src[i]
+            i += 1
+
+func mem.read8[x: ptr] : u8
+    return x[0]
+
+func mem.read16[x: ptr] : i64
+    return x[0] as i64 | (x[1] << 8)
+
+func mem.read16be[x: ptr] : i64
+    return (x[0] << 8) as i64 | x[1]
+
+func mem.read32[x: ptr] : i64
+    return x[0] as i64 | (x[1] << 8) | (x[2] << 16) | (x[3] << 24)
+
+func mem.read32be[x: ptr] : i64
+    return (x[0] as i64 << 24) | (x[1] << 16) | (x[2] << 8) | x[3]
+
+func mem.read64[x: ptr] : i64
+    return _builtin_read64(x)
+
+func mem.write32[x: ptr, d: i64] : void
+    x[0] = d & 0xff
+    x[1] = (d >> 8) & 0xff
+    x[2] = (d >> 16) & 0xff
+    x[3] = (d >> 24) & 0xff
+
+func mem.write16[x: ptr, d: i64] : void
+    x[0] = d & 0xff
+    x[1] = (d >> 8) & 0xff
+
+func mem.write16be[x: ptr, d: i64] : void
+    x[0] = (d >> 8) & 0xff
+    x[1] = d & 0xff
+
+func mem.write64[x: ptr, d: any] : void
+    _builtin_set64(x, d)
+
+struct Blob
+    data: ptr
+    size: i64
+
+func Blob.alloc[size: i64] : Blob
+    buffer := new* Blob
+    buffer->size = size
+    buffer->data = mem.alloc(size)
+    return buffer
+
+func Blob.free[buf: Blob] : void
+    buf->data->free()
+    (buf as ptr)->free()

std/net.zr

@@ -1,3 +1,5 @@
+include "os.zr"
+
 const AF_INET = 2
 const SOCK_STREAM = 1
 const SOCK_DGRAM = 2
@@ -20,7 +22,7 @@ func net.listen[host: str, port: i64] : i64, bool
         _builtin_syscall(SYS_close, s)
         return -1, false
     
-    ~packed_host, ok := net.resolve(host)
+    packed_host, ok := net.resolve(host)
     if !ok
         return -1, false
 
@@ -42,7 +44,7 @@ func net.connect[host: str, port: i64] : i64, bool
     if s < 0
         return -1, false
     
-    ~packed_host, ok := net.resolve(host)
+    packed_host, ok := net.resolve(host)
     if !ok
         return -1, false
 
@@ -99,18 +101,18 @@ func net.UDPSocket.receive[s: net.UDPSocket, size: i64] : net.UDPPacket
 func net.UDPSocket.close_and_free[s: net.UDPSocket] : void
     _builtin_syscall(SYS_close, s->fd)
     s->addr->free()
-    mem.free(s)
+    (s as ptr)->free()
 
 func net.create_udp_client[host: str, port: i64] : net.UDPSocket, bool
     s := new* net.UDPSocket
 
-    ~packed_host, ok := net.resolve(host)
+    packed_host, ok := net.resolve(host)
     if !ok
         return 0 as net.UDPSocket, false
 
     s->fd = _builtin_syscall(SYS_socket, AF_INET, SOCK_DGRAM, 0)
     if s->fd < 0
-        mem.free(s)
+        (s as ptr)->free()
         return 0 as net.UDPSocket, false
 
     s->addr = mem.alloc(16)
@@ -118,7 +120,7 @@ func net.create_udp_client[host: str, port: i64] : net.UDPSocket, bool
     return s, true
 
 func net.create_udp_server[host: str, port: i64] : net.UDPSocket, bool
-    ~s, ok := net.create_udp_client(host, port)
+    s, ok := net.create_udp_client(host, port)
     if !ok
         return 0 as net.UDPSocket, false
 
@@ -139,7 +141,7 @@ struct net.UDPPacket
 func net.UDPPacket.free[pkt: net.UDPPacket] : void
     pkt->data->free()
     pkt->source_addr->free()
-    mem.free(pkt)
+    (pkt as ptr)->free()
 
 func net.resolve[domain: str] : i64, bool
     // if domain is already an ip, skip dns resolution
@@ -170,7 +172,7 @@ func net.resolve[domain: str] : i64, bool
     query := net.build_dns_query(domain, DNS_TYPE_A)
 
