hexo/node_modules/strip-comments/lib/parse.js

142 lines
3.5 KiB
JavaScript

'use strict';
const { Node, Block } = require('./Node');
const languages = require('./languages');
const constants = {
ESCAPED_CHAR_REGEX: /^\\./,
QUOTED_STRING_REGEX: /^(['"`])((?:\\.|[^\1])+?)(\1)/,
NEWLINE_REGEX: /^\r*\n/
};
const parse = (input, options = {}) => {
if (typeof input !== 'string') {
throw new TypeError('Expected input to be a string');
}
const cst = new Block({ type: 'root', nodes: [] });
const stack = [cst];
const name = (options.language || 'javascript').toLowerCase();
const lang = languages[name];
if (typeof lang === 'undefined') {
throw new Error(`Language "${name}" is not supported by strip-comments`);
}
const { LINE_REGEX, BLOCK_OPEN_REGEX, BLOCK_CLOSE_REGEX } = lang;
let block = cst;
let remaining = input;
let token;
let prev;
const source = [BLOCK_OPEN_REGEX, BLOCK_CLOSE_REGEX].filter(Boolean);
let tripleQuotes = false;
if (source.every(regex => regex.source === '^"""')) {
tripleQuotes = true;
}
/**
* Helpers
*/
const consume = (value = remaining[0] || '') => {
remaining = remaining.slice(value.length);
return value;
};
const scan = (regex, type = 'text') => {
const match = regex.exec(remaining);
if (match) {
consume(match[0]);
return { type, value: match[0], match };
}
};
const push = node => {
if (prev && prev.type === 'text' && node.type === 'text') {
prev.value += node.value;
return;
}
block.push(node);
if (node.nodes) {
stack.push(node);
block = node;
}
prev = node;
};
const pop = () => {
if (block.type === 'root') {
throw new SyntaxError('Unclosed block comment');
}
stack.pop();
block = stack[stack.length - 1];
};
/**
* Parse input string
*/
while (remaining !== '') {
// escaped characters
if ((token = scan(constants.ESCAPED_CHAR_REGEX, 'text'))) {
push(new Node(token));
continue;
}
// quoted strings
if (block.type !== 'block' && (!prev || !/\w$/.test(prev.value)) && !(tripleQuotes && remaining.startsWith('"""'))) {
if ((token = scan(constants.QUOTED_STRING_REGEX, 'text'))) {
push(new Node(token));
continue;
}
}
// newlines
if ((token = scan(constants.NEWLINE_REGEX, 'newline'))) {
push(new Node(token));
continue;
}
// block comment open
if (BLOCK_OPEN_REGEX && options.block && !(tripleQuotes && block.type === 'block')) {
if ((token = scan(BLOCK_OPEN_REGEX, 'open'))) {
push(new Block({ type: 'block' }));
push(new Node(token));
continue;
}
}
// block comment close
if (BLOCK_CLOSE_REGEX && block.type === 'block' && options.block) {
if ((token = scan(BLOCK_CLOSE_REGEX, 'close'))) {
token.newline = token.match[1] || '';
push(new Node(token));
pop();
continue;
}
}
// line comment
if (LINE_REGEX && block.type !== 'block' && options.line) {
if ((token = scan(LINE_REGEX, 'line'))) {
push(new Node(token));
continue;
}
}
// Plain text (skip "C" since some languages use "C" to start comments)
if ((token = scan(/^[a-zABD-Z0-9\t ]+/, 'text'))) {
push(new Node(token));
continue;
}
push(new Node({ type: 'text', value: consume(remaining[0]) }));
}
return cst;
};
module.exports = parse;