js: make vlib/v/util compile on JS backend (#12660)

vlib/builtin/js/builtin.v

@@ -83,3 +83,9 @@ pub fn error_with_code(message string, code int) IError {
 		code: code
 	}
 }
+
+// free allows for manually freeing memory allocated at the address `ptr`. no-op on JS backend
+[unsafe]
+pub fn free(ptr voidptr) {
+	_ := ptr
+}

vlib/builtin/js/string.js.v

@@ -955,3 +955,23 @@ pub fn tos(jsstr JS.String) string {
 
 	return res
 }
+
+pub fn (s string) compare(a string) int {
+	min_len := if s.len < a.len { s.len } else { a.len }
+	for i in 0 .. min_len {
+		if s[i] < a[i] {
+			return -1
+		}
+		if s[i] > a[i] {
+			return 1
+		}
+	}
+
+	if s.len < a.len {
+		return -1
+	}
+	if s.len > a.len {
+		return 1
+	}
+	return 0
+}

vlib/builtin/js/utf8.js.v

@@ -11,3 +11,7 @@ pub fn utf8_str_visible_length(s string) int {
 pub fn utf8_str_len(s string) int {
 	return s.len
 }
+
+pub fn utf8_char_len(b byte) int {
+	return ((0xe5000000 >> ((b >> 3) & 0x1e)) & 3) + 1
+}

vlib/os/os_js.js.v

@@ -125,3 +125,14 @@ pub fn getwd() string {
 
 	return res
 }
+
+pub fn getuid() int {
+	res := 0
+	#if (process.getuid) res.val = process.getuid();
+
+	return res
+}
+
+pub fn execvp(cmd string, args []string) ? {
+	panic('os.execvp() is not available on JS backend')
+}

vlib/v/util/util.c.v

@@ -0,0 +1,17 @@
+module util
+
+pub fn skip_bom(file_content string) string {
+	mut raw_text := file_content
+	// BOM check
+	if raw_text.len >= 3 {
+		unsafe {
+			c_text := raw_text.str
+			if c_text[0] == 0xEF && c_text[1] == 0xBB && c_text[2] == 0xBF {
+				// skip three BOM bytes
+				offset_from_begin := 3
+				raw_text = tos(c_text[offset_from_begin], vstrlen(c_text) - offset_from_begin)
+			}
+		}
+	}
+	return raw_text
+}

vlib/v/util/util.js.v

@@ -0,0 +1,15 @@
+module util
+
+pub fn skip_bom(file_content string) string {
+	mut raw_text := file_content
+	if raw_text.len >= 3 {
+		js_text := raw_text.str
+		_ := js_text
+		#if (js_text.charCodeAt(0) == 0xEF && js_text.charCodeAt(1) == 0xBB && js_text.charCodeAt(2) == 0xBF)
+
+		{
+			#raw_text.str = js_text.slice(3,js_text.length);
+		}
+	}
+	return raw_text
+}

vlib/v/util/util.v

@@ -282,12 +282,14 @@ pub fn cached_read_source_file(path string) ?string {
 	if isnil(cache) {
 		cache = &SourceCache{}
 	}
+
 	if path.len == 0 {
 		unsafe { cache.sources.free() }
 		unsafe { free(cache) }
 		cache = &SourceCache(0)
 		return error('memory source file cache cleared')
 	}
+
 	// eprintln('>> cached_read_source_file path: $path')
 	if res := cache.sources[path] {
 		// eprintln('>> cached')
@@ -300,26 +302,6 @@ pub fn cached_read_source_file(path string) ?string {
 	return res
 }
 
-pub fn read_file(file_path string) ?string {
-	return unsafe { cached_read_source_file(file_path) }
-}
-
-pub fn skip_bom(file_content string) string {
-	mut raw_text := file_content
-	// BOM check
-	if raw_text.len >= 3 {
-		unsafe {
-			c_text := raw_text.str
-			if c_text[0] == 0xEF && c_text[1] == 0xBB && c_text[2] == 0xBF {
-				// skip three BOM bytes
-				offset_from_begin := 3
-				raw_text = tos(c_text[offset_from_begin], vstrlen(c_text) - offset_from_begin)
-			}
-		}
-	}
-	return raw_text
-}
-
 pub fn replace_op(s string) string {
 	return match s {
 		'+' { '_plus' }
@@ -528,3 +510,7 @@ pub fn free_caches() {
 		cached_read_source_file('') or { '' }
 	}
 }
+
+pub fn read_file(file_path string) ?string {
+	return unsafe { cached_read_source_file(file_path) }
+}