Add MiniZinc lexer (#1329)

This commit adds a lexer for the MiniZinc language.

* Shorten link

* Simplify ID regex

* Remove unnecessary newline rule

* Simplify single comment rule

* Change priority of generic identifier rule

* Remove unnecessary parentheses

lib/rouge/demos/minizinc

@@ -0,0 +1,23 @@
+% from MiniZinc Handbook:
+% https://www.minizinc.org/doc-latest/en/modelling.html
+
+% Colouring Australia using nc colours
+int: nc = 3;
+
+var 1..nc: wa;   var 1..nc: nt;  var 1..nc: sa;   var 1..nc: q;
+var 1..nc: nsw;  var 1..nc: v;   var 1..nc: t;
+
+constraint wa != nt;
+constraint wa != sa;
+constraint nt != sa;
+constraint nt != q;
+constraint sa != q;
+constraint sa != nsw;
+constraint sa != v;
+constraint q != nsw;
+constraint nsw != v;
+solve satisfy;
+
+output ["wa=\(wa)\t nt=\(nt)\t sa=\(sa)\n",
+        "q=\(q)\t nsw=\(nsw)\t v=\(v)\n",
+         "t=", show(t),  "\n"];

lib/rouge/lexers/minizinc.rb

@@ -0,0 +1,87 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+# Based on Chroma's MiniZinc lexer:
+# https://github.com/alecthomas/chroma/blob/5152194c717b394686d3d7a7e1946a360ec0728f/lexers/m/minizinc.go
+
+module Rouge
+  module Lexers
+    class MiniZinc < RegexLexer
+      title "MiniZinc"
+      desc "MiniZinc is a free and open-source constraint modeling language (minizinc.org)"
+      tag 'minizinc'
+      filenames '*.mzn', '*.fzn', '*.dzn'
+      mimetypes 'text/minizinc'
+
+      def self.builtins
+        @builtins = Set.new %w[
+          abort abs acosh array_intersect array_union array1d array2d array3d
+          array4d array5d array6d asin assert atan bool2int card ceil concat
+          cos cosh dom dom_array dom_size fix exp floor index_set
+          index_set_1of2 index_set_2of2 index_set_1of3 index_set_2of3
+          index_set_3of3 int2float is_fixed join lb lb_array length ln log log2
+          log10 min max pow product round set2array show show_int show_float
+          sin sinh sqrt sum tan tanh trace ub ub_array
+        ]
+      end
+
+      def self.keywords
+        @keywords = Set.new %w[
+          ann annotation any constraint else endif function for forall if
+          include list of op output minimize maximize par predicate record
+          satisfy solve test then type var where
+        ]
+      end
+
+      def self.keywords_type
+        @keywords_type ||= Set.new %w(
+          array set bool enum float int string tuple
+        )
+      end
+
+      def self.operators
+        @operators ||= Set.new %w(
+          in subset superset union diff symdiff intersect
+        )
+      end
+
+      id = /[$a-zA-Z_]\w*/
+
+      state :root do
+        rule %r(\s+)m, Text::Whitespace
+        rule %r(\\\n)m, Text::Whitespace
+        rule %r(%.*), Comment::Single
+        rule %r(/(\\\n)?[*](.|\n)*?[*](\\\n)?/)m, Comment::Multiline
+        rule %r/"(\\\\|\\"|[^"])*"/, Literal::String
+
+        rule %r(not|<->|->|<-|\\/|xor|/\\), Operator
+        rule %r(<|>|<=|>=|==|=|!=), Operator
+        rule %r(\+|-|\*|/|div|mod), Operator
+        rule %r(\\|\.\.|\+\+), Operator
+        rule %r([|()\[\]{},:;]), Punctuation
+        rule %r((true|false)\b), Keyword::Constant
+        rule %r(([+-]?)\d+(\.(?!\.)\d*)?([eE][-+]?\d+)?), Literal::Number
+
+        rule id do |m|
+          if self.class.keywords.include? m[0]
+            token Keyword
+          elsif self.class.keywords_type.include? m[0]
+            token Keyword::Type
+          elsif self.class.builtins.include? m[0]
+            token Name::Builtin
+          elsif self.class.operators.include? m[0]
+            token Operator
+          else
+            token Name::Other
+          end
+        end
+
+        rule %r(::\s*([^\W\d]\w*)(\s*\([^\)]*\))?), Name::Decorator
+        rule %r(\b([^\W\d]\w*)\b(\()) do
+          groups Name::Function, Punctuation
+        end
+        rule %r([^\W\d]\w*), Name::Other
+      end
+    end
+  end
+end

spec/lexers/minizinc_spec.rb

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+describe Rouge::Lexers::MiniZinc do
+  let(:subject) { Rouge::Lexers::MiniZinc.new }
+
+  describe 'guessing' do
+    include Support::Guessing
+
+    it 'guesses by filename' do
+      assert_guess :filename => 'foo.mzn'
+      assert_guess :filename => 'foo.fzn'
+      assert_guess :filename => 'foo.dzn'
+    end
+
+    it 'guesses by mimetype' do
+      assert_guess :mimetype => 'text/minizinc'
+    end
+  end
+end

spec/visual/samples/minizinc

@@ -0,0 +1,48 @@
+% from MiniZinc Handbook:
+% https://www.minizinc.org/doc-latest/en/predicates.html
+
+% Simple nurse rostering
+include "regular.mzn";
+enum NURSE;
+enum DAY;
+int: req_day;
+int: req_night;
+int: min_night;
+
+enum SHIFT = { d, n, o };
+int: S = card(SHIFT);
+
+int: Q = 6; int: q0 = 1; set of int: STATE = 1..Q;
+array[STATE,SHIFT] of int: t =
+     [| 2, 3, 1    % state 1
+      | 4, 4, 1    % state 2
+      | 4, 5, 1    % state 3
+      | 6, 6, 1    % state 4
+      | 6, 0, 1    % state 5
+      | 0, 0, 1|]; % state 6
+
+array[NURSE,DAY] of var SHIFT: roster;
+
+constraint forall(j in DAY)(
+             sum(i in NURSE)(roster[i,j] == d) == req_day /\
+             sum(i in NURSE)(roster[i,j] == n) == req_night
+           );
+constraint forall(i in NURSE)(
+             regular([roster[i,j] | j in DAY], Q, S, t, q0, STATE) /\
+             sum(j in DAY)(roster[i,j] == n) >= min_night
+           );
+
+solve satisfy;
+
+output [ show(roster[i,j]) ++ if j==card(DAY) then "\n" else " " endif
+       | i in NURSE, j in DAY ];
+
+/*
+   Multiline
+   comment
+   test
+*/
+
+predicate atmostone(array[int] of var bool:x) =
+          forall(i,j in index_set(x) where i < j)(
+            (not x[i] \/ not x[j]));