     // TODO: this probably shouldnt be hardcoded
-    ~s, ok := net.create_udp_client("1.1.1.1", 53)
+    s, ok := net.create_udp_client("1.1.1.1", 53)
     if !ok
         query->free()
         return -1, false

std/num.zr

@@ -0,0 +1,220 @@
+include "io.zr"
+
+func i64.abs[n: i64] : i64
+    if n == -9223372036854775808
+        panic("MIN_I64 passed to math.abs")
+    if n < 0
+        return -n
+    return n
+
+func i64.sign[n: i64] : i64
+    if n < 0
+        return -1
+    else if n > 0
+        return 1
+    else
+        return 0
+
+func i64.isqrt[n: i64] : i64
+    if n < 0
+        panic("negative number passed to math.isqrt")
+    if n == 0 || n == 1
+        return n
+
+    guess := n
+    next_guess := (guess + n / guess) / 2
+
+    while next_guess < guess
+        guess = next_guess
+        next_guess = (guess + n / guess) / 2
+
+    return guess
+
+func i64.is_prime[n: i64]: bool
+    if n <= 1
+        return false
+    if n == 2 || n == 3
+        return true
+    if n % 2 == 0 || n % 3 == 0
+        return false
+
+    i := 5
+    while i * i <= n
+        if n % i == 0 || n % (i + 2) == 0
+            return false
+        i += 6
+    return true
+
+func i64.to_str_buf[n: i64, buf: ptr] : void
+    if n == 0
+        buf[0] = '0'
+        buf[1] = 0
+        return
+
+    neg : bool = n < 0
+    if neg
+        // MIN_I64 will fail but i so dont care
+        n = -n
+    tmp := _stackalloc(21)
+    end := 20
+    tmp[end] = 0
+    end -= 1
+    for i in 0..19
+        if n == 0
+            break
+        tmp[end] = '0' + (n % 10)
+        n = n / 10
+        end -= 1
+    if neg
+        tmp[end] = '-'
+        end -= 1
+    len := 19 - end
+    for i in 0..len
+        buf[i] = tmp[end + 1 + i]
+    buf[len] = 0
+
+func i64.to_hex_str_buf[n: i64, buf: ptr] : void
+    hex_chars := "0123456789abcdef"
+
+    if n == 0
+        buf[0] = '0'
+        buf[1] = 0
+        return
+
+    mask := (1 << 60) - 1
+    tmp := _stackalloc(17)
+    len := 0
+
+    for i in 0..16
+        if n == 0
+            break
+        tmp[len] = hex_chars[n & 15]
+        n = (n >> 4) & mask
+        len += 1
+
+    for j in 0..len
+        buf[j] = tmp[len - 1 - j]
+
+    buf[len] = 0
+
+func i64.to_str[n: i64] : str
+    out := mem.alloc(21)
+    n->to_str_buf(out)
+    return out as str
+
+func i64.to_hex_str[n: i64] : str
+    out := mem.alloc(17)
+    n->to_hex_str_buf(out)
+    return out as str
+
+func f64.to_str_buf[x: i64, buf: ptr] : void
+    bits := x
+    sign := (bits >> 63) & 1
+    exp := (bits >> 52) & 0x7ff
+    mant := bits & 0x000fffffffffffff
+
+    if exp == 0x7ff
+        panic("invalid float")
+
+    p := 0
+    if sign
+        buf[p] = '-'
+        p += 1
+        bits = bits & 0x7fffffffffffffff
+
+    if exp == 0 && mant == 0
+        buf[p] = '0'
+        buf[p+1] = '.'
+        buf[p+2] = '0'
+        buf[p+3] = 0
+        return
+
+    sig := mant
+    if exp != 0
+        sig = sig | 0x0010000000000000
+
+    shift := exp - 1075
+
+    if shift >= 0
+        (sig << shift)->to_str_buf(buf + p)
+        while buf[p]
+            p += 1
+        buf[p] = '.'
+        buf[p+1] = '0'
+        buf[p+2] = 0
+        return
+
+    ns := -shift
+
+    if ns <= 52
+        int_part := sig >> ns
+        int_part->to_str_buf(buf + p)
+        while buf[p]
+            p += 1
+    else
+        buf[p] = '0'
+        p += 1
+
+    buf[p] = '.'
+    p += 1
+
+    mask := (1 << ns) - 1
+    frac := sig & mask
+
+    for i in 0..6
+        if frac == 0
+            if i > 0
+                break
+            buf[p] = '0'
+            p += 1
+            break
+        frac = frac * 10
+        digit := frac >> ns
+        buf[p] = '0' + digit as u8
+        p += 1
+        frac = frac & mask
+    buf[p] = 0
+
+func math.gcd[a: i64, b: i64] : i64
+    a = a->abs()
+    b = b->abs()
+    while b != 0
+        tmp := b
+        b = a % b
+        a = tmp
+    return a
+
+func math.min[a: i64, b: i64] : i64
+    if a < b
+        return a
+    return b
+
+func math.max[a: i64, b: i64] : i64
+    if a > b
+        return a
+    return b
+
+func math.pow[b: i64, e: i64] : i64
+    if e < 0
+        panic("negative exponent passed to math.pow")
+    out := 1
+    while e > 0
+        if e & 1
+            out = out * b
+        b = b * b
+        e = e >> 1
+    return out
+
+func math.lcm[a: i64, b: i64] : i64
+    return (a / math.gcd(a, b)) * b
+
+func math.octal_to_decimal[octal: i64] : i64
+    decimal := 0
+    base := 1
+
+    while octal > 0
+        digit := octal % 10
+        decimal += digit * base
+        base = base * 8
+        octal = octal / 10
+    return decimal

