Lexer for new language Maxima (#1885)

* New lexer for Maxima computer algebra system

 * New lexer class MaximaLexer
 * Update _mapping.py to include Maxima lexer
 * New test input file maxima/foo.mac

I find that the commands

$ python3 -m pygments -O full -f html -o /tmp/foo.html tests/examplefiles/maxima/foo.mac

$ python3 -m pygments -x -l pygments/lexers/maxima.py:MaximaLexer tests/examplefiles/maxima/foo.mac

both produce expected output.

* Commit output from pytest --update-goldens for Maxima example file

Commit output from pytest tests/examplefiles/maxima --update-goldens
as obtained by Cameron Smith.

* Rename output file for test of Maxima lexer.

* In Maxima lexer, capture content of comment
all at once, instead of capturing each character separately.

Update expected output for example input file, as produce by:

$ pytest tests/examplefiles/maxima --update-goldens

* In lexer for Maxima language, identify whitespace characters as such
instead of just calling them Text.

* In lexer for Maxima language, identify comma, semicolon, and dollar sign
as Punctuation instead of Text.

* In lexer for Maxima language, cut encoding comment, and put in license statement.

* In lexer for Maxima language, identify keywords and other fixed strings such as operators
via the words function, instead of a long regex with alternation.

Incidentally update the example output, for which one symbol
(namely "done") has changed classification.

* In lexer for Maxima language, include additional test input and update output accordingly.

* In lexer for Maxima language, relax pattern for integers,
so integers are more accurately identified.

Update test example output accordingly.

* In lexer for Maxima language, adjust pattern for float numbers.
Include additional test input for floats and update expected output.

* In lexer for Maxima language, define analyse_text function.

