Added support for SML (#2537)

components.json

@@ -1053,6 +1053,14 @@
 			"require": "markup-templating",
 			"owner": "Golmote"
 		},
+		"sml": {
+			"title": "SML",
+			"alias": "smlnj",
+			"aliasTitles": {
+				"smlnj": "SML/NJ"
+			},
+			"owner": "RunDevelopment"
+		},
 		"solidity": {
 			"title": "Solidity (Ethereum)",
 			"alias": "sol",

components/prism-sml.js

@@ -0,0 +1,68 @@
+// 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));

examples/prism-sml.html

@@ -0,0 +1,43 @@
+<h2>Full example</h2>
+<pre><code>(* source: https://github.com/HarrisonGrodin/ml-numbers/blob/ba35c763092052e391871edf224f17474c6231b1/src/Rational.sml *)
+
+structure Rational :> RATIONAL =
+  struct
+    type t = int * int  (* (a,b) invariant: a,b coprime; b nonnegative *)
+
+    local
+      val rec gcd = fn
+        (m,0) => m
+      | (m,n) => gcd (n, m mod n)
+    in
+      infix 8 //
+      val op // = fn (x,y) => (
+        let
+          val gcd = gcd (x,y)
+        in
+          (x div gcd, y div gcd)
+        end
+      )
+    end
+
+    val show = Fn.id
+
+    val zero = (0,1)
+    val one  = (1,1)
+
+    val eq : t * t -> bool = (op =)
+    val compare = fn ((a,b),(x,y)) => Int.compare (a * y, b * x)
+    val toString = fn (x,y) => Int.toString x ^ " // " ^ Int.toString y
+    val percent =
+      Fn.curry (Fn.flip (op ^)) "%"
+      o Int.toString
+      o (fn (a,b) => (100 * a) div b)
+
+    val op + = fn ((a,b),(x,y)) => (a * y + b * x) // (b * y)
+    val ~ = fn (a,b) => (~a,b)
+    val op - = fn (r1,r2) => r1 + ~r2
+
+    val op * = fn ((a,b),(x,y)) => (a * x) // (b * y)
+    val inv = Fn.flip (op //)
+    val op / = fn (r1,r2) => r1 * inv r2
+  end</code></pre>

plugins/autoloader/prism-autoloader.js

@@ -207,6 +207,7 @@
 		"rb": "ruby",
 		"sh-session": "shell-session",
 		"shellsession": "shell-session",
+		"smlnj": "sml",
 		"sol": "solidity",
 		"sln": "solution-file",
 		"rq": "sparql",

plugins/show-language/prism-show-language.js

@@ -169,6 +169,8 @@
 		"shell-session": "Shell session",
 		"sh-session": "Shell session",
 		"shellsession": "Shell session",
+		"sml": "SML",
+		"smlnj": "SML/NJ",
 		"solidity": "Solidity (Ethereum)",
 		"sol": "Solidity (Ethereum)",
 		"solution-file": "Solution file",