std/os.zr

@@ -0,0 +1,154 @@
+include "posix.zr"
+include "linux_syscalls.zr"
+include "str.zr"
+include "containers.zr"
+
+func os.exit[code: i64] : void
+    _builtin_syscall(SYS_exit, code)
+
+func os.getpid[] : i64
+    return _builtin_syscall(SYS_getpid)
+
+func os.arg[argv: ptr, n: i64] : str
+    return mem.read64(argv + n * 8) as str
+
+func os.getenv[name: str] : str, bool
+    name_len := name->len()
+    i := 0
+    while true
+        entry := mem.read64(_builtin_environ() + i * 8) as str
+        if entry as ptr == 0
+            break
+        if entry->equal_n(name, name_len) && entry[name_len] == '='
+            return (entry as ptr + name_len + 1) as str, true
+        i += 1
+    return 0 as str, false
+
+func os.basename[path: str] : str
+    len := path->len()
+    end := len
+    while end > 0 && path[end - 1] == '/'
+        end -= 1
+
+    if end == 0
+        return "/"
+
+    i := end - 1
+    while i >= 0 && path[i] != '/'
+        i -= 1
+
+    return path->substr_n(i + 1, end - i - 1)
+
+struct os.Timespec
+    tv_sec: i64
+    tv_nsec: i64
+
+func os.sleep[ms: i64] : void
+    if ms < 0
+        panic("negative time passed to os.sleep")
+    req := new os.Timespec
+    req->tv_sec = ms / 1000
+    req->tv_nsec = (ms % 1000) * 1000000
+    _builtin_syscall(SYS_nanosleep, req, 0)
+
+func os.time[] : i64
+    ts := new os.Timespec
+    _builtin_syscall(SYS_clock_gettime, CLOCK_REALTIME, ts)
+    out := ts->tv_sec * 1000 + ts->tv_nsec / 1000000
+    return out
+
+func os.urandom_buf[buf: ptr, n: i64] : void
+    pos := 0
+    while pos < n
+        ret := _builtin_syscall(SYS_getrandom, buf + pos, n - pos, 0)
+        if ret <= 0
+            panic("os.urandom_buf: syscall failed")
+        pos += ret
+
+func os.urandom[n: i64]: ptr
+    buf := mem.alloc(n)
+    os.urandom_buf(buf, n)
+    return buf
+
+func os.urandom_i64[] : i64
+    n := 0
+    os.urandom_buf(^n, 8)
+    return n
+
+func os.run_shell_command[command: str] : i64, bool
+    pid := _builtin_syscall(SYS_fork)
+    if pid < 0
+        return -1, false
+
+    if pid == 0
+        argv := ["sh", "-c", command, 0] // gets freed after child process exits
+        _builtin_syscall(SYS_execve, "/bin/sh", argv->data, _builtin_environ())
+        os.exit(1)
+    else
+        status := 0
+        wp := _builtin_syscall(SYS_wait4, pid, ^status, 0, 0)
+        if wp < 0
+            return -1, false
+        st := status & 0xffffffff
+        
+        if (st & 0x7f) == 0