* In lexer for Maxima language, correct errors identified by make check

(1) adjust package name underline
(2) put in copyright notice

Co-authored-by: Robert Dodier <robert_dodier@users.sourceforge.net>

4 files changed, 604 insertions, 0 deletions

diff --git a/pygments/lexers/_mapping.py b/pygments/lexers/_mapping.py
index 24e3668d..2ad7467e 100644
--- a/pygments/lexers/_mapping.py
+++ b/pygments/lexers/_mapping.py
@@ -286,6 +286,7 @@ LEXERS = {
     'MathematicaLexer': ('pygments.lexers.algebra', 'Mathematica', ('mathematica', 'mma', 'nb'), ('*.nb', '*.cdf', '*.nbp', '*.ma'), ('application/mathematica', 'application/vnd.wolfram.mathematica', 'application/vnd.wolfram.mathematica.package', 'application/vnd.wolfram.cdf')),
     'MatlabLexer': ('pygments.lexers.matlab', 'Matlab', ('matlab',), ('*.m',), ('text/matlab',)),
     'MatlabSessionLexer': ('pygments.lexers.matlab', 'Matlab session', ('matlabsession',), (), ()),
+    'MaximaLexer': ('pygments.lexers.maxima', 'Maxima', ('maxima', 'macsyma'), ('*.mac', '*.max'), ()),
     'MesonLexer': ('pygments.lexers.meson', 'Meson', ('meson', 'meson.build'), ('meson.build', 'meson_options.txt'), ('text/x-meson',)),
     'MiniDLexer': ('pygments.lexers.d', 'MiniD', ('minid',), (), ('text/x-minidsrc',)),
     'MiniScriptLexer': ('pygments.lexers.scripting', 'MiniScript', ('miniscript', 'ms'), ('*.ms',), ('text/x-minicript', 'application/x-miniscript')),
diff --git a/pygments/lexers/maxima.py b/pygments/lexers/maxima.py
new file mode 100644
index 00000000..4c76df36
--- /dev/null
+++ b/pygments/lexers/maxima.py
@@ -0,0 +1,82 @@
+"""
+    pygments.lexers.maxima
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    Lexer for the computer algebra system Maxima.
+
+    Derived from pygments/lexers/algebra.py.
+
+    :copyright: Copyright 2006-2021 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import re
+
+from pygments.lexer import RegexLexer, bygroups, words
+from pygments.token import Text, Comment, Operator, Keyword, Name, String, \
+    Number, Punctuation
+
+__all__ = ['MaximaLexer']
+
+class MaximaLexer(RegexLexer):
+    """
+    A `Maxima <http://maxima.sourceforge.net>`_ lexer.
+    Derived from pygments.lexers.MuPADLexer.
+    """
+    name = 'Maxima'
+    aliases = ['maxima', 'macsyma']
+    filenames = ['*.mac', '*.max']
+
+    keywords = ('if', 'then', 'else', 'elseif',
+                'do', 'while', 'repeat', 'until',
+                'for', 'from', 'to', 'downto', 'step', 'thru')
+
+    constants = ('%pi', '%e', '%phi', '%gamma', '%i',
+                 'und', 'ind', 'infinity', 'inf', 'minf',
+                 'true', 'false', 'unknown', 'done')
+
+    operators = (r'.', r':', r'=', r'#',
+                 r'+', r'-', r'*', r'/', r'^',
+                 r'@', r'>', r'<', r'|', r'!', r"'")
+
+    operator_words = ('and', 'or', 'not')
+
+    tokens = {
+        'root': [
+            (r'/\*', Comment.Multiline, 'comment'),
+            (r'"(?:[^"\\]|\\.)*"', String),
+            (r'\(|\)|\[|\]|\{|\}', Punctuation),
+            (r'[,;$]', Punctuation),
+            (words (constants), Name.Constant),
+            (words (keywords), Keyword),
+            (words (operators), Operator),
+            (words (operator_words), Operator.Word),
+            (r'''(?x)
+              ((?:[a-zA-Z_#][\w#]*|`[^`]*`)
+              (?:::[a-zA-Z_#][\w#]*|`[^`]*`)*)(\s*)([(])''',
+             bygroups(Name.Function, Text.Whitespace, Punctuation)),
+            (r'''(?x)
+              (?:[a-zA-Z_#%][\w#%]*|`[^`]*`)
+              (?:::[a-zA-Z_#%][\w#%]*|`[^`]*`)*''', Name.Variable),
+            (r'[-+]?(\d*\.\d+([bdefls][-+]?\d+)?|\d+(\.\d*)?[bdefls][-+]?\d+)', Number.Float),
+            (r'[-+]?\d+', Number.Integer),
+            (r'\s+', Text.Whitespace),
+            (r'.', Text)
+        ],
+        'comment': [
+            (r'[^*/]+', Comment.Multiline),
+            (r'/\*', Comment.Multiline, '#push'),
+            (r'\*/', Comment.Multiline, '#pop'),
+            (r'[*/]', Comment.Multiline)
+        ]
+    }
+
+    def analyse_text (text):
+        strength = 0.0
+        # Input expression terminator.
+        if re.search (r'\$\s*$', text, re.MULTILINE):
+            strength += 0.05
+        # Function definition operator.
+        if ':=' in text:
+            strength += 0.02
+        return strength
diff --git a/tests/examplefiles/maxima/foo.mac b/tests/examplefiles/maxima/foo.mac
new file mode 100644
index 00000000..f3b1060f
--- /dev/null
+++ b/tests/examplefiles/maxima/foo.mac
@@ -0,0 +1,40 @@
+/* SF bug #3826: "limit returns temp variable expression" */
+
+(kill (q, a, x),
+ ctxt: newcontext (),
+ assume (q > 0),
+ limit(x^q/(a*x^q- 1),x,inf));
+'limit(1/(a- 1/x^q),x,inf);
+
+tlimit(x^q/(a*x^q- 1),x,inf);
+'limit(1/(a- 1/x^q),x,inf);
+
+(assume (a > 0),
+ declare (q, integer),
+ limit(x^q/(a*x^q- 1),x,inf));
+1/a;
+
+(remove (q, integer),
+ declare (q, noninteger),
+ limit(x^q/(a*x^q- 1),x,inf));
+1/a;
+
+(remove (q, noninteger),
+ killcontext (ctxt));
+done;
+
+/* additional code to test lexer */
+
+xyz: expand ((u - h*v)^4);
+print ("foo.mac: xyz =", xyz);
+'integrate (xyz, u, minf, inf);
+LL: [1234, 5678, 9012];
+for x:2 thru n - 3
+    do while (L: readline (S)) # false
+           do push (L, LL);
+if abc < 123 and (def > -123 or zyx < 234)
+    then X[k]: Y[j, k]*%pi - gamma;
+
+print ("foo.mac: test different kinds of floats") $
+blurf (a, b, c) :=
+    mumble (a*123.45/b, b*0.12345e6/c, c*1.2345b-8/a)) $
diff --git a/tests/examplefiles/maxima/foo.mac.output b/tests/examplefiles/maxima/foo.mac.output
new file mode 100644
index 00000000..e63fda83
--- /dev/null
+++ b/tests/examplefiles/maxima/foo.mac.output
@@ -0,0 +1,481 @@
+'/*'          Comment.Multiline
+' SF bug #3826: "limit returns temp variable expression" ' Comment.Multiline
