Broken site based impl

lib/stdlib/string.js

@@ -0,0 +1,143 @@
+// Converts any value to a string, like the spec's ToString
+function String(x) {
+    switch (typeof x) {
+        case "string": return x;
+        case "number": return __native_number_to_string(x);
+        case "boolean": return x ? "true" : "false";
+        case "undefined": return "undefined";
+        case "function": return "function () { [native code] }";
+        case "object":
+            if (x === null) return "null";
+            if (typeof x.toString === "function") return x.toString();
+            return "[object Object]";
+    }
+}
+
+String.fromCharCode = function (code) {
+    return __native_string_from_char_code(code);
+};
+
+// In these methods `this` is the primitive string itself
+String.prototype = {
+    toString() { return this; },
+    valueOf() { return this; },
+
+    // ── Characters ──
+    charAt(i) {
+        if (i < 0 || i >= this.length) return "";
+        return __native_string_slice(this, i, i + 1);
+    },
+    charCodeAt(i) {
+        if (i < 0 || i >= this.length) return NaN;
+        return __native_string_char_code_at(this, i);
+    },
+    at(i) {
+        if (i < 0) i += this.length;
+        if (i < 0 || i >= this.length) return undefined;
+        return __native_string_slice(this, i, i + 1);
+    },
+
+    // ── Search ──
+    indexOf(search, from) {
+        let start = from === undefined ? 0 : clampIndex(from, this.length);
+        for (let i = start; i + search.length <= this.length; i++) {
+            if (__native_string_slice(this, i, i + search.length) === search) return i;
+        }
+        return -1;
+    },
+    lastIndexOf(search) {
+        for (let i = this.length - search.length; i >= 0; i--) {
+            if (__native_string_slice(this, i, i + search.length) === search) return i;
+        }
+        return -1;
+    },
+    includes(search, from) { return this.indexOf(search, from) !== -1; },
+    startsWith(search, from) {
+        let start = from === undefined ? 0 : clampIndex(from, this.length);
+        return __native_string_slice(this, start, start + search.length) === search;
+    },
+    endsWith(search, end) {
+        let stop = end === undefined ? this.length : clampIndex(end, this.length);
+        let start = stop - search.length;
+        return start >= 0 && __native_string_slice(this, start, stop) === search;
+    },
+
+    // ── Substrings ──
+    slice(start, end) {
+        let len = this.length;
+        let s = relativeIndex(start === undefined ? 0 : start, len);
+        let e = relativeIndex(end === undefined ? len : end, len);
+        return s < e ? __native_string_slice(this, s, e) : "";
+    },
+    substring(start, end) {
+        let len = this.length;
+        let s = clampIndex(start === undefined ? 0 : start, len);
+        let e = clampIndex(end === undefined ? len : end, len);
+        return s < e ? __native_string_slice(this, s, e) : __native_string_slice(this, e, s);
+    },
+
+    // ── Case ──
+    toUpperCase() { return mapCodes(this, 97, 122, -32); }, // a-z to A-Z
+    toLowerCase() { return mapCodes(this, 65, 90, 32); },   // A-Z to a-z
+
+    // ── Whitespace ──
+    trim() { return this.trimStart().trimEnd(); },
+    trimStart() {
+        let i = 0;
+        while (i < this.length && isSpace(__native_string_char_code_at(this, i))) i++;
+        return __native_string_slice(this, i, this.length);
+    },
+    trimEnd() {
+        let i = this.length;
+        while (i > 0 && isSpace(__native_string_char_code_at(this, i - 1))) i--;
+        return __native_string_slice(this, 0, i);
+    },
+
+    // ── Building ──
+    repeat(count) {
+        let s = "";
+        for (let i = 0; i < count; i++) s = __native_string_concat(s, this);
+        return s;
+    },
+    padStart(length, fill) { return pad(this, length, fill, true); },
+    padEnd(length, fill) { return pad(this, length, fill, false); },
+};
+
+__link_proto_string(String.prototype);
+
+// An index clamped to [0, len]
+function clampIndex(i, len) {
+    return i < 0 ? 0 : i > len ? len : i;
+}
+
+// An index where a negative value counts from the end, clamped to [0, len]
+function relativeIndex(i, len) {
+    return clampIndex(i < 0 ? i + len : i, len);
+}
+
+// `s` with every char code in [lo, hi] moved by `shift`, for ASCII case mapping
+function mapCodes(s, lo, hi, shift) {
+    let out = "";
+    for (let i = 0; i < s.length; i++) {
+        let c = __native_string_char_code_at(s, i);
+        if (c >= lo && c <= hi) c += shift;
+        out = __native_string_concat(out, __native_string_from_char_code(c));
+    }
+    return out;
+}
+
+function isSpace(c) {
+    // tab, line feed, vertical tab, form feed, carriage return, space, nbsp
+    return (c >= 9 && c <= 13) || c === 32 || c === 160;
+}
+
+function pad(s, length, fill, atStart) {
+    let f = fill === undefined ? " " : String(fill);
+    if (s.length >= length || f.length === 0) return s;
+
+    let padding = "";
+    while (padding.length < length - s.length) padding = __native_string_concat(padding, f);
+    padding = __native_string_slice(padding, 0, length - s.length);
+
+    return atStart ? __native_string_concat(padding, s) : __native_string_concat(s, padding);
+}