implement str.from_i64

README.md

@@ -5,7 +5,7 @@ A very cool language
 ## Features
 * Clean indentation-based syntax
 * Compiles to x86_64 Assembly
-* ~~No libc required~~ (SOON; still used for `malloc,realloc,free,snprintf,system,gethostbyname`)
+* ~~No libc required~~ (SOON; still used for memory allocation and DNS resolution)
 * Produces tiny static executables (~50KB with musl)
 * Sometimes works
 * Has the pipe operator

src/codegen_x86_64.rs

@@ -105,8 +105,7 @@ section .text
 "
         );
 
-        // take that rustfmt
-        for name in "malloc,realloc,free,snprintf,system,gethostbyname".split(",") {
+        for name in &["malloc", "realloc", "free", "system", "gethostbyname"] {
             emit!(&mut self.output, "extern {}", name);
             emit!(&mut self.output, "c.{} equ {}", name, name);
         }

src/std.zr

@@ -104,7 +104,7 @@ func str.len[s: String] : I64
 func str.copy[s: String] : String
     let size: I64 = str.len(s) + 1
     let dup: String = mem.alloc(size)
-    for i in 0..size+1
+    for i in 0..size
         str.set(dup, i, s[i])
     return dup
 
@@ -203,10 +203,31 @@ func str.reverse[s: String] : String
     str.set(out, len, 0)
     return out
 
+// not sure this covers all wacky edge cases
 func str.from_i64[n: I64] : String
-    let x: String = mem.alloc(21)
-    c.snprintf(x, 21, "%ld", n)
-    return x
+    if n == 0
+        let s: String = mem.alloc(2)
+        str.set(s, 0, '0')
+        str.set(s, 1, 0)
+        return s
+
+    let neg: Bool = n < 0
+    if neg
+        n = -n
+    let buf: String = mem.alloc(21)
+    let i: I64 = 0
+    while n > 0
+        let d: U8 = n % 10
+        str.set(buf, i, '0' + d)
+        n = n / 10
+        i = i + 1
+    if neg
+        str.set(buf, i, '-')
+        i = i + 1
+    str.set(buf, i, 0)
+    let s: String = str.reverse(buf)
+    mem.free(buf)
+    return s
 
 func str.parse_i64[s: String] : I64
     let len: I64 = str.len(s)