785 lines
18 KiB
TypeScript
785 lines
18 KiB
TypeScript
// Supported specifiers set: [diuoxXaAfeEgGcspq%]
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// Supported flags set: [-+0# ]
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// Width and precision via digits or `*`
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type FormatSpec = {
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flags: number; // FLAG_*
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width: number;
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hasPrec: boolean;
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prec: number;
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spec: number;
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};
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const FLAG_MINUS = 1;
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const FLAG_PLUS = 2;
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const FLAG_ZERO = 4;
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const FLAG_HASH = 8;
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const FLAG_SPACE = 16;
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function isDigit(c: number): boolean {
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return c >= 48 && c <= 57; // '0'..'9'
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}
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// Parse a format spec starting after '%' and return index of specifier.
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function parseSpec(
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fmt: string,
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start: number,
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): { spec: FormatSpec; end: number } {
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let i = start;
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const len = fmt.length;
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let flags = 0;
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outer: while (i < len) {
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switch (fmt.charCodeAt(i)) {
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case 45:
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flags |= FLAG_MINUS;
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i++;
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break; // '-'
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case 43:
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flags |= FLAG_PLUS;
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i++;
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break; // '+'
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case 48:
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flags |= FLAG_ZERO;
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i++;
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break; // '0'
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case 35:
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flags |= FLAG_HASH;
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i++;
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break; // '#'
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case 32:
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flags |= FLAG_SPACE;
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i++;
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break; // ' '
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default:
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break outer;
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}
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}
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// Parse width
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let width = 0;
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if (i < len && fmt.charCodeAt(i) === 42) {
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// '*'
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width = -1;
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i++;
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} else {
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while (i < len && isDigit(fmt.charCodeAt(i))) {
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width = width * 10 + (fmt.charCodeAt(i) - 48);
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i++;
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}
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}
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// Parse precision
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let hasPrec = false;
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let prec = 0;
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if (i < len && fmt.charCodeAt(i) === 46) {
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// '.'
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hasPrec = true;
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i++;
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if (i < len && fmt.charCodeAt(i) === 42) {
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// '*'
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prec = -1;
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i++;
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} else {
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while (i < len && isDigit(fmt.charCodeAt(i))) {
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prec = prec * 10 + (fmt.charCodeAt(i) - 48);
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i++;
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}
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}
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}
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// Skip length modifiers [hlL] ignored in Lua
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while (
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i < len &&
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(fmt.charCodeAt(i) === 104 || // 'h'
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fmt.charCodeAt(i) === 108 || // 'l'
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fmt.charCodeAt(i) === 76) // 'L'
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) {
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i++;
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}
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if (i >= len) {
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throw new Error("invalid format (missing specifier)");
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}
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return {
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spec: { flags, width, hasPrec, prec, spec: fmt.charCodeAt(i) },
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end: i,
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};
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}
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// pad a string to `width` respecting `FLAG_MINUS` and `FLAG_ZERO`
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function pad(s: string, width: number, flags: number, numPad: boolean): string {
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if (width <= 0 || s.length >= width) return s;
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const n = width - s.length;
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if (numPad && flags & FLAG_ZERO && !(flags & FLAG_MINUS)) {
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let signLen = 0;
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if (s.charCodeAt(0) === 45 || s.charCodeAt(0) === 43) {
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// '-' or '+'
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signLen = 1;
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} else if (
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s.charCodeAt(0) === 48 &&
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(s.charCodeAt(1) === 120 || s.charCodeAt(1) === 88)
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) {
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signLen = 2; // '0x' or '0X'
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}
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return s.slice(0, signLen) + "0".repeat(n) + s.slice(signLen);
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}
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if (flags & FLAG_MINUS) {
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return s + " ".repeat(n);
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}
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return " ".repeat(n) + s;
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}
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function addSign(s: string, flags: number): string {
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if (flags & FLAG_PLUS) return `+${s}`;
