Improve MFM bracket matching

Co-authored-by: syuilo <syuilotan@yahoo.co.jp>
This commit is contained in:
Aya Morisawa 2018-12-22 00:41:54 +09:00
parent be0cb88b6c
commit 580191fb17
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GPG Key ID: 3E64865D70D579F2
3 changed files with 115 additions and 28 deletions

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@ -1,7 +1,7 @@
import * as P from 'parsimmon';
import parseAcct from '../misc/acct/parse';
import { toUnicode } from 'punycode';
import { takeWhile } from '../prelude/array';
import { takeWhile, cumulativeSum } from '../prelude/array';
import { Tree } from '../prelude/tree';
import * as T from '../prelude/tree';
@ -42,30 +42,18 @@ export function createTree(type: string, children: MfmForest, props: any): MfmTr
return T.createTree({ type, props }, children);
}
function getTrailingPosition(x: string): number {
const brackets = [
['(', ')'],
['「', '」'],
];
const pendingBrackets = [] as any;
const end = x.split('').findIndex(char => {
const closeMatch = brackets.map(x => x[1]).indexOf(char);
const openMatch = brackets.map(x => x[0]).indexOf(char);
if (closeMatch != -1) {
if (pendingBrackets[closeMatch] > 0) {
pendingBrackets[closeMatch]--;
return false;
} else {
return true;
}
} else if (openMatch != -1) {
pendingBrackets[openMatch] = (pendingBrackets[openMatch] || 0) + 1;
return false;
} else {
return false;
}
});
return end > 0 ? end : x.length;
export function removeOrphanedBrackets(s: string): string {
const openBrackets = ['(', '「'];
const closeBrackets = [')', '」'];
const xs = cumulativeSum(s.split('').map(c => {
if (openBrackets.includes(c)) return 1;
if (closeBrackets.includes(c)) return -1;
return 0;
}));
const firstOrphanedCloseBracket = xs.findIndex(x => x < 0);
if (firstOrphanedCloseBracket !== -1) return s.substr(0, firstOrphanedCloseBracket);
const lastMatched = xs.lastIndexOf(0);
return s.substr(0, lastMatched + 1);
}
const newline = P((input, i) => {
@ -220,7 +208,7 @@ const mfm = P.createLanguage({
const match = text.match(/^#([^\s\.,!\?#]+)/i);
if (!match) return P.makeFailure(i, 'not a hashtag');
let hashtag = match[1];
hashtag = hashtag.substr(0, getTrailingPosition(hashtag));
hashtag = removeOrphanedBrackets(hashtag);
if (hashtag.match(/^[0-9]+$/)) return P.makeFailure(i, 'not a hashtag');
if (input[i - 1] != null && input[i - 1].match(/[a-z0-9]/i)) return P.makeFailure(i, 'not a hashtag');
if (hashtag.length > 50) return P.makeFailure(i, 'not a hashtag');
@ -390,7 +378,7 @@ const mfm = P.createLanguage({
const match = text.match(/^https?:\/\/[\w\/:%#@\$&\?!\(\)\[\]~\.,=\+\-]+/);
if (!match) return P.makeFailure(i, 'not a url');
let url = match[0];
url = url.substr(0, getTrailingPosition(url));
url = removeOrphanedBrackets(url);
if (url.endsWith('.')) url = url.substr(0, url.lastIndexOf('.'));
if (url.endsWith(',')) url = url.substr(0, url.lastIndexOf(','));
return P.makeSuccess(i + url.length, url);

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@ -109,3 +109,9 @@ export function takeWhile<T>(f: Predicate<T>, xs: T[]): T[] {
}
return ys;
}
export function cumulativeSum(xs: number[]): number[] {
const ys = Array.from(xs); // deep copy
for (let i = 1; i < ys.length; i++) ys[i] += ys[i - 1];
return ys;
}

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@ -6,7 +6,7 @@ import * as assert from 'assert';
import analyze from '../src/mfm/parse';
import toHtml from '../src/mfm/html';
import { createTree as tree, createLeaf as leaf, MfmTree } from '../src/mfm/parser';
import { createTree as tree, createLeaf as leaf, MfmTree, removeOrphanedBrackets } from '../src/mfm/parser';
function text(text: string): MfmTree {
return leaf('text', { text });
@ -49,6 +49,99 @@ describe('createTree', () => {
});
});
describe('removeOrphanedBrackets', () => {
it('single (contained)', () => {
const input = '(foo)';
const expected = '(foo)';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('single (head)', () => {
const input = '(foo)bar';
const expected = '(foo)bar';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('single (tail)', () => {
const input = 'foo(bar)';
const expected = 'foo(bar)';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('a', () => {
const input = '(foo';
const expected = '';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('b', () => {
const input = ')foo';
const expected = '';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('nested', () => {
const input = 'foo(「(bar)」)';
const expected = 'foo(「(bar)」)';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('no brackets', () => {
const input = 'foo';
const expected = 'foo';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('with foreign bracket (single)', () => {
const input = 'foo(bar))';
const expected = 'foo(bar)';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('with foreign bracket (open)', () => {
const input = 'foo(bar';
const expected = 'foo';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('with foreign bracket (close)', () => {
const input = 'foo)bar';
const expected = 'foo';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('with foreign bracket (close and open)', () => {
const input = 'foo)(bar';
const expected = 'foo';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('various bracket type', () => {
const input = 'foo「(bar)」(';
const expected = 'foo「(bar)」';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
it('intersected', () => {
const input = 'foo(「)」';
const expected = 'foo(「)」';
const actual = removeOrphanedBrackets(input);
assert.deepStrictEqual(actual, expected);
});
});
describe('MFM', () => {
it('can be analyzed', () => {
const tokens = analyze('@himawari @hima_sub@namori.net お腹ペコい :cat: #yryr');