danielyaa5/mdparser.js

## mdparser.js
const getTag = (text, [lastParsedTag, lastParsedText] = [null, null]) => {
	if (text.length === 0) return null;

	const listItem = text[0] === '-';
	if (listItem) return 'li';

	const hashes = text.match(/^#+/);
	if (hashes) return `h${Math.min(6, hashes[0].length)}`;

	if (lastParsedTag === 'p' || lastParsedTag === 'li') return 'continued';

	return 'p';
};

const clean = (text, tag) => {
	if (tag && tag[0] === 'h') return text.substring(tag[1]).trim();
	return text.replace(/^-\s*/, '');
}

const isContinuedTag = tag => tag.includes('continued-');

const wrapHtml = body => `<html>\n<body>\n${body}</body>\n</html>`;

const toHtml = parsedLines => parsedLines.reduce((acc, [currTag, currText], i) => {
	const [lastTag, lastText] = i > 0 ? parsedLines[i - 1] : [null, null];

	if (currTag === 'li' && lastTag !== 'li') {
		acc += '<ul>\n'
	}

	if (currTag) {
		acc += `<${currTag}>${clean(currText, currTag)}</${currTag}>\n`;
	}

	if (currTag === null && lastTag === 'li') {
		acc += '</ul>\n'
	}

	return acc;
}, '');

const parse = md => md.split('\n').reduce((acc, line, i, src) => {
	const text = line.trim();
	const lastParsedLine = i > 0 ? acc[acc.length - 1] : [null, null];
	const [lastParsedTag, lastParsedText] = lastParsedLine;
	const lineTag = getTag(text, lastParsedLine);

	if (lineTag === 'continued') {
		lastParsedLine[1] = `${lastParsedText} ${text}`;
	} else if (lineTag === null && lastParsedTag !== null) {
		acc.push([null, null]);
	} else {
		acc.push([lineTag, text]);
	}

	const isLastLine = i === src.length - 1;
	if (isLastLine) return wrapHtml(toHtml(acc));

	return acc;
}, []);

const test = `
# hello, This is Markdown Live Preview

## what is Markdown?


## usage

## markdown quick reference
# headers

- hey
- adofasdkfjadsjfasdklflsdajf
jfasdkflsajdfklsadjfasdf
- fasdfasd

hello im a paragraph
on mulitple lines

heres a new paragraph
`;

console.log(parse(test));
	const getTag = (text, [lastParsedTag, lastParsedText] = [null, null]) => {
	if (text.length === 0) return null;

	const listItem = text[0] === '-';
	if (listItem) return 'li';

	const hashes = text.match(/^#+/);
	if (hashes) return `h${Math.min(6, hashes[0].length)}`;

	if (lastParsedTag === 'p' \|\| lastParsedTag === 'li') return 'continued';

	return 'p';
	};

	const clean = (text, tag) => {
	if (tag && tag[0] === 'h') return text.substring(tag[1]).trim();
	return text.replace(/^-\s*/, '');
	}

	const isContinuedTag = tag => tag.includes('continued-');

	const wrapHtml = body => `<html>\n<body>\n${body}</body>\n</html>`;

	const toHtml = parsedLines => parsedLines.reduce((acc, [currTag, currText], i) => {
	const [lastTag, lastText] = i > 0 ? parsedLines[i - 1] : [null, null];

	if (currTag === 'li' && lastTag !== 'li') {
	acc += '<ul>\n'
	}

	if (currTag) {
	acc += `<${currTag}>${clean(currText, currTag)}</${currTag}>\n`;
	}

	if (currTag === null && lastTag === 'li') {
	acc += '</ul>\n'
	}

	return acc;
	}, '');

	const parse = md => md.split('\n').reduce((acc, line, i, src) => {
	const text = line.trim();
	const lastParsedLine = i > 0 ? acc[acc.length - 1] : [null, null];
	const [lastParsedTag, lastParsedText] = lastParsedLine;
	const lineTag = getTag(text, lastParsedLine);

	if (lineTag === 'continued') {
	lastParsedLine[1] = `${lastParsedText} ${text}`;
	} else if (lineTag === null && lastParsedTag !== null) {
	acc.push([null, null]);
	} else {
	acc.push([lineTag, text]);
	}

	const isLastLine = i === src.length - 1;
	if (isLastLine) return wrapHtml(toHtml(acc));

	return acc;
	}, []);

	const test = `
	# hello, This is Markdown Live Preview

	## what is Markdown?


	## usage

	## markdown quick reference
	# headers

	- hey
	- adofasdkfjadsjfasdklflsdajf
	jfasdkflsajdfklsadjfasdf
	- fasdfasd

	hello im a paragraph
	on mulitple lines

	heres a new paragraph
	`;

	console.log(parse(test));