ENH: add support for operator() in crackfortran.

Some interface name may contains parenthesis when used
with operator, like:
 interface operator(==)
   module procedure my_type_equals
 end interface operator(==)

Make the end part properly detected, and store also
the operator ('==' in that case) in the name.

Also implement support to list the implemented by in
any interface declaration.

doc/release/upcoming_changes/15006.new_feature.rst

@@ -0,0 +1,7 @@
+crackfortran has support for operator and assignement overloading
+-----------------------------------------------------------------
+``crackfortran`` parser now understands operator and assignement
+defintions in a module. They are added in the ``body`` list of the
+module which contains a new key ``implementedby`` listing the names
+of the subroutines or functions implementing the operator or
+assignment.

numpy/f2py/crackfortran.py

@@ -575,11 +575,16 @@ def readfortrancode(ffile, dowithline=show, istop=1):
 groupends = (r'end|endprogram|endblockdata|endmodule|endpythonmodule|'
              r'endinterface|endsubroutine|endfunction')
 endpattern = re.compile(
-    beforethisafter % ('', groupends, groupends, r'[\w\s]*'), re.I), 'end'
-endifs = r'(end\s*(if|do|where|select|while|forall|associate|block|critical|enum|team))|(module\s*procedure)'
+    beforethisafter % ('', groupends, groupends, r'.*'), re.I), 'end'
+endifs = r'end\s*(if|do|where|select|while|forall|associate|block|' + \
+         r'critical|enum|team)'
 endifpattern = re.compile(
     beforethisafter % (r'[\w]*?', endifs, endifs, r'[\w\s]*'), re.I), 'endif'
 #
+moduleprocedures = r'module\s*procedure'
+moduleprocedurepattern = re.compile(
+    beforethisafter % ('', moduleprocedures, moduleprocedures, r'.*'), re.I), \
+    'moduleprocedure'
 implicitpattern = re.compile(
     beforethisafter % ('', 'implicit', 'implicit', '.*'), re.I), 'implicit'
 dimensionpattern = re.compile(beforethisafter % (
@@ -728,7 +733,8 @@ def crackline(line, reset=0):
                 callpattern, usepattern, containspattern,
                 entrypattern,
                 f2pyenhancementspattern,
-                multilinepattern
+                multilinepattern,
+                moduleprocedurepattern
                 ]:
         m = pat[0].match(line)
         if m:
@@ -798,6 +804,8 @@ def crackline(line, reset=0):
         expectbegin = 0
     elif pat[1] == 'endif':
         pass
+    elif pat[1] == 'moduleprocedure':
+        analyzeline(m, pat[1], line)
     elif pat[1] == 'contains':
         if ignorecontains:
             return
@@ -886,6 +894,9 @@ def appenddecl(decl, decl2, force=1):
     r'\s*(?P<this>(@\(@.*?@\)@|\*[\d*]+|\*\s*@\(@.*?@\)@|))(?P<after>.*)\Z', re.I)
 nameargspattern = re.compile(
     r'\s*(?P<name>\b[\w$]+\b)\s*(@\(@\s*(?P<args>[\w\s,]*)\s*@\)@|)\s*((result(\s*@\(@\s*(?P<result>\b[\w$]+\b)\s*@\)@|))|(bind\s*@\(@\s*(?P<bind>.*)\s*@\)@))*\s*\Z', re.I)
+operatorpattern = re.compile(
+    r'\s*(?P<scheme>(operator|assignment))' + \
+    r'@\(@\s*(?P<name>[^)]+)\s*@\)@\s*\Z', re.I)
 callnameargspattern = re.compile(
     r'\s*(?P<name>\b[\w$]+\b)\s*@\(@\s*(?P<args>.*)\s*@\)@\s*\Z', re.I)
 real16pattern = re.compile(
@@ -908,6 +919,10 @@ def _resolvenameargspattern(line):
     m1 = nameargspattern.match(line)
     if m1:
         return m1.group('name'), m1.group('args'), m1.group('result'), m1.group('bind')
+    m1 = operatorpattern.match(line)
+    if m1:
+        name = m1.group('scheme') + '(' + m1.group('name') + ')'
+        return name, [], None, None
     m1 = callnameargspattern.match(line)
     if m1:
         return m1.group('name'), m1.group('args'), None, None
@@ -1151,6 +1166,9 @@ def analyzeline(m, case, line):
                     continue
             else:
                 k = rmbadname1(m1.group('name'))
+            if case in ['public', 'private'] and \
+               (k == 'operator' or k == 'assignment'):
+                k += m1.group('after')
             if k not in edecl:
                 edecl[k] = {}
             if case == 'dimension':
@@ -1193,6 +1211,9 @@ def analyzeline(m, case, line):
         groupcache[groupcounter]['vars'] = edecl
         if last_name is not None:
             previous_context = ('variable', last_name, groupcounter)
+    elif case == 'moduleprocedure':
+        groupcache[groupcounter]['implementedby'] = \
+            [x.strip() for x in m.group('after').split(',')]
     elif case == 'parameter':
         edecl = groupcache[groupcounter]['vars']
         ll = m.group('after').strip()[1:-1]
@@ -2105,7 +2126,8 @@ def analyzebody(block, args, tab=''):
         else:
             as_ = args
         b = postcrack(b, as_, tab=tab + '\t')
-        if b['block'] in ['interface', 'abstract interface'] and not b['body']:
+        if b['block'] in ['interface', 'abstract interface'] and \
+           not b['body'] and not b['implementedby']:
             if 'f2pyenhancements' not in b:
                 continue
         if b['block'].replace(' ', '') == 'pythonmodule':

numpy/f2py/tests/test_crackfortran.py

@@ -89,6 +89,41 @@ def test_defaultPublic(self, tmp_path):
         assert 'public' in mod['vars']['seta']['attrspec']
 
 
+class TestModuleProcedure():
+    def test_defaultPrivate(self, tmp_path):
+        f_path = tmp_path / "mod.f90"
+        with f_path.open('w') as ff:
+            ff.write(textwrap.dedent("""\
+            module foo
+              interface operator(.item.)
+                module procedure item_char, item_dict, item_dbl
+              end interface
+              interface operator(==)
+                module procedure dicts_are_equal
+              end interface
+              interface assignment(=)
+                module procedure get_value, get_integer, get_real
+              end interface
+            contains
+
+            end module foo
+            """))
+        mod = crackfortran.crackfortran([str(f_path)])
+        assert len(mod) == 1
+        mod = mod[0]
+        assert "body" in mod and len(mod["body"]) == 3
+        assert mod["body"][0]["name"] == "operator(.item.)"
+        assert "implementedby" in mod["body"][0]
+        assert mod["body"][0]["implementedby"] == \
+            ["item_char", "item_dict", "item_dbl"]
+        assert mod["body"][1]["name"] == "operator(==)"
+        assert "implementedby" in mod["body"][1]
+        assert mod["body"][1]["implementedby"] == ["dicts_are_equal"]
+        assert mod["body"][2]["name"] == "assignment(=)"
+        assert "implementedby" in mod["body"][2]
+        assert mod["body"][2]["implementedby"] == \
+            ["get_value", "get_integer", "get_real"]
+
 class TestExternal(util.F2PyTest):
     # issue gh-17859: add external attribute support
     code = """