source: node_modules/prismjs/components/prism-wren.js

// https://wren.io/

Prism.languages.wren = {
        // Multiline comments in Wren can have nested multiline comments
        // Comments: // and /* */
        'comment': [
                {
                        // support 3 levels of nesting
                        // regex: \/\*(?:[^*/]|\*(?!\/)|\/(?!\*)|<self>)*\*\/
                        pattern: /\/\*(?:[^*/]|\*(?!\/)|\/(?!\*)|\/\*(?:[^*/]|\*(?!\/)|\/(?!\*)|\/\*(?:[^*/]|\*(?!\/)|\/(?!\*))*\*\/)*\*\/)*\*\//,
                        greedy: true
                },
                {
                        pattern: /(^|[^\\:])\/\/.*/,
                        lookbehind: true,
                        greedy: true
                }
        ],

        // Triple quoted strings are multiline but cannot have interpolation (raw strings)
        // Based on prism-python.js
        'triple-quoted-string': {
                pattern: /"""[\s\S]*?"""/,
                greedy: true,
                alias: 'string'
        },

        // see below
        'string-literal': null,

        // #!/usr/bin/env wren on the first line
        'hashbang': {
                pattern: /^#!\/.+/,
                greedy: true,
                alias: 'comment'
        },

        // Attributes are special keywords to add meta data to classes
        'attribute': {
                // #! attributes are stored in class properties
                // #!myvar = true
                // #attributes are not stored and dismissed at compilation
                pattern: /#!?[ \t\u3000]*\w+/,
                alias: 'keyword'
        },
        'class-name': [
                {
                        // class definition
                        // class Meta {}
                        pattern: /(\bclass\s+)\w+/,
                        lookbehind: true
                },
                // A class must always start with an uppercase.
                // File.read
                /\b[A-Z][a-z\d_]*\b/,
        ],

        // A constant can be a variable, class, property or method. Just named in all uppercase letters
        'constant': /\b[A-Z][A-Z\d_]*\b/,

        'null': {
                pattern: /\bnull\b/,
                alias: 'keyword'
        },
        'keyword': /\b(?:as|break|class|construct|continue|else|for|foreign|if|import|in|is|return|static|super|this|var|while)\b/,
        'boolean': /\b(?:false|true)\b/,
        'number': /\b(?:0x[\da-f]+|\d+(?:\.\d+)?(?:e[+-]?\d+)?)\b/i,

        // Functions can be Class.method()
        'function': /\b[a-z_]\w*(?=\s*[({])/i,

        'operator': /<<|>>|[=!<>]=?|&&|\|\||[-+*/%~^&|?:]|\.{2,3}/,
        'punctuation': /[\[\](){}.,;]/,
};

Prism.languages.wren['string-literal'] = {
        // A single quote string is multiline and can have interpolation (similar to JS backticks ``)
        pattern: /(^|[^\\"])"(?:[^\\"%]|\\[\s\S]|%(?!\()|%\((?:[^()]|\((?:[^()]|\([^)]*\))*\))*\))*"/,
        lookbehind: true,
        greedy: true,
        inside: {
                'interpolation': {
                        // "%(interpolation)"
                        pattern: /((?:^|[^\\])(?:\\{2})*)%\((?:[^()]|\((?:[^()]|\([^)]*\))*\))*\)/,
                        lookbehind: true,
                        inside: {
                                'expression': {
                                        pattern: /^(%\()[\s\S]+(?=\)$)/,
                                        lookbehind: true,
                                        inside: Prism.languages.wren
                                },
                                'interpolation-punctuation': {
                                        pattern: /^%\(|\)$/,
                                        alias: 'punctuation'
                                },
                        }
                },
                'string': /[\s\S]+/
        }
};