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if (flags & FLAG_SPACE) return ` ${s}`;
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return s;
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}
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function formatInt(n: number, spec: FormatSpec): string {
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const code = spec.spec;
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const v = Math.trunc(n);
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let base = 10;
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let unsigned = false;
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let upper = false;
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switch (code) {
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case 100:
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case 105: // 'd', 'i'
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break;
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case 117: // 'u'
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unsigned = true;
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break;
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case 111: // 'o'
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base = 8;
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unsigned = true;
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break;
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case 120: // 'x'
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base = 16;
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unsigned = true;
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break;
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case 88: // 'X'
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base = 16;
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unsigned = true;
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upper = true;
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break;
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}
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let neg = false;
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let digits: string;
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if (unsigned && v < 0) {
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// Reinterpret as 64-bit unsigned
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const bv = BigInt(v) + (1n << 64n);
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digits = bv.toString(base);
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} else if (unsigned) {
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digits = v.toString(base);
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} else {
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neg = v < 0;
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digits = (neg ? -v : v).toString(base);
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}
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if (upper) digits = digits.toUpperCase();
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// Precision
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if (spec.hasPrec) {
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if (spec.prec === 0 && v === 0) {
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digits = "";
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} else if (digits.length < spec.prec) {
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digits = "0".repeat(spec.prec - digits.length) + digits;
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}
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}
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// Alt flag
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let prefix = "";
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if (spec.flags & FLAG_HASH) {
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if (base === 8 && (digits.length === 0 || digits.charCodeAt(0) !== 48)) {
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prefix = "0";
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} else if (base === 16 && v !== 0) {
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prefix = upper ? "0X" : "0x";
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}
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}
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let result: string;
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if (neg) {
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result = `-${prefix}${digits}`;
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} else {
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result = addSign(prefix + digits, spec.flags);
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}
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const numPad = !spec.hasPrec;
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return pad(result, spec.width, spec.flags, numPad);
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}
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function formatFloat(n: number, spec: FormatSpec): string {
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const code = spec.spec;
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const upper = code === 69 || code === 71 || code === 70;
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// 'E'=69 'G'=71 'F'=70 'e'=101 'g'=103 'f'=102
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const lower = code | 32; // to lowercase
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// Lua convention
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if (!Number.isFinite(n)) {
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let s: string;
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if (n !== n) {
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s = upper ? "-NAN" : "-nan";
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} else if (n > 0) {
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s = upper ? "INF" : "inf";
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s = addSign(s, spec.flags);
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} else {
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s = upper ? "-INF" : "-inf";
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}
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return pad(s, spec.width, spec.flags, false);
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}
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const neg = n < 0 || (n === 0 && 1 / n === -Infinity);
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const abs = neg ? -n : n;
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const prec = spec.hasPrec ? spec.prec : 6;
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let body: string;
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if (lower === 102) {
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// 'f'
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body = abs.toFixed(prec);
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} else if (lower === 101) {
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// 'e'
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body = abs.toExponential(prec);
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// Ensure exponent has at least 2 digits
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body = ensureExpTwoDigits(body);
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} else {
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// 'g'
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const gPrec = prec === 0 ? 1 : prec;
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if (abs === 0) {
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body = "0";
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} else {
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// C rule: use 'e' if exponent < -4 or exponent >= precision
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const exp = Math.floor(Math.log10(abs));
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if (exp < -4 || exp >= gPrec) {
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body = abs.toExponential(gPrec - 1);
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body = ensureExpTwoDigits(body);
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} else {
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// Number of decimals = precision - (exponent + 1)
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const decimals = gPrec - (exp + 1);
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body = abs.toFixed(decimals);
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}
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}
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// Strip trailing zeros unless '#' flag
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if (!(spec.flags & FLAG_HASH)) {
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body = stripTrailingZerosG(body);
