Add JS_NewTwoByteString (#1000)

Fixes: #992

Author: bnoordhuis

api-test.c

@@ -233,6 +233,42 @@ static void module_serde(void)
     JS_FreeRuntime(rt);
 }
 
+static void two_byte_string(void)
+{
+    JSRuntime *rt = JS_NewRuntime();
+    JSContext *ctx = JS_NewContext(rt);
+    {
+        JSValue v = JS_NewTwoByteString(ctx, NULL, 0);
+        assert(!JS_IsException(v));
+        const char *s = JS_ToCString(ctx, v);
+        assert(s);
+        assert(!strcmp(s, ""));
+        JS_FreeCString(ctx, s);
+        JS_FreeValue(ctx, v);
+    }
+    {
+        JSValue v = JS_NewTwoByteString(ctx, (uint16_t[]){'o','k'}, 2);
+        assert(!JS_IsException(v));
+        const char *s = JS_ToCString(ctx, v);
+        assert(s);
+        assert(!strcmp(s, "ok"));
+        JS_FreeCString(ctx, s);
+        JS_FreeValue(ctx, v);
+    }
+    {
+        JSValue v = JS_NewTwoByteString(ctx, (uint16_t[]){0xD800}, 1);
+        assert(!JS_IsException(v));
+        const char *s = JS_ToCString(ctx, v);
+        assert(s);
+        // questionable but surrogates don't map to UTF-8 without WTF-8
+        assert(!strcmp(s, "\xED\xA0\x80"));
+        JS_FreeCString(ctx, s);
+        JS_FreeValue(ctx, v);
+    }
+    JS_FreeContext(ctx);
+    JS_FreeRuntime(rt);
+}
+
 int main(void)
 {
     sync_call();
@@ -241,5 +277,6 @@ int main(void)
     raw_context_global_var();
     is_array();
     module_serde();
+    two_byte_string();
     return 0;
 }

quickjs.c

@@ -4030,6 +4030,19 @@ JSValue JS_NewStringLen(JSContext *ctx, const char *buf, size_t buf_len)
     return JS_MKPTR(JS_TAG_STRING, str);
 }
 
+JSValue JS_NewTwoByteString(JSContext *ctx, const uint16_t *buf, size_t len)
+{
+    JSString *str;
+
+    if (!len)
+        return JS_AtomToString(ctx, JS_ATOM_empty_string);
+    str = js_alloc_string(ctx, len, 1);
+    if (!str)
+        return JS_EXCEPTION;
+    memcpy(str16(str), buf, len * sizeof(*buf));
+    return JS_MKPTR(JS_TAG_STRING, str);
+}
+
 static JSValue JS_ConcatString3(JSContext *ctx, const char *str1,
                                 JSValue str2, const char *str3)
 {

quickjs.h

@@ -761,6 +761,10 @@ JS_EXTERN JSValue JS_NewStringLen(JSContext *ctx, const char *str1, size_t len1)
 static inline JSValue JS_NewString(JSContext *ctx, const char *str) {
     return JS_NewStringLen(ctx, str, strlen(str));
 }
+// makes a copy of the input; does not check if the input is valid UTF-16,
+// that is the responsibility of the caller
+JS_EXTERN JSValue JS_NewTwoByteString(JSContext *ctx, const uint16_t *buf,
+                                      size_t len);
 JS_EXTERN JSValue JS_NewAtomString(JSContext *ctx, const char *str);
 JS_EXTERN JSValue JS_ToString(JSContext *ctx, JSValueConst val);
 JS_EXTERN JSValue JS_ToPropertyKey(JSContext *ctx, JSValueConst val);