add initial marp implementation with sample content and build configuration

node_modules/@marp-team/marpit/lib/markdown/directives/yaml.js

@@ -0,0 +1,62 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.yaml = exports.default = void 0;
+var _jsYaml = require("js-yaml");
+var _directives = _interopRequireDefault(require("./directives"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const createPatterns = keys => {
+  const set = new Set();
+  for (const k of keys) {
+    const normalized = '_?' + k.replace(/[.*+?^=!:${}()|[\]\\/]/g, '\\$&');
+    set.add(normalized);
+    set.add(`"${normalized}"`);
+    set.add(`'${normalized}'`);
+  }
+  return [...set.values()];
+};
+const yamlSpecialChars = `["'{|>~&*`;
+function parse(text) {
+  try {
+    const obj = (0, _jsYaml.load)(text, {
+      schema: _jsYaml.FAILSAFE_SCHEMA
+    });
+    if (obj === null || typeof obj !== 'object') return false;
+    return obj;
+  } catch {
+    return false;
+  }
+}
+function convertLoose(text, looseDirectives) {
+  const keyPattern = `(?:${createPatterns(looseDirectives).join('|')})`;
+  const looseMatcher = new RegExp(`^(${keyPattern}\\s*:)(.+)$`);
+  let normalized = '';
+  for (const line of text.split(/\r?\n/)) normalized += `${line.replace(looseMatcher, (original, prop, value) => {
+    const trimmed = value.trim();
+    if (trimmed.length === 0 || yamlSpecialChars.includes(trimmed[0])) return original;
+    const spaceLength = value.length - value.trimLeft().length;
+    const spaces = value.substring(0, spaceLength);
+    return `${prop}${spaces}"${trimmed.split('"').join('\\"')}"`;
+  })}\n`;
+  return normalized.trim();
+}
+
+/**
+ * Parse text as YAML by using js-yaml's FAILSAFE_SCHEMA.
+ *
+ * @function yaml
+ * @param {String} text Target text.
+ * @param {boolean|string[]} [looseDirectives=false] By setting `true`, it try
+ *     to parse as loose YAML only in defined Marpit built-in directives. You
+ *     may also extend target keys for loose parsing by passing an array of
+ *     strings.
+ * @returns {Object|false} Return parse result, or `false` when failed to parse.
+ */
+
+const yaml = (text, looseDirectives = false) => parse(looseDirectives ? convertLoose(text, [..._directives.default, ...(Array.isArray(looseDirectives) ? looseDirectives : [])]) : text);
+exports.yaml = yaml;
+var _default = exports.default = yaml;