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}
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}
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if (upper) {
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body = body.toUpperCase();
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}
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// Alt flag for 'f'/'e': ensure decimal point exists
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if (spec.flags & FLAG_HASH && lower !== 103) {
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if (body.indexOf(".") === -1) {
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// Insert dot before 'e' if present, else append
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const eIdx = body.indexOf("e");
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const EIdx = body.indexOf("E");
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const expIdx = eIdx !== -1 ? eIdx : EIdx;
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if (expIdx !== -1) {
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body = `${body.slice(0, expIdx)}.${body.slice(expIdx)}`;
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} else {
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body = `${body}.`;
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}
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}
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}
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// Alt flag for 'g': keep trailing zeros but ensure decimal point
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if (spec.flags & FLAG_HASH && lower === 103) {
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if (body.indexOf(".") === -1) {
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const expIdx = findExpIndex(body);
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if (expIdx !== -1) {
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body = `${body.slice(0, expIdx)}.${body.slice(expIdx)}`;
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} else {
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body = `${body}.`;
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}
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}
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}
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let result: string;
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if (neg) {
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result = `-${body}`;
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} else {
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result = addSign(body, spec.flags);
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}
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return pad(result, spec.width, spec.flags, true);
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}
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function findExpIndex(s: string): number {
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for (let i = 0; i < s.length; i++) {
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const c = s.charCodeAt(i);
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if (c === 101 || c === 69) return i; // 'e' or 'E'
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}
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return -1;
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}
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// Ensure exponent part has at least 2 digits
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function ensureExpTwoDigits(s: string): string {
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const idx = findExpIndex(s);
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if (idx === -1) return s;
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// idx+1 is sign, idx+2... are digits
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const signIdx = idx + 1;
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if (signIdx >= s.length) return s;
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const digitStart = signIdx + 1;
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const expLen = s.length - digitStart;
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if (expLen < 2) {
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return `${s.slice(0, digitStart)}0${s.slice(digitStart)}`;
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}
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return s;
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}
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// Strip trailing zeros from '%g' output
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function stripTrailingZerosG(s: string): string {
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const expIdx = findExpIndex(s);
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const mantissa = expIdx !== -1 ? s.slice(0, expIdx) : s;
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const exp = expIdx !== -1 ? s.slice(expIdx) : "";
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const dotIdx = mantissa.indexOf(".");
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if (dotIdx === -1) return s; // nothing to strip
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let end = mantissa.length;
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while (end > dotIdx + 1 && mantissa.charCodeAt(end - 1) === 48) {
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// '0'
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end--;
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}
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// Remove dot if nothing after it
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if (end === dotIdx + 1) {
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end = dotIdx;
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}
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return mantissa.slice(0, end) + exp;
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}
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// Format a number as hexadecimal floating-point (%a/%A)
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function formatHexFloat(n: number, spec: FormatSpec): string {
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const code = spec.spec;
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const upper = code === 65; // 'A'
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if (!Number.isFinite(n)) {
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let s: string;
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if (n !== n) {
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s = upper ? "-NAN" : "-nan";
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} else if (n > 0) {
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s = upper ? "INF" : "inf";
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s = addSign(s, spec.flags);
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} else {
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s = upper ? "-INF" : "-inf";
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}
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return pad(s, spec.width, spec.flags, false);
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}
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const neg = n < 0 || (n === 0 && 1 / n === -Infinity);
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const abs = neg ? -n : n;
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let body: string;
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if (abs === 0) {
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const prec = spec.hasPrec ? spec.prec : 0;
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if (prec > 0) {
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body = `0x0.${"0".repeat(prec)}p+0`;
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} else {
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body = "0x0p+0";
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}
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} else {
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body = hexFloatBody(abs, spec);
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}
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if (upper) body = body.toUpperCase();
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// Alt flag: ensure decimal point
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if (spec.flags & FLAG_HASH) {
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const pIdx = findPIndex(body);
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if (pIdx !== -1) {
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let hasDot = false;
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for (let k = 0; k < pIdx; k++) {
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if (body.charCodeAt(k) === 46) {
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// '.'
