| 1 | | function wrap(text, tag) { |
| 2 | | return `<${tag}>${text}</${tag}>`; |
| 3 | | } |
| 4 | | |
| 5 | | function isTag(text, tag) { |
| 6 | | return text.startsWith(`<${tag}>`); |
| 7 | | } |
| 8 | | |
| 9 | | function parser(markdown, delimiter, tag) { |
| 10 | | const pattern = new RegExp(`${delimiter}(.+)${delimiter}`); |
| 11 | | const replacement = `<${tag}>$1</${tag}>`; |
| 12 | | return markdown.replace(pattern, replacement); |
| 13 | | } |
| 14 | | |
| 15 | | function parse__(markdown) { |
| 16 | | return parser(markdown, '__', 'strong'); |
| 17 | | } |
| 18 | | |
| 19 | | function parse_(markdown) { |
| 20 | | return parser(markdown, '_', 'em'); |
| 21 | | } |
| 22 | | |
| 23 | | function parseText(markdown, list) { |
| 24 | | const parsedText = parse_(parse__(markdown)); |
| 25 | | if (list) { |
| 26 | | return parsedText; |
| 27 | | } else { |
| 28 | | return wrap(parsedText, 'p'); |
| 1 | /** |
| 2 | * A Markdown parser that converts Markdown syntax to HTML |
| 3 | * Refactored for better readability and maintainability |
| 4 | */ |
| 5 | class MarkdownParser { |
| 6 | /** |
| 7 | * Parse inline formatting (__ for strong, _ for emphasis) |
| 8 | * @param {string} text - Text to parse |
| 9 | * @returns {string} - Text with inline formatting converted to HTML |
| 10 | */ |
| 11 | parseInlineFormatting(text) { |
| 12 | // Parse strong (__text__) |
| 13 | text = text.replace(/__(.+)__/g, '<strong>$1</strong>'); |
| 14 | // Parse emphasis (_text_) |
| 15 | text = text.replace(/_(.+)_/g, '<em>$1</em>'); |
| 16 | return text; |
| 29 | 17 | } |
| 30 | | } |
| 31 | 18 | |
| 32 | | function parseHeader(markdown, list) { |
| 33 | | let count = 0; |
| 34 | | for (let i = 0; i < markdown.length; i++) { |
| 35 | | if (markdown[i] === '#') { |
| 36 | | count += 1; |
| 37 | | } else { |
| 38 | | break; |
| 39 | | } |
| 40 | | } |
| 41 | | if (count === 0 || count > 6) { |
| 42 | | return [null, list]; |
| 19 | /** |
| 20 | * Parse a header (# Header -> <h1>Header</h1>) |
| 21 | * @param {string} line - Line to parse |
| 22 | * @returns {string|null} - HTML header or null if not a header |
| 23 | */ |
| 24 | parseHeader(line) { |
| 25 | const headerMatch = line.match(/^(#{1,6})\s+(.+)$/); |
| 26 | if (!headerMatch) return null; |
| 27 | |
| 28 | const level = headerMatch[1].length; |
| 29 | const content = this.parseInlineFormatting(headerMatch[2]); |
| 30 | return `<h${level}>${content}</h${level}>`; |
| 43 | 31 | } |
| 44 | | const headerTag = `h${count}`; |
| 45 | | const headerHtml = wrap(markdown.substring(count + 1), headerTag); |
| 46 | | if (list) { |
| 47 | | return [`</ul>${headerHtml}`, false]; |
| 48 | | } else { |
| 49 | | return [headerHtml, false]; |
| 50 | | } |
| 51 | | } |
| 52 | 32 | |
| 53 | | function parseLineItem(markdown, list) { |
| 54 | | if (markdown.startsWith('*')) { |
| 55 | | const innerHtml = wrap(parseText(markdown.substring(2), true), 'li'); |
| 56 | | if (list) { |
| 57 | | return [innerHtml, true]; |
| 58 | | } else { |
| 59 | | return [`<ul>${innerHtml}`, true]; |
| 60 | | } |
| 33 | /** |
| 34 | * Parse a list item (* item -> <li>item</li>) |
| 35 | * @param {string} line - Line to parse |
| 36 | * @returns {string|null} - HTML list item or null if not a list item |
| 37 | */ |
| 38 | parseListItem(line) { |
| 39 | if (!line.startsWith('* ')) return null; |
| 40 | |
| 41 | const content = line.substring(2); |