+            return (st >> 8) & 0xff, true
+        else
+            return -(st & 0x7f), true
+
+func os.file_exists[path: str] : bool
+    return _builtin_syscall(SYS_faccessat, AT_FDCWD, path, F_OK, 0) == 0
+
+func os.get_file_size[path: str] : i64, bool
+    st := _stackalloc(256) // it has 21 mixed-size fields so ptr for now
+
+    rc := _builtin_syscall(SYS_newfstatat, AT_FDCWD, path, st, 0)
+    if rc != 0
+        return 0, false
+
+    return mem.read64(st + 48), true
+
+func os.is_a_directory[path: str] : bool
+    st := _stackalloc(256) // it has 21 mixed-size fields so ptr for now
+
+    rc := _builtin_syscall(SYS_newfstatat, AT_FDCWD, path, st, 0)
+    if rc != 0
+        return false
+
+    return (mem.read32(st + 24) & S_IFMT) == S_IFDIR
+
+func os.list_directory[path: str] : Array, bool
+    fd := _builtin_syscall(SYS_openat, AT_FDCWD, path, O_RDONLY, 0)
+    if fd < 0
+        return 0 as Array, false
+
+    files := []
+    buf := _stackalloc(1024)
+    while true
+        n := _builtin_syscall(SYS_getdents64, fd, buf, 1024)
+        if n < 0
+            files->free_with_items()
+            _builtin_syscall(SYS_close, fd)
+            return 0 as Array, false
+        else if n == 0
+            break
+
+        pos := 0
+        while pos < n
+            len := mem.read16(buf + pos + 16)
+            name : ptr = buf + pos + 19
+            if name[0]
+                skip := false
+                // skip if name is exactly '.' or '..'
+                if name[0] == '.'
+                    if name[1] == 0
+                        skip = true
+                    else if name[1] == '.'
+                        if name[2] == 0
+                            skip = true
+                if !skip
+                    files->push((name as str)->make_copy())
+            pos += len
+
+    _builtin_syscall(SYS_close, fd)
+    return files, true

std/posix.zr

@@ -0,0 +1,32 @@
+const STDIN_FILENO  = 0
+const STDOUT_FILENO = 1
+
+const SIGABRT = 6
+
+const AT_FDCWD = -100
+
+const S_IFDIR = 16384
+const S_IFMT  = 61440
+
+const PROT_NONE  = 0
+const PROT_READ  = 1
+const PROT_WRITE = 2
+const PROT_EXEC  = 4
+
+const MAP_FAILED          = -1
+const MAP_SHARED          = 1
+const MAP_PRIVATE         = 2
+const MAP_FIXED           = 16
+const MAP_ANONYMOUS       = 32
+
+const O_RDONLY = 0
+const O_WRONLY = 1
+const O_CREAT  = 64
+const O_TRUNC  = 512
+
+const SEEK_SET = 0
+const SEEK_END = 2
+
+const F_OK = 0
+
+const CLOCK_REALTIME = 0

