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- 'use strict';
- const stringify = require('./stringify');
- /**
- * Constants
- */
- const {
- MAX_LENGTH,
- CHAR_BACKSLASH, /* \ */
- CHAR_BACKTICK, /* ` */
- CHAR_COMMA, /* , */
- CHAR_DOT, /* . */
- CHAR_LEFT_PARENTHESES, /* ( */
- CHAR_RIGHT_PARENTHESES, /* ) */
- CHAR_LEFT_CURLY_BRACE, /* { */
- CHAR_RIGHT_CURLY_BRACE, /* } */
- CHAR_LEFT_SQUARE_BRACKET, /* [ */
- CHAR_RIGHT_SQUARE_BRACKET, /* ] */
- CHAR_DOUBLE_QUOTE, /* " */
- CHAR_SINGLE_QUOTE, /* ' */
- CHAR_NO_BREAK_SPACE,
- CHAR_ZERO_WIDTH_NOBREAK_SPACE
- } = require('./constants');
- /**
- * parse
- */
- const parse = (input, options = {}) => {
- if (typeof input !== 'string') {
- throw new TypeError('Expected a string');
- }
- const opts = options || {};
- const max = typeof opts.maxLength === 'number' ? Math.min(MAX_LENGTH, opts.maxLength) : MAX_LENGTH;
- if (input.length > max) {
- throw new SyntaxError(`Input length (${input.length}), exceeds max characters (${max})`);
- }
- const ast = { type: 'root', input, nodes: [] };
- const stack = [ast];
- let block = ast;
- let prev = ast;
- let brackets = 0;
- const length = input.length;
- let index = 0;
- let depth = 0;
- let value;
- /**
- * Helpers
- */
- const advance = () => input[index++];
- const push = node => {
- if (node.type === 'text' && prev.type === 'dot') {
- prev.type = 'text';
- }
- if (prev && prev.type === 'text' && node.type === 'text') {
- prev.value += node.value;
- return;
- }
- block.nodes.push(node);
- node.parent = block;
- node.prev = prev;
- prev = node;
- return node;
- };
- push({ type: 'bos' });
- while (index < length) {
- block = stack[stack.length - 1];
- value = advance();
- /**
- * Invalid chars
- */
- if (value === CHAR_ZERO_WIDTH_NOBREAK_SPACE || value === CHAR_NO_BREAK_SPACE) {
- continue;
- }
- /**
- * Escaped chars
- */
- if (value === CHAR_BACKSLASH) {
- push({ type: 'text', value: (options.keepEscaping ? value : '') + advance() });
- continue;
- }
- /**
- * Right square bracket (literal): ']'
- */
- if (value === CHAR_RIGHT_SQUARE_BRACKET) {
- push({ type: 'text', value: '\\' + value });
- continue;
- }
- /**
- * Left square bracket: '['
- */
- if (value === CHAR_LEFT_SQUARE_BRACKET) {
- brackets++;
- let next;
- while (index < length && (next = advance())) {
- value += next;
- if (next === CHAR_LEFT_SQUARE_BRACKET) {
- brackets++;
- continue;
- }
- if (next === CHAR_BACKSLASH) {
- value += advance();
- continue;
- }
- if (next === CHAR_RIGHT_SQUARE_BRACKET) {
- brackets--;
- if (brackets === 0) {
- break;
- }
- }
- }
- push({ type: 'text', value });
- continue;
- }
- /**
- * Parentheses
- */
- if (value === CHAR_LEFT_PARENTHESES) {
- block = push({ type: 'paren', nodes: [] });
- stack.push(block);
- push({ type: 'text', value });
- continue;
- }
- if (value === CHAR_RIGHT_PARENTHESES) {
- if (block.type !== 'paren') {
- push({ type: 'text', value });
- continue;
- }
- block = stack.pop();
- push({ type: 'text', value });
- block = stack[stack.length - 1];
- continue;
- }
- /**
- * Quotes: '|"|`
- */
- if (value === CHAR_DOUBLE_QUOTE || value === CHAR_SINGLE_QUOTE || value === CHAR_BACKTICK) {
- const open = value;
- let next;
- if (options.keepQuotes !== true) {
- value = '';
- }
- while (index < length && (next = advance())) {
- if (next === CHAR_BACKSLASH) {
- value += next + advance();
- continue;
- }
- if (next === open) {
- if (options.keepQuotes === true) value += next;
- break;
- }
- value += next;
- }
- push({ type: 'text', value });
- continue;
- }
- /**
- * Left curly brace: '{'
- */
- if (value === CHAR_LEFT_CURLY_BRACE) {
- depth++;
- const dollar = prev.value && prev.value.slice(-1) === '$' || block.dollar === true;
- const brace = {
- type: 'brace',
- open: true,
- close: false,
- dollar,
- depth,
- commas: 0,
- ranges: 0,
- nodes: []
- };
- block = push(brace);
- stack.push(block);
- push({ type: 'open', value });
- continue;
- }
- /**
- * Right curly brace: '}'
- */
- if (value === CHAR_RIGHT_CURLY_BRACE) {
- if (block.type !== 'brace') {
- push({ type: 'text', value });
- continue;
- }
- const type = 'close';
- block = stack.pop();
- block.close = true;
- push({ type, value });
- depth--;
- block = stack[stack.length - 1];
- continue;
- }
- /**
- * Comma: ','
- */
- if (value === CHAR_COMMA && depth > 0) {
- if (block.ranges > 0) {
- block.ranges = 0;
- const open = block.nodes.shift();
- block.nodes = [open, { type: 'text', value: stringify(block) }];
- }
- push({ type: 'comma', value });
- block.commas++;
- continue;
- }
- /**
- * Dot: '.'
- */
- if (value === CHAR_DOT && depth > 0 && block.commas === 0) {
- const siblings = block.nodes;
- if (depth === 0 || siblings.length === 0) {
- push({ type: 'text', value });
- continue;
- }
- if (prev.type === 'dot') {
- block.range = [];
- prev.value += value;
- prev.type = 'range';
- if (block.nodes.length !== 3 && block.nodes.length !== 5) {
- block.invalid = true;
- block.ranges = 0;
- prev.type = 'text';
- continue;
- }
- block.ranges++;
- block.args = [];
- continue;
- }
- if (prev.type === 'range') {
- siblings.pop();
- const before = siblings[siblings.length - 1];
- before.value += prev.value + value;
- prev = before;
- block.ranges--;
- continue;
- }
- push({ type: 'dot', value });
- continue;
- }
- /**
- * Text
- */
- push({ type: 'text', value });
- }
- // Mark imbalanced braces and brackets as invalid
- do {
- block = stack.pop();
- if (block.type !== 'root') {
- block.nodes.forEach(node => {
- if (!node.nodes) {
- if (node.type === 'open') node.isOpen = true;
- if (node.type === 'close') node.isClose = true;
- if (!node.nodes) node.type = 'text';
- node.invalid = true;
- }
- });
- // get the location of the block on parent.nodes (block's siblings)
- const parent = stack[stack.length - 1];
- const index = parent.nodes.indexOf(block);
- // replace the (invalid) block with it's nodes
- parent.nodes.splice(index, 1, ...block.nodes);
- }
- } while (stack.length > 0);
- push({ type: 'eos' });
- return ast;
- };
- module.exports = parse;
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