+'*/'          Comment.Multiline
+'\n\n'        Text.Whitespace
+
+'('           Punctuation
+'kill'        Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'q'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'a'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'x'           Name.Variable
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'ctxt'        Name.Variable
+':'           Operator
+' '           Text.Whitespace
+'newcontext'  Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'assume'      Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'q'           Name.Variable
+' '           Text.Whitespace
+'>'           Operator
+' '           Text.Whitespace
+'0'           Literal.Number.Integer
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'limit'       Name.Function
+'('           Punctuation
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'/'           Operator
+'('           Punctuation
+'a'           Name.Variable
+'*'           Operator
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'-'           Operator
+' '           Text.Whitespace
+'1'           Literal.Number.Integer
+')'           Punctuation
+','           Punctuation
+'x'           Name.Variable
+','           Punctuation
+'inf'         Name.Constant
+')'           Punctuation
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+"'"           Operator
+'limit'       Name.Function
+'('           Punctuation
+'1'           Literal.Number.Integer
+'/'           Operator
+'('           Punctuation
+'a'           Name.Variable
+'-'           Operator
+' '           Text.Whitespace
+'1'           Literal.Number.Integer
+'/'           Operator
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+')'           Punctuation
+','           Punctuation
+'x'           Name.Variable
+','           Punctuation
+'inf'         Name.Constant
+')'           Punctuation
+';'           Punctuation
+'\n\n'        Text.Whitespace
+
+'tlimit'      Name.Function
+'('           Punctuation
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'/'           Operator
+'('           Punctuation
+'a'           Name.Variable
+'*'           Operator
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'-'           Operator
+' '           Text.Whitespace
+'1'           Literal.Number.Integer
+')'           Punctuation
+','           Punctuation
+'x'           Name.Variable
+','           Punctuation
+'inf'         Name.Constant
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+"'"           Operator
+'limit'       Name.Function
+'('           Punctuation
+'1'           Literal.Number.Integer
+'/'           Operator
+'('           Punctuation
+'a'           Name.Variable
+'-'           Operator
+' '           Text.Whitespace
+'1'           Literal.Number.Integer
+'/'           Operator
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+')'           Punctuation
+','           Punctuation
+'x'           Name.Variable
+','           Punctuation
+'inf'         Name.Constant
+')'           Punctuation
+';'           Punctuation
+'\n\n'        Text.Whitespace
+
+'('           Punctuation
+'assume'      Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'a'           Name.Variable
+' '           Text.Whitespace
+'>'           Operator
+' '           Text.Whitespace
+'0'           Literal.Number.Integer
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'declare'     Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'q'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'integer'     Name.Variable
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'limit'       Name.Function
+'('           Punctuation
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'/'           Operator
+'('           Punctuation
+'a'           Name.Variable
+'*'           Operator
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'-'           Operator
+' '           Text.Whitespace
+'1'           Literal.Number.Integer
+')'           Punctuation
+','           Punctuation
+'x'           Name.Variable
+','           Punctuation
+'inf'         Name.Constant
+')'           Punctuation
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'1'           Literal.Number.Integer
+'/'           Operator
+'a'           Name.Variable
+';'           Punctuation
+'\n\n'        Text.Whitespace
+
+'('           Punctuation
+'remove'      Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'q'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'integer'     Name.Variable
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'declare'     Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'q'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'noninteger'  Name.Variable
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'limit'       Name.Function
+'('           Punctuation
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'/'           Operator
+'('           Punctuation
+'a'           Name.Variable
+'*'           Operator
+'x'           Name.Variable
+'^'           Operator
+'q'           Name.Variable
+'-'           Operator
+' '           Text.Whitespace
+'1'           Literal.Number.Integer
+')'           Punctuation
+','           Punctuation
+'x'           Name.Variable
+','           Punctuation
+'inf'         Name.Constant
+')'           Punctuation
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'1'           Literal.Number.Integer
+'/'           Operator
+'a'           Name.Variable
+';'           Punctuation
+'\n\n'        Text.Whitespace
+
+'('           Punctuation
+'remove'      Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'q'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'noninteger'  Name.Variable
+')'           Punctuation
+','           Punctuation
+'\n '         Text.Whitespace
+'killcontext' Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'ctxt'        Name.Variable
