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.

2 files changed, 69 insertions, 0 deletions

diff --git a/numpy/f2py/tests/src/crackfortran/operators.f90 b/numpy/f2py/tests/src/crackfortran/operators.f90
new file mode 100644
index 000000000..1d060a3d2
--- /dev/null
+++ b/numpy/f2py/tests/src/crackfortran/operators.f90
@@ -0,0 +1,49 @@
+module foo
+  type bar
+     character(len = 32) :: item
+  end type bar
+  interface operator(.item.)
+     module procedure item_int, item_real
+  end interface operator(.item.)
+  interface operator(==)
+     module procedure items_are_equal
+  end interface operator(==)
+  interface assignment(=)
+     module procedure get_int, get_real
+  end interface assignment(=)
+contains
+  function item_int(val) result(elem)
+    integer, intent(in) :: val
+    type(bar) :: elem
+
+    write(elem%item, "(I32)") val
+  end function item_int
+
+  function item_real(val) result(elem)
+    real, intent(in) :: val
+    type(bar) :: elem
+
+    write(elem%item, "(1PE32.12)") val
+  end function item_real
+
+  function items_are_equal(val1, val2) result(equal)
+    type(bar), intent(in) :: val1, val2
+    logical :: equal
+
+    equal = (val1%item == val2%item)
+  end function items_are_equal
+
+  subroutine get_real(rval, item)
+    real, intent(out) :: rval
+    type(bar), intent(in) :: item
+
+    read(item%item, *) rval
+  end subroutine get_real
+
+  subroutine get_int(rval, item)
+    integer, intent(out) :: rval
+    type(bar), intent(in) :: item
+
+    read(item%item, *) rval
+  end subroutine get_int
+end module foo
diff --git a/numpy/f2py/tests/test_crackfortran.py b/numpy/f2py/tests/test_crackfortran.py
index fb47eb31d..e33e12d62 100644
--- a/numpy/f2py/tests/test_crackfortran.py
+++ b/numpy/f2py/tests/test_crackfortran.py
@@ -45,6 +45,26 @@ class TestPublicPrivate:
         assert "public" in mod["vars"]["seta"]["attrspec"]
 
 
+class TestModuleProcedure():
+    def test_moduleOperators(self, tmp_path):
+        fpath = util.getpath("tests", "src", "crackfortran", "operators.f90")
+        mod = crackfortran.crackfortran([str(fpath)])
+        assert len(mod) == 1
+        mod = mod[0]
+        assert "body" in mod and len(mod["body"]) == 9
+        assert mod["body"][1]["name"] == "operator(.item.)"
+        assert "implementedby" in mod["body"][1]
+        assert mod["body"][1]["implementedby"] == \
+            ["item_int", "item_real"]
+        assert mod["body"][2]["name"] == "operator(==)"
+        assert "implementedby" in mod["body"][2]
+        assert mod["body"][2]["implementedby"] == ["items_are_equal"]
+        assert mod["body"][3]["name"] == "assignment(=)"
+        assert "implementedby" in mod["body"][3]
+        assert mod["body"][3]["implementedby"] == \
+            ["get_int", "get_real"]
+
+
 class TestExternal(util.F2PyTest):
     # issue gh-17859: add external attribute support
     sources = [util.getpath("tests", "src", "crackfortran", "gh17859.f")]