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hasDot = true;
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break;
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}
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}
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if (!hasDot) {
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body = `${body.slice(0, pIdx)}.${body.slice(pIdx)}`;
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}
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}
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}
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let result: string;
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if (neg) {
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result = `-${body}`;
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} else {
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result = addSign(body, spec.flags);
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}
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return pad(result, spec.width, spec.flags, true);
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}
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// Find index of 'p' or 'P' in hex float string
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function findPIndex(s: string): number {
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for (let i = 0; i < s.length; i++) {
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const c = s.charCodeAt(i);
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if (c === 112 || c === 80) return i; // 'p' or 'P'
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}
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return -1;
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}
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// Number of bits needed to represent a positive bigint
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function bitLength(n: bigint): number {
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let bits = 0;
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let v = n;
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while (v > 0n) {
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bits++;
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v >>= 1n;
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}
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return bits;
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}
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// Decompose a positive non-zero finite float into `0xH.HHHpN` form
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function hexFloatBody(abs: number, spec: FormatSpec): string {
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const buf = new Float64Array(1);
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const view = new DataView(buf.buffer);
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view.setFloat64(0, abs);
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const bits = view.getBigUint64(0);
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const biasedExp = Number((bits >> 52n) & 0x7ffn);
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const frac = bits & 0xfffffffffffffn;
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let exponent: number;
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let mantBits: bigint;
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if (biasedExp === 0) {
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// Subnormal
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if (frac === 0n) return "0x0p+0";
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const shift = 52 - bitLength(frac) + 1;
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mantBits = frac << BigInt(shift);
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exponent = -1022 - shift;
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} else {
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// Normal
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exponent = biasedExp - 1023;
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mantBits = frac | (1n << 52n);
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}
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let firstDigit = Number(mantBits >> 52n);
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const restBits = mantBits & ((1n << 52n) - 1n);
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// 13 hex digits from 52 bits
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let fracHex = hexDigits52(restBits);
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if (spec.hasPrec) {
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if (spec.prec < 13) {
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const carry = roundHexInPlace(fracHex, spec.prec);
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if (carry) firstDigit++;
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fracHex = truncHexDigits(fracHex, spec.prec);