std/str.zr

@@ -0,0 +1,299 @@
+include "num.zr"
+include "mem.zr"
+
+func u8.is_whitespace[x: u8] : bool
+    return x == ' ' || x == '\n' || x == '\t' || x == '\r'
+
+func u8.is_digit[x: u8] : bool
+    return x >= '0' && x <= '9'
+
+func u8.is_hex_digit[x: u8] : bool
+    return (x >= '0' && x <= '9') || (x >= 'a' && x <= 'f') || (x >= 'A' && x <= 'F')
+
+func u8.is_lowercase[x: u8] : bool
+    return x >= 'a' && x <= 'z'
+
+func u8.is_uppercase[x: u8] : bool
+    return x >= 'A' && x <= 'Z'
+
+func u8.is_letter[x: u8] : bool
+    return x->is_uppercase() || x->is_lowercase()
+
+func u8.is_alphanumeric[x: u8] : bool
+    return x->is_letter() || x->is_digit()
+
+func u8.to_str[c: u8] : str
+    s := mem.alloc(2) as str
+    s[0] = c
+    s[1] = 0
+    return s
+
+func str.free[s: str] : void
+    (s as ptr)->free()
+
+func str.len[s: str] : i64
+    i := 0
+    while s[i]
+        i += 1
+    return i
+
+func str.make_copy[s: str] : str
+    size := s->len() + 1
+    dup := mem.alloc(size) as str
+    mem.copy(s as ptr, dup as ptr, size)
+    return dup
+
+func str.equal[a: str, b: str] : bool
+    i := 0
+    while a[i] != 0 && b[i] != 0
+        if a[i] != b[i]
+            return false
+        i += 1
+    return a[i] == b[i]
+
+func str.equal_n[a: str, b: str, n: i64] : bool
+    i := 0
+    while i < n
+        if a[i] == 0 || b[i] == 0
+            return false
+        if a[i] != b[i]
+            return false
+        i += 1
+    return true
+
+func str.format_into[..] : i64
+    buf := _var_arg(0) as ptr
+    size := _var_arg(1) as i64
+    if size <= 0
+        return 0
+    s := _var_arg(2) as ptr
+    i := 3
+    n := 0
+
+    tmp := _stackalloc(64) as str
+
+    while s[0]
+        if s[0] == '%'
+            s += 1
+
+            if s[0] == 'd'
+                (_var_arg(i) as i64)->to_str_buf(tmp as ptr)
+                tmp_len := tmp->len()
+                remaining := size - n - 1
+                mem.copy(tmp as ptr, buf + n, math.min(tmp_len, remaining))
+                n += tmp_len
+                i += 1
+            else if s[0] == 'x'
+                (_var_arg(i) as i64)->to_hex_str_buf(tmp as ptr)
+                tmp_len := tmp->len()
+                remaining := size - n - 1
+                mem.copy(tmp as ptr, buf + n, math.min(tmp_len, remaining))
+                n += tmp_len
+                i += 1
+            else if s[0] == 's'
+                tmp_str := _var_arg(i) as str
+                tmp_len := tmp_str->len()
+                remaining := size - n - 1
+                mem.copy(tmp_str as ptr, buf + n, math.min(tmp_len, remaining))
+                n += tmp_len
+                i += 1
+            else if s[0] == 'c'
+                if n < size - 1
+                    buf[n] = _var_arg(i) as u8
+                n += 1
+                i += 1
+            else if s[0] == 'f'
+                // TODO: use arrow when we implement f64 params
+                f64.to_str_buf(_var_arg(i), tmp as ptr)
+                tmp_len := tmp->len()
+                remaining := size - n - 1
+                mem.copy(tmp as ptr, buf + n, math.min(tmp_len, remaining))
+                n += tmp_len
+                i += 1
+            else if s[0] == '%'
+                if n < size - 1
+                    buf[n] = '%'
+                n += 1
+            else if s[0] == 0
+                break
+            else
+                panic("str.format_into: unrecognized format")
+        else
+            if n < size - 1
+                buf[n] = s[0]
+            n += 1
+        s += 1
+
+    if n < size
+        buf[n] = 0
+    else if size > 0
+        buf[size - 1] = 0
+    return n
+
+func str.concat[a: str, b: str] : str
+    a_len := a->len()
+    b_len := b->len()
+    out := mem.alloc(a_len + b_len + 1) as str
+    mem.copy(a as ptr, out as ptr, a_len)
+    mem.copy(b as ptr, out as ptr + a_len, b_len)
+    out[a_len + b_len] = 0
