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

// ABNF grammar:
// https://github.com/dhall-lang/dhall-lang/blob/master/standard/dhall.abnf

Prism.languages.dhall = {
        // Multi-line comments can be nested. E.g. {- foo {- bar -} -}
        // The multi-line pattern is essentially this:
        //   \{-(?:[^-{]|-(?!\})|\{(?!-)|<SELF>)*-\}
        'comment': /--.*|\{-(?:[^-{]|-(?!\})|\{(?!-)|\{-(?:[^-{]|-(?!\})|\{(?!-))*-\})*-\}/,
        'string': {
                pattern: /"(?:[^"\\]|\\.)*"|''(?:[^']|'(?!')|'''|''\$\{)*''(?!'|\$)/,
                greedy: true,
                inside: {
                        'interpolation': {
                                pattern: /\$\{[^{}]*\}/,
                                inside: {
                                        'expression': {
                                                pattern: /(^\$\{)[\s\S]+(?=\}$)/,
                                                lookbehind: true,
                                                alias: 'language-dhall',
                                                inside: null // see blow
                                        },
                                        'punctuation': /\$\{|\}/
                                }
                        }
                }
        },
        'label': {
                pattern: /`[^`]*`/,
                greedy: true
        },
        'url': {
                // https://github.com/dhall-lang/dhall-lang/blob/5fde8ef1bead6fb4e999d3c1ffe7044cd019d63a/standard/dhall.abnf#L596
                pattern: /\bhttps?:\/\/[\w.:%!$&'*+;=@~-]+(?:\/[\w.:%!$&'*+;=@~-]*)*(?:\?[/?\w.:%!$&'*+;=@~-]*)?/,
                greedy: true
        },
        'env': {
                // https://github.com/dhall-lang/dhall-lang/blob/5fde8ef1bead6fb4e999d3c1ffe7044cd019d63a/standard/dhall.abnf#L661
                pattern: /\benv:(?:(?!\d)\w+|"(?:[^"\\=]|\\.)*")/,
                greedy: true,
                inside: {
                        'function': /^env/,
                        'operator': /^:/,
                        'variable': /[\s\S]+/
                }
        },
        'hash': {
                // https://github.com/dhall-lang/dhall-lang/blob/5fde8ef1bead6fb4e999d3c1ffe7044cd019d63a/standard/dhall.abnf#L725
                pattern: /\bsha256:[\da-fA-F]{64}\b/,
                inside: {
                        'function': /sha256/,
                        'operator': /:/,
                        'number': /[\da-fA-F]{64}/
                }
        },

        // https://github.com/dhall-lang/dhall-lang/blob/5fde8ef1bead6fb4e999d3c1ffe7044cd019d63a/standard/dhall.abnf#L359
        'keyword': /\b(?:as|assert|else|forall|if|in|let|merge|missing|then|toMap|using|with)\b|\u2200/,
        'builtin': /\b(?:None|Some)\b/,

        'boolean': /\b(?:False|True)\b/,
        'number': /\bNaN\b|-?\bInfinity\b|[+-]?\b(?:0x[\da-fA-F]+|\d+(?:\.\d+)?(?:e[+-]?\d+)?)\b/,
        'operator': /\/\\|\/\/\\\\|&&|\|\||===|[!=]=|\/\/|->|\+\+|::|[+*#@=:?<>|\\\u2227\u2a53\u2261\u2afd\u03bb\u2192]/,
        'punctuation': /\.\.|[{}\[\](),./]/,

        // we'll just assume that every capital word left is a type name
        'class-name': /\b[A-Z]\w*\b/
};

Prism.languages.dhall.string.inside.interpolation.inside.expression.inside = Prism.languages.dhall;