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} else {
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fracHex = padHexRight(fracHex, spec.prec);
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}
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} else {
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fracHex = stripHexTrailingZeros(fracHex);
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}
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const expSign = exponent >= 0 ? "+" : "";
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if (fracHex.length > 0) {
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return `0x${firstDigit}.${fracHex}p${expSign}${exponent}`;
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}
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return `0x${firstDigit}p${expSign}${exponent}`;
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}
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// Convert 52-bit value to 13 hex digits, zero-padded
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function hexDigits52(bits: bigint): string {
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const s = bits.toString(16);
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if (s.length >= 13) return s;
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return "0".repeat(13 - s.length) + s;
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}
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// Parse one hex char to its numeric value
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function hexVal(c: number): number {
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if (c >= 48 && c <= 57) return c - 48; // '0'..'9'
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if (c >= 97 && c <= 102) return c - 87; // 'a'..'f'
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if (c >= 65 && c <= 70) return c - 55; // 'A'..'F'
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return 0;
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}
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function roundHexInPlace(digits: string, prec: number): boolean {
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if (prec >= digits.length) return false;
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const nextVal = hexVal(digits.charCodeAt(prec));
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if (nextVal < 8) return false;
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if (prec === 0) return true;
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const arr = new Array<number>(prec);
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for (let i = 0; i < prec; i++) {
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arr[i] = hexVal(digits.charCodeAt(i));
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}
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let carry = 1;
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for (let i = prec - 1; i >= 0 && carry; i--) {
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arr[i] += carry;
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if (arr[i] >= 16) {
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arr[i] = 0;
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carry = 1;
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} else {
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carry = 0;
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}
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}
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return carry === 1;
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}
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function truncHexDigits(digits: string, prec: number): string {
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if (prec === 0) return "";
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const nextVal = hexVal(digits.charCodeAt(prec));
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if (nextVal < 8) return digits.slice(0, prec);
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const arr = new Array<number>(prec);
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for (let i = 0; i < prec; i++) {
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arr[i] = hexVal(digits.charCodeAt(i));
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}
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let carry = 1;
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for (let i = prec - 1; i >= 0 && carry; i--) {
|
|
arr[i] += carry;
|
|
if (arr[i] >= 16) {
|
|
arr[i] = 0;
|
|
} else {
|
|
carry = 0;
|
|
}
|
|
}
|
|
|
|
let out = "";
|
|
for (let i = 0; i < prec; i++) {
|
|
out += arr[i].toString(16);
|
|
}
|
|
|
|
return out;
|
|
}
|
|
|
|
function padHexRight(s: string, len: number): string {
|
|
if (s.length >= len) return s;
|
|
return s + "0".repeat(len - s.length);
|
|
}
|
|
|
|
function stripHexTrailingZeros(s: string): string {
|
|
let end = s.length;
|
|
while (end > 0 && s.charCodeAt(end - 1) === 48) {
|
|
// '0'
|
|