+    return out
+
+func str.contains[haystack: str, needle: str] : bool
+    return haystack->find(needle) != -1
+
+func str.find[haystack: str, needle: str] : i64
+    haystack_len := haystack->len()
+    needle_len := needle->len()
+
+    if needle_len == 0
+        return 0
+    
+    if needle_len > haystack_len
+        return -1
+
+    for i in 0..(haystack_len - needle_len + 1)
+        if haystack[i] != needle[0]
+            continue
+        if needle_len == 1
+            return i
+        match := true
+        for j in 1..needle_len
+            if haystack[i + j] != needle[j]
+                match = false
+                break
+        if match
+            return i
+    return -1
+
+func str.substr_n[s: str, start: i64, length: i64] : str
+    out := mem.alloc(length + 1) as str
+    mem.copy(s as ptr + start, out as ptr, length)
+    out[length] = 0
+    return out
+
+func str.trim[s: str] : str
+    len := s->len()
+    if len == 0
+        out := mem.alloc(1) as str
+        out[0] = 0
+        return out
+
+    start := 0
+    end := len - 1
+
+    while start <= end && s[start]->is_whitespace()
+        start += 1
+
+    while end >= start && s[end]->is_whitespace()
+        end -= 1
+
+    return s->substr_n(start, end - start + 1)
+
+func str.reverse[s: str] : str
+    len := s->len()
+    out := mem.alloc(len + 1) as str
+
+    for i in 0..len
+        out[i] = s[len - i - 1]
+    out[len] = 0
+    return out
+
+
+func str.parse_i64[s: str] : i64
+    len := s->len()
+    i := 0
+
+    sign := 1
+    if i < len && s[i] == '-'
+        sign = -1
+        i += 1
+
+    num := 0
+    while i < len
+        d := s[i]
+        if !d->is_digit()
+            break
+        num = num * 10 + (d - '0')
+        i += 1
+    return num * sign
+
+func str.hex_encode[s: str, s_len: i64] : str
+    hex_chars := "0123456789abcdef"
+    out := mem.alloc(s_len * 2 + 1) as str
+
+    for i in 0..s_len
+        b := s[i]
+        out[i * 2]     = hex_chars[(b >> 4) & 15]
+        out[i * 2 + 1] = hex_chars[b & 15]
+
+    out[s_len * 2] = 0
+    return out
+
+func str._hex_digit_to_int[d: u8] : u8
+    if d->is_digit()
+        return d - '0'
+    lower : u8 = d | 32 
+    if lower >= 'a' && lower <= 'f'
+        return lower - 'a' + 10
+    panic("invalid hex digit passed to str._hex_digit_to_int")
+
+func str.hex_decode[s: str] : str
+    s_len := s->len()
+    if s_len % 2 != 0
+        panic("invalid hex string passed to str.hex_decode")
+
+    out_len := s_len / 2
+    out := mem.alloc(out_len + 1) as str
+
+    for i in 0..out_len
+        high := str._hex_digit_to_int(s[i * 2])
+        low := str._hex_digit_to_int(s[i * 2 + 1])
+        out[i] = (high << 4) | low
+
+    out[out_len] = 0
+    return out
+
+struct str.Builder
+    data: ptr
+    size: i64
+    capacity: i64
+
+func str.Builder._grow[b: str.Builder, needed: i64] : void
+    if b->size + needed > b->capacity
+        new_capacity := 64
+        if b->capacity != 0
+            new_capacity = b->capacity * 2
+        while new_capacity < b->size + needed
+            new_capacity = new_capacity * 2
+        b->data = b->data->realloc(new_capacity)
+        b->capacity = new_capacity
+
+func str.Builder.append_char[b: str.Builder, c: u8] : void
+    b->_grow(1)
+    b->data[b->size] = c
+    b->size += 1
+
+func str.Builder.append[b: str.Builder, s: str] : void
+    len := s->len()
+    b->_grow(len)
+    mem.copy(s as ptr, b->data + b->size, len)
+    b->size += len
+
+func str.Builder.build[b: str.Builder] : str
+    s := mem.alloc(b->size + 1) as str
+    mem.copy(b->data, s as ptr, b->size)
+    s[b->size] = 0
+    return s
+
+func str.Builder.build_and_free_buffer[b: str.Builder] : str
+    s := b->build()
+    b->free_buffer()
+    return s
+
+func str.Builder.free_buffer[b: str.Builder] : void
+    if b->data != 0
+        b->data->free()
+    b->size = 0
+    b->capacity = 0
+