+')'           Punctuation
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'done'        Name.Constant
+';'           Punctuation
+'\n\n'        Text.Whitespace
+
+'/*'          Comment.Multiline
+' additional code to test lexer ' Comment.Multiline
+'*/'          Comment.Multiline
+'\n\n'        Text.Whitespace
+
+'xyz'         Name.Variable
+':'           Operator
+' '           Text.Whitespace
+'expand'      Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'('           Punctuation
+'u'           Name.Variable
+' '           Text.Whitespace
+'-'           Operator
+' '           Text.Whitespace
+'h'           Name.Variable
+'*'           Operator
+'v'           Name.Variable
+')'           Punctuation
+'^'           Operator
+'4'           Literal.Number.Integer
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'print'       Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'"foo.mac: xyz ="' Literal.String
+','           Punctuation
+' '           Text.Whitespace
+'xyz'         Name.Variable
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+"'"           Operator
+'integrate'   Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'xyz'         Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'u'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'minf'        Name.Constant
+','           Punctuation
+' '           Text.Whitespace
+'inf'         Name.Constant
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'LL'          Name.Variable
+':'           Operator
+' '           Text.Whitespace
+'['           Punctuation
+'1234'        Literal.Number.Integer
+','           Punctuation
+' '           Text.Whitespace
+'5678'        Literal.Number.Integer
+','           Punctuation
+' '           Text.Whitespace
+'9012'        Literal.Number.Integer
+']'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'for'         Keyword
+' '           Text.Whitespace
+'x'           Name.Variable
+':'           Operator
+'2'           Literal.Number.Integer
+' '           Text.Whitespace
+'thru'        Keyword
+' '           Text.Whitespace
+'n'           Name.Variable
+' '           Text.Whitespace
+'-'           Operator
+' '           Text.Whitespace
+'3'           Literal.Number.Integer
+'\n    '      Text.Whitespace
+'do'          Keyword
+' '           Text.Whitespace
+'while'       Keyword
+' '           Text.Whitespace
+'('           Punctuation
+'L'           Name.Variable
+':'           Operator
+' '           Text.Whitespace
+'readline'    Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'S'           Name.Variable
+')'           Punctuation
+')'           Punctuation
+' '           Text.Whitespace
+'#'           Operator
+' '           Text.Whitespace
+'false'       Name.Constant
+'\n           ' Text.Whitespace
+'do'          Keyword
+' '           Text.Whitespace
+'push'        Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'L'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'LL'          Name.Variable
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'if'          Keyword
+' '           Text.Whitespace
+'abc'         Name.Variable
+' '           Text.Whitespace
+'<'           Operator
+' '           Text.Whitespace
+'123'         Literal.Number.Integer
+' '           Text.Whitespace
+'and'         Operator.Word
+' '           Text.Whitespace
+'('           Punctuation
+'def'         Name.Variable
+' '           Text.Whitespace
+'>'           Operator
+' '           Text.Whitespace
+'-'           Operator
+'123'         Literal.Number.Integer
+' '           Text.Whitespace
+'or'          Operator.Word
+' '           Text.Whitespace
+'zyx'         Name.Variable
+' '           Text.Whitespace
+'<'           Operator
+' '           Text.Whitespace
+'234'         Literal.Number.Integer
+')'           Punctuation
+'\n    '      Text.Whitespace
+'then'        Keyword
+' '           Text.Whitespace
+'X'           Name.Variable
+'['           Punctuation
+'k'           Name.Variable
+']'           Punctuation
+':'           Operator
+' '           Text.Whitespace
+'Y'           Name.Variable
+'['           Punctuation
+'j'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'k'           Name.Variable
+']'           Punctuation
+'*'           Operator
+'%pi'         Name.Constant
+' '           Text.Whitespace
+'-'           Operator
+' '           Text.Whitespace
+'gamma'       Name.Variable
+';'           Punctuation
+'\n\n'        Text.Whitespace
+
+'print'       Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'"foo.mac: test different kinds of floats"' Literal.String
+')'           Punctuation
+' '           Text.Whitespace
+'$'           Punctuation
+'\n'          Text.Whitespace
+
+'blurf'       Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'a'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'b'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'c'           Name.Variable
+')'           Punctuation
+' '           Text.Whitespace
+':'           Operator
+'='           Operator
+'\n    '      Text.Whitespace
+'mumble'      Name.Function
+' '           Text.Whitespace
+'('           Punctuation
+'a'           Name.Variable
+'*'           Operator
+'123.45'      Literal.Number.Float
+'/'           Operator
+'b'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'b'           Name.Variable
+'*'           Operator
+'0.12345e6'   Literal.Number.Float
+'/'           Operator
+'c'           Name.Variable
+','           Punctuation
+' '           Text.Whitespace
+'c'           Name.Variable
+'*'           Operator
+'1.2345b-8'   Literal.Number.Float
+'/'           Operator
+'a'           Name.Variable
+')'           Punctuation
+')'           Punctuation
+' '           Text.Whitespace
+'$'           Punctuation
+'\n'          Text.Whitespace