Markdown — Hive

function wrap(text, tag) {return `<${tag}>${text}</${tag}>`;}

function isTag(text, tag) {return text.startsWith(`<${tag}>`);}

function parser(markdown, delimiter, tag) {return markdown.replace(new RegExp(`${delimiter}(.+)${delimiter}`), `<${tag}>$1</${tag}>`);}

function parse__(markdown) {return parser(markdown, '__', 'strong');}

function parse_(markdown) {return parser(markdown, '_', 'em');}

function parseText(markdown, list) {if (list) {return parse_(parse__(markdown));} else {return wrap(parse_(parse__(markdown)), 'p');}}

function parseHeader(markdown, list) {

let count = 0;

for (let i = 0; i < markdown.length; i++) {

if(markdown[i] === '#'){count += 1;} 

else {break;}

}

if (count === 0 || count > 6) {return [null, list]; }

const headerHtml = wrap(markdown.substring(count + 1), `h${count}`);

return list? [`${headerHtml}`, false]: [headerHtml, false];

}

function parseLineItem(markdown, list) {

if (markdown.startsWith('*')) {

const innerHtml = wrap(parseText(markdown.substring(2), true), 'li');

return (list) ? [innerHtml, true]:[\`<ul>${innerHtml}\`, true];

}

return [null, list];

}

function parseParagraph(markdown, list) {return (!list)? [parseText(markdown, false), false]: [`${parseText(markdown, false)}`, false];}

function parseLine(markdown, list) {

let [result, inListAfter] = parseHeader(markdown, list);

if (result === null) {[result, inListAfter] = parseLineItem(markdown, list);}

if (result === null) {[result, inListAfter] = parseParagraph(markdown, list);}

if(result === null) {throw new Error('Invalid markdown');}

return [result, inListAfter];

}

export function parse(markdown) {

const lines = markdown.split('\n');

let result = '';

let list = false;

for (let i = 0; i < lines.length; i++) {

let [lineResult, newList] = parseLine(lines[i], list);

result += lineResult;

list = newList;

}

return (list)? result + '': result;

}