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

// https://smlfamily.github.io/sml97-defn.pdf
// https://people.mpi-sws.org/~rossberg/sml.html
(function (Prism) {

        var keywords = /\b(?:abstype|and|andalso|as|case|datatype|do|else|end|eqtype|exception|fn|fun|functor|handle|if|in|include|infix|infixr|let|local|nonfix|of|op|open|orelse|raise|rec|sharing|sig|signature|struct|structure|then|type|val|where|while|with|withtype)\b/i;

        Prism.languages.sml = {
                // allow one level of nesting
                'comment': /\(\*(?:[^*(]|\*(?!\))|\((?!\*)|\(\*(?:[^*(]|\*(?!\))|\((?!\*))*\*\))*\*\)/,
                'string': {
                        pattern: /#?"(?:[^"\\]|\\.)*"/,
                        greedy: true
                },

                'class-name': [
                        {
                                // This is only an approximation since the real grammar is context-free
                                //
                                // Why the main loop so complex?
                                // The main loop is approximately the same as /(?:\s*(?:[*,]|->)\s*<TERMINAL>)*/ which is, obviously, a lot
                                // simpler. The difference is that if a comma is the last iteration of the loop, then the terminal must be
                                // followed by a long identifier.
                                pattern: RegExp(
                                        /((?:^|[^:]):\s*)<TERMINAL>(?:\s*(?:(?:\*|->)\s*<TERMINAL>|,\s*<TERMINAL>(?:(?=<NOT-LAST>)|(?!<NOT-LAST>)\s+<LONG-ID>)))*/.source
                                                .replace(/<NOT-LAST>/g, function () { return /\s*(?:[*,]|->)/.source; })
                                                .replace(/<TERMINAL>/g, function () {
                                                        return /(?:'[\w']*|<LONG-ID>|\((?:[^()]|\([^()]*\))*\)|\{(?:[^{}]|\{[^{}]*\})*\})(?:\s+<LONG-ID>)*/.source;
                                                })
                                                .replace(/<LONG-ID>/g, function () { return /(?!<KEYWORD>)[a-z\d_][\w'.]*/.source; })
                                                .replace(/<KEYWORD>/g, function () { return keywords.source; }),
                                        'i'
                                ),
                                lookbehind: true,
                                greedy: true,
                                inside: null // see below
                        },
                        {
                                pattern: /((?:^|[^\w'])(?:datatype|exception|functor|signature|structure|type)\s+)[a-z_][\w'.]*/i,
                                lookbehind: true
                        }
                ],
                'function': {
                        pattern: /((?:^|[^\w'])fun\s+)[a-z_][\w'.]*/i,
                        lookbehind: true
                },

                'keyword': keywords,
                'variable': {
                        pattern: /(^|[^\w'])'[\w']*/,
                        lookbehind: true,
                },

                'number': /~?\b(?:\d+(?:\.\d+)?(?:e~?\d+)?|0x[\da-f]+)\b/i,
                'word': {
                        pattern: /\b0w(?:\d+|x[\da-f]+)\b/i,
                        alias: 'constant'
                },

                'boolean': /\b(?:false|true)\b/i,
                'operator': /\.\.\.|:[>=:]|=>?|->|[<>]=?|[!+\-*/^#|@~]/,
                'punctuation': /[(){}\[\].:,;]/
        };

        Prism.languages.sml['class-name'][0].inside = Prism.languages.sml;

        Prism.languages.smlnj = Prism.languages.sml;

}(Prism));