Add support for function with outputs but no inputs (#200)

* Add support for function with outputs but no inputs

This commit adds a specific lexer for a function with outputs but no
inputs (or parentheses)

* Appease the black gods

* Fix typo in comment

Author: H0R5E

sphinxcontrib/mat_lexer.py

@@ -338,7 +338,15 @@ class MatlabLexer(RegexLexer):
                 ),
                 "#pop",
             ),
-            # function with no args
+            # function with outputs but no inputs
+            (
+                r"(\s*)(?:(.+)(\s*)(=)(\s*))?([a-zA-Z_]\w*)",
+                bygroups(
+                    Whitespace, Text, Whitespace, Punctuation, Whitespace, Name.Function
+                ),
+                "#pop",
+            ),
+            # function with no inputs or outputs
             (r"(\s*)([a-zA-Z_]\w*)", bygroups(Text, Name.Function), "#pop"),
         ],
     }

tests/test_data/f_no_input_no_parentheses_no_docstring.m

@@ -0,0 +1,2 @@
+function result = f_no_input_no_parentheses_no_docstring
+result = 1

tests/test_matlabify.py

@@ -68,6 +68,7 @@ def test_module(mod):
         "Bool",
         "ClassWithEvent",
         "f_no_input_no_output_no_parentheses",
+        "f_no_input_no_parentheses_no_docstring",
         "ClassWithCommentHeader",
         "f_with_comment_header",
         "f_with_dummy_argument",

tests/test_parse_mfile.py

@@ -210,6 +210,18 @@ def test_no_input_no_output_no_parentheses():
     )
 
 
+def test_no_input_no_parentheses_no_docstring():
+    mfile = os.path.join(
+        DIRNAME, "test_data", "f_no_input_no_parentheses_no_docstring.m"
+    )
+    obj = mat_types.MatObject.parse_mfile(
+        mfile, "f_no_input_no_parentheses_no_docstring", "test_data"
+    )
+    assert obj.name == "f_no_input_no_parentheses_no_docstring"
+    assert obj.retv == ["result"]
+    assert obj.args is None
+
+
 def test_ClassWithCommentHeader():
     mfile = os.path.join(DIRNAME, "test_data", "ClassWithCommentHeader.m")
     obj = mat_types.MatObject.parse_mfile(mfile, "ClassWithCommentHeader", "test_data")