end--;
|
|
}
|
|
if (end === s.length) return s;
|
|
return s.slice(0, end);
|
|
}
|
|
|
|
function quoteString(s: string): string {
|
|
let out = '"';
|
|
for (let i = 0; i < s.length; i++) {
|
|
const c = s.charCodeAt(i);
|
|
if (c === 34 || c === 92 || c === 10) {
|
|
// '"', '\\', '\n': backslash + literal char
|
|
out += "\\";
|
|
out += String.fromCharCode(c);
|
|
} else if (c < 32) {
|
|
const next = i + 1 < s.length ? s.charCodeAt(i + 1) : -1;
|
|
const isNextDigit = next >= 48 && next <= 57;
|
|
if (isNextDigit) {
|
|
const ds = c.toString();
|
|
out += "\\";
|
|
if (ds.length < 3) out += "0".repeat(3 - ds.length);
|
|
out += ds;
|
|
} else {
|
|
out += `\\${c.toString()}`;
|
|
}
|
|
} else {
|
|
out += String.fromCharCode(c);
|
|
}
|
|
}
|
|
out += '"';
|
|
return out;
|
|
}
|
|
|
|
// Format a float for %q: hex representation preserving full precision
|
|
function quoteFloat(n: number): string {
|
|
if (n !== n) return "(0/0)";
|
|
if (n === Infinity) return "1e9999";
|
|
if (n === -Infinity) return "-1e9999";
|
|
|
|
const spec: FormatSpec = {
|
|
flags: 0,
|
|
width: 0,
|
|
hasPrec: false,
|
|
prec: 0,
|
|
spec: 97, // 'a'
|
|
};
|
|
return formatHexFloat(n, spec);
|
|
}
|
|
|
|
function formatQ(v: unknown): string {
|
|
if (v === null || v === undefined) return "nil";
|
|
if (v === true) return "true";
|
|
if (v === false) return "false";
|
|
|
|
if (typeof v === "number") {
|
|
if (v === 0 && 1 / v === -Infinity) return quoteFloat(v);
|
|
if (Number.isInteger(v) && Number.isFinite(v)) {
|
|
return v.toString();
|
|
}
|
|
return quoteFloat(v);
|
|
}
|
|
|
|
return quoteString(String(v));
|
|
}
|
|
|
|
function formatChar(n: number): string {
|
|
return String.fromCharCode(n & 0x7f);
|
|
}
|
|
|
|
const objectIds = new WeakMap<WeakKey, number>();
|
|
const stringIds = new Map<string, number>();
|
|
let nextId = 1;
|
|
|
|
function toPointer(v: unknown): string {
|
|
if (v === null || v === undefined) return "(null)";
|
|
if (typeof v === "boolean" || typeof v === "number") return "(null)";
|
|
|
|
// Primitives (strings, symbols, etc.) cannot be `WeakMap` keys
|
|
if (typeof v !== "object" && typeof v !== "function") {
|
|
const key = String(v);
|
|
let id = stringIds.get(key);
|
|
if (id === undefined) {
|
|
id = nextId++;
|
|
stringIds.set(key, id);
|
|
}
|
|
return `0x${id.toString(16).padStart(14, "0")}`;
|
|
}
|
|
|
|
const obj = v as object;
|
|
let id = objectIds.get(obj);
|
|
if (id === undefined) {
|
|
id = nextId++;
|
|
objectIds.set(obj, id);
|
|
}
|
|
return `0x${id.toString(16).padStart(14, "0")}`;
|
|
}
|
|
|
|
function formatPointer(v: unknown, spec: FormatSpec): string {
|
|
const s = toPointer(v);
|
|
// `%p` only supports width and '-' flag, no precision
|
|
return pad(s, spec.width, spec.flags, false);
|
|
}
|
|
|
|
export function luaFormat(fmt: string, ...args: any[]): string {
|
|
let out = "";
|
|
let ai = 0; // arg index
|
|
const len = fmt.length;
|
|
let i = 0;
|
|
|
|
while (i < len) {
|
|
const c = fmt.charCodeAt(i);
|
|
if (c !== 37) {
|
|
// not '%'
|
|
// Fast path: scan for next '%' or end
|
|
let j = i + 1;
|
|
while (j < len && fmt.charCodeAt(j) !== 37) j++;
|
|
out += fmt.slice(i, j);
|
|
i = j;
|
|
continue;
|
|
}
|
|
|
|
// '%' found
|
|
i++;
|
|
if (i >= len) {
|
|
throw new Error("invalid format (ends with '%')");
|
|
}
|
|
|
|
// '%%' into literal '%'
|
|
if (fmt.charCodeAt(i) === 37) {
|
|
out += "%";
|
|
i++;
|
|
continue;
|
|
}
|
|
|
|
const { spec, end } = parseSpec(fmt, i);
|
|
i = end + 1;
|
|
|
|
// Resolve `*` width and precision from args
|
|
let width = spec.width;
|
|
if (width === -1) {
|
|
width = Number(args[ai++]) || 0;
|
|
if (width < 0) {
|
|
spec.flags |= FLAG_MINUS;
|
|
width = -width;
|
|
}
|
|
spec.width = width;
|
|
}
|
|
if (spec.prec === -1) {
|
|
let p = Number(args[ai++]) || 0;
|
|
if (p < 0) {
|
|
spec.hasPrec = false;
|
|
p = 0;
|
|
}
|
|
spec.prec = p;
|
|
}
|
|
|
|
const code = spec.spec;
|
|
switch (code) {
|
|
case 97:
|
|
case 65: // 'a', 'A'
|
|
out += formatHexFloat(Number(args[ai++]), spec);
|
|
break;
|
|
case 100:
|
|
case 105:
|
|
case 117: // 'd', 'i', 'u'
|
|
case 111:
|
|
case 120:
|
|
case 88: // 'o', 'x', 'X'
|
|
out += formatInt(Number(args[ai++]), spec);
|
|
break;
|
|
case 102:
|
|
case 101:
|
|
case 69: // 'f', 'e', 'E'
|
|
case 103:
|
|
case 71:
|
|
case 70: // 'g', 'G', 'F'
|
|
out += formatFloat(Number(args[ai++]), spec);
|
|
break;
|
|
case 99: // 'c'
|
|
out += pad(
|
|
formatChar(Number(args[ai++])),
|
|
spec.width,
|
|
spec.flags,
|
|
false,
|
|
);
|
|
break;
|
|
case 112: {
|
|
// 'p'
|
|
out += formatPointer(args[ai++], spec);
|
|
break;
|
|
}
|
|
case 113: {
|
|
// 'q'
|
|
out += formatQ(args[ai++]);
|
|
break;
|
|
}
|
|
case 115: {
|
|
// 's'
|
|
let s = String(args[ai++]);
|
|
if (spec.hasPrec && s.length > spec.prec) {
|
|
s = s.slice(0, spec.prec);
|
|
}
|
|
out += pad(s, spec.width, spec.flags, false);
|
|
break;
|
|
}
|
|
default:
|
|
throw new Error(
|
|
`invalid format specifier '${String.fromCharCode(code)}'`,
|
|
);
|
|
}
|
|
}
|
|
|
|
return out;
|
|
}
|