test.zr

@@ -1,3 +1,6 @@
+include "$/io.zr"
+include "$/os.zr"
+
 struct TestRunner
     build_blacklist: Array
     run_blacklist: Array
@@ -5,7 +8,7 @@ struct TestRunner
     custom_run_args: HashMap
 
 func TestRunner.run_directory[tr: TestRunner, dir: str] : void
-    ~files, ok := os.list_directory(dir)
+    files, ok := os.list_directory(dir)
     if !ok
         panic("failed to open test directory")
     for i in 0..files->size
@@ -25,12 +28,12 @@ func TestRunner.run_test[tr: TestRunner, x: str] : void
     io.printf("Building %s...\n", x)
 
     build_cmd := "./target/release/zern "->concat(x)
-    ~custom_build_flags, ok := tr->custom_build_flags->get(name)
+    custom_build_flags, ok := tr->custom_build_flags->get(name)
     if ok
         build_cmd = build_cmd->concat(" ")->concat(custom_build_flags)
 
     build_start_time := os.time()
-    ~status, ok := os.run_shell_command(build_cmd)
+    status, ok := os.run_shell_command(build_cmd)
     if !ok || status != 0
         os.exit(1)
     build_end_time := os.time()
@@ -44,12 +47,12 @@ func TestRunner.run_test[tr: TestRunner, x: str] : void
     io.printf("Running %s...\n", x)
 
     run_cmd := "./out"
-    ~custom_run_args, ok := tr->custom_run_args->get(name)
+    custom_run_args, ok := tr->custom_run_args->get(name)
     if ok
         run_cmd = run_cmd->concat(" ")->concat(custom_run_args)
 
     run_start_time := os.time()
-    ~status, ok := os.run_shell_command(run_cmd)
+    status, ok := os.run_shell_command(run_cmd)
     if !ok || status != 0
         io.println("Test failed.")
         os.exit(1)
@@ -58,17 +61,18 @@ func TestRunner.run_test[tr: TestRunner, x: str] : void
     io.printf("Running %s took %dms\n", x, run_end_time - run_start_time)
 
 func main[] : i64
-    ~status, ok := os.run_shell_command("cargo build --release")
+    status, ok := os.run_shell_command("cargo build --release")
     if !ok || status != 0
         os.exit(1)
 
     tr := new TestRunner
     tr->build_blacklist = []
-    tr->run_blacklist = ["raylib.zr", "sqlite_todo.zr", "guess_number.zr", "udp_server.zr", "chip8.zr", "tcp_server.zr"]
+    tr->run_blacklist = ["raylib.zr", "sqlite_todo.zr", "guess_number.zr", "udp_server.zr", "chip8.zr", "serve.zr"]
     tr->custom_build_flags = HashMap.new()
     tr->custom_build_flags->insert("raylib.zr", "-m -C \"-lraylib\"")
     tr->custom_build_flags->insert("chip8.zr", "-m -C \"-lraylib\"")
     tr->custom_build_flags->insert("sqlite_todo.zr", "-m -C \"-lsqlite3\"")
+    tr->custom_build_flags->insert("serve.zr", "-m -C \"-lpthread\"")
     tr->custom_run_args = HashMap.new()
     tr->custom_run_args->insert("curl.zr", "http://example.com")