| 42 | const formattedContent = this.parseInlineFormatting(content); |
| 43 | return `<li>${formattedContent}</li>`; |
| 61 | 44 | } |
| 62 | | return [null, list]; |
| 63 | | } |
| 64 | 45 | |
| 65 | | function parseParagraph(markdown, list) { |
| 66 | | if (!list) { |
| 67 | | return [parseText(markdown, false), false]; |
| 68 | | } else { |
| 69 | | return [`</ul>${parseText(markdown, false)}`, false]; |
| 46 | /** |
| 47 | * Parse a paragraph (regular text -> <p>text</p>) |
| 48 | * @param {string} line - Line to parse |
| 49 | * @returns {string} - HTML paragraph |
| 50 | */ |
| 51 | parseParagraph(line) { |
| 52 | const formattedContent = this.parseInlineFormatting(line); |
| 53 | return `<p>${formattedContent}</p>`; |
| 70 | 54 | } |
| 71 | | } |
| 72 | 55 | |
| 73 | | function parseLine(markdown, list) { |
| 74 | | let [result, inListAfter] = parseHeader(markdown, list); |
| 75 | | if (result === null) { |
| 76 | | [result, inListAfter] = parseLineItem(markdown, list); |
| 77 | | } |
| 78 | | if (result === null) { |
| 79 | | [result, inListAfter] = parseParagraph(markdown, list); |
| 80 | | } |
| 81 | | if (result === null) { |
| 82 | | throw new Error('Remove this line and implement the function'); |
| 56 | /** |
| 57 | * Parse a single line of Markdown |
| 58 | * @param {string} line - Line to parse |
| 59 | * @param {boolean} inList - Whether we're currently in a list |
| 60 | * @returns {object} - Object with html and newListState properties |
| 61 | */ |
| 62 | parseLine(line, inList) { |
| 63 | // Try to parse as header |
| 64 | const header = this.parseHeader(line); |
| 65 | if (header) { |
| 66 | return { |
| 67 | html: (inList ? '</ul>' : '') + header, |
| 68 | newListState: false |
| 69 | }; |
| 70 | } |
| 71 | |
| 72 | // Try to parse as list item |
| 73 | const listItem = this.parseListItem(line); |
| 74 | if (listItem) { |
| 75 | return { |
| 76 | html: (inList ? '' : '<ul>') + listItem, |
| 77 | newListState: true |
| 78 | }; |
| 79 | } |
| 80 | |
| 81 | // Parse as paragraph |
| 82 | const paragraph = this.parseParagraph(line); |
| 83 | return { |
| 84 | html: (inList ? '</ul>' : '') + paragraph, |
| 85 | newListState: false |
| 86 | }; |
| 83 | 87 | } |
| 84 | | return [result, inListAfter]; |
| 85 | 88 | } |
| 86 | 89 | |
| 87 | 90 | /** |
| 88 | | * @param {string} markdown |
| 89 | | * @returns {string} |
| 91 | * Parse Markdown text and convert it to HTML |
| 92 | * @param {string} markdown - Markdown text to parse |
| 93 | * @returns {string} - HTML representation of the Markdown |
| 90 | 94 | */ |
| 91 | 95 | export function parse(markdown) { |
| 96 | const parser = new MarkdownParser(); |
| 92 | 97 | const lines = markdown.split('\n'); |
| 93 | | let result = ''; |
| 94 | | let list = false; |
| 95 | | for (let i = 0; i < lines.length; i++) { |
| 96 | | let [lineResult, newList] = parseLine(lines[i], list); |
| 97 | | result += lineResult; |
| 98 | | list = newList; |
| 98 | let html = ''; |
| 99 | let inList = false; |
| 100 | |
| 101 | for (const line of lines) { |
| 102 | const result = parser.parseLine(line, inList); |
| 103 | html += result.html; |
| 104 | inList = result.newListState; |
| 99 | 105 | } |
| 100 | | if (list) { |
| 101 | | return result + '</ul>'; |
| 102 | | } else { |
| 103 | | return result; |
| 106 | |
| 107 | // Close any open list at the end |
| 108 | if (inList) { |
| 109 | html += '</ul>'; |
| 104 | 110 | } |
| 111 | |
| 112 | return html; |
| 105 | 113 | } |