160 lines
4.4 KiB
TypeScript
160 lines
4.4 KiB
TypeScript
import MarkdownIt, {StateInline, Token} from 'markdown-it';
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/**
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* 分隔符接口定义
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*/
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interface Delimiter {
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marker: number;
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length: number;
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jump: number;
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token: number;
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end: number;
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open: boolean;
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close: boolean;
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}
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/**
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* 扫描结果接口定义
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*/
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interface ScanResult {
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can_open: boolean;
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can_close: boolean;
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length: number;
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}
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/**
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* Token 元数据接口定义
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*/
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interface TokenMeta {
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delimiters?: Delimiter[];
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}
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/**
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* markdown-it-mark 插件
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* 用于支持 ==标记文本== 语法
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*/
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export default function markPlugin(md: MarkdownIt): void {
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// Insert each marker as a separate text token, and add it to delimiter list
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//
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function tokenize(state: StateInline, silent: boolean): boolean {
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const start = state.pos;
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const marker = state.src.charCodeAt(start);
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if (silent) { return false; }
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if (marker !== 0x3D/* = */) { return false; }
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const scanned = state.scanDelims(state.pos, true) as ScanResult;
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let len = scanned.length;
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const ch = String.fromCharCode(marker);
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if (len < 2) { return false; }
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if (len % 2) {
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const token: Token = state.push('text', '', 0);
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token.content = ch;
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len--;
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}
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for (let i = 0; i < len; i += 2) {
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const token: Token = state.push('text', '', 0);
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token.content = ch + ch;
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if (!scanned.can_open && !scanned.can_close) { continue; }
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state.delimiters.push({
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marker,
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length: 0, // disable "rule of 3" length checks meant for emphasis
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jump: i / 2, // 1 delimiter = 2 characters
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token: state.tokens.length - 1,
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end: -1,
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open: scanned.can_open,
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close: scanned.can_close
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} as Delimiter);
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}
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state.pos += scanned.length;
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return true;
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}
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// Walk through delimiter list and replace text tokens with tags
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//
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function postProcess(state: StateInline, delimiters: Delimiter[]): void {
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const loneMarkers: number[] = [];
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const max = delimiters.length;
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for (let i = 0; i < max; i++) {
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const startDelim = delimiters[i];
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if (startDelim.marker !== 0x3D/* = */) {
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continue;
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}
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if (startDelim.end === -1) {
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continue;
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}
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const endDelim = delimiters[startDelim.end];
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const token_o = state.tokens[startDelim.token];
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token_o.type = 'mark_open';
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token_o.tag = 'mark';
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token_o.nesting = 1;
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token_o.markup = '==';
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token_o.content = '';
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const token_c = state.tokens[endDelim.token];
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token_c.type = 'mark_close';
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token_c.tag = 'mark';
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token_c.nesting = -1;
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token_c.markup = '==';
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token_c.content = '';
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if (state.tokens[endDelim.token - 1].type === 'text' &&
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state.tokens[endDelim.token - 1].content === '=') {
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loneMarkers.push(endDelim.token - 1);
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}
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}
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// If a marker sequence has an odd number of characters, it's splitted
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// like this: `~~~~~` -> `~` + `~~` + `~~`, leaving one marker at the
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// start of the sequence.
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//
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// So, we have to move all those markers after subsequent s_close tags.
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//
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while (loneMarkers.length) {
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const i = loneMarkers.pop()!;
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let j = i + 1;
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while (j < state.tokens.length && state.tokens[j].type === 'mark_close') {
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j++;
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}
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j--;
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if (i !== j) {
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const token = state.tokens[j];
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state.tokens[j] = state.tokens[i];
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state.tokens[i] = token;
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}
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}
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}
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md.inline.ruler.before('emphasis', 'mark', tokenize);
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md.inline.ruler2.before('emphasis', 'mark', function (state: StateInline): boolean {
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let curr: number;
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const tokens_meta = state.tokens_meta as TokenMeta[];
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const max = (state.tokens_meta || []).length;
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postProcess(state, state.delimiters as Delimiter[]);
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for (curr = 0; curr < max; curr++) {
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if (tokens_meta[curr] && tokens_meta[curr].delimiters) {
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postProcess(state, tokens_meta[curr].delimiters!);
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}
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}
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return true;
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});
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} |