Mirror: The magical sticky regex-based parser generator 🧙
Golf some bytes off of parser
+17
-26
+17
-26
src/parser.js
+17
-26
src/parser.js
···
1
+
const syntaxError = (char) => {
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throw new SyntaxError('Unexpected token "' + char + '"');
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};
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+
1
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export const parse = (quasis, expressions) => {
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let quasiIndex = 0;
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let stackIndex = 0;
···
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let lastMatch;
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let currentSequence = rootSequence;
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12
-
while (stackIndex < quasis.length + expressions.length) {
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for (
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let quasiIndex = 0, stackIndex = 0;
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stackIndex < quasis.length + expressions.length;
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stackIndex++
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) {
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if (stackIndex % 2 !== 0) {
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currentSequence.push({
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expression: expressions[stackIndex++ >> 1],
···
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}
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const quasi = quasis[stackIndex >> 1];
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while (quasiIndex < quasi.length) {
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for (quasiIndex = 0; quasiIndex < quasi.length; ) {
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const char = quasi[quasiIndex++];
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-
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if (char === ' ' || char === '\t' || char === '\r' || char === '\n') {
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continue;
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} else if (char === '|' && currentSequence.length) {
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currentSequence = currentSequence.alternation = [];
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continue;
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} else if (char === ')' && currentSequence.length) {
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currentGroup = null;
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currentSequence = sequenceStack.pop();
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if (currentSequence) continue;
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if (!currentSequence) syntaxError(char);
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} else if (char === '(') {
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currentGroup = {
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sequence: [],
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};
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sequenceStack.push(currentSequence);
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currentSequence.push(currentGroup);
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currentSequence.push((currentGroup = { sequence: [] }));
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currentSequence = currentGroup.sequence;
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continue;
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} else if (char === '?' && !currentSequence.length && currentGroup) {
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const nextChar = quasi[quasiIndex++];
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if (nextChar === ':') {
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if (nextChar === ':' || nextChar === '=' || nextChar === '!') {
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currentGroup.capture = nextChar;
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continue;
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} else if (nextChar === '=') {
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currentGroup.capture = nextChar;
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continue;
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} else if (nextChar === '!') {
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currentGroup.capture = nextChar;
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-
continue;
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} else {
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syntaxError(char);
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}
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} else if (
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(char === '?' || char === '+' || char === '*') &&
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(lastMatch = currentSequence[currentSequence.length - 1])
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) {
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lastMatch.quantifier = char;
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-
continue;
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} else {
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syntaxError(char);
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}
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-
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throw new SyntaxError('Unexpected token "' + char + '"');
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}
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stackIndex++;
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quasiIndex = 0;
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}
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return rootSequence;