A work in progress improvement for compiled signatures

jedi/evaluate/compiled/access.py

@@ -377,6 +377,21 @@ class DirectObjectAccess(object):
         return inspect.isclass(self._obj) and self._obj != type
 
     def get_signature_params(self):
+        return [
+            SignatureParam(
+                name=p.name,
+                has_default=p.default is not p.empty,
+                default=self._create_access_path(p.default),
+                has_annotation=p.annotation is not p.empty,
+                annotation=self._create_access_path(p.annotation),
+                kind_name=str(p.kind)
+            ) for p in self._get_signature().parameters.values()
+        ]
+
+    def get_signature_text(self):
+        return str(self._get_signature())
+
+    def _get_signature(self):
         obj = self._obj
         if py_version < 33:
             raise ValueError("inspect.signature was introduced in 3.3")
@@ -397,22 +412,12 @@ class DirectObjectAccess(object):
                 raise ValueError
 
         try:
-            signature = inspect.signature(obj)
+            return inspect.signature(obj)
         except (RuntimeError, TypeError):
             # Reading the code of the function in Python 3.6 implies there are
             # at least these errors that might occur if something is wrong with
             # the signature. In that case we just want a simple escape for now.
             raise ValueError
-        return [
-            SignatureParam(
-                name=p.name,
-                has_default=p.default is not p.empty,
-                default=self._create_access_path(p.default),
-                has_annotation=p.annotation is not p.empty,
-                annotation=self._create_access_path(p.annotation),
-                kind_name=str(p.kind)
-            ) for p in signature.parameters.values()
-        ]
 
     def negate(self):
         return self._create_access_path(-self._obj)

jedi/evaluate/compiled/context.py

@@ -5,6 +5,7 @@ import re
 from functools import partial
 
 from jedi import debug
+from jedi.evaluate.utils import to_list
 from jedi._compatibility import force_unicode, Parameter, cast_path
 from jedi.cache import underscore_memoization, memoize_method
 from jedi.evaluate.filters import AbstractFilter
@@ -111,6 +112,7 @@ class CompiledObject(Context):
     def py__doc__(self):
         return self.access_handle.py__doc__()
 
+    @to_list
     def get_param_names(self):
         try:
             signature_params = self.access_handle.get_signature_params()
@@ -126,6 +128,13 @@ class CompiledObject(Context):
             for signature_param in signature_params:
                 yield SignatureParamName(self, signature_param)
 
+    def get_signature_text(self):
+        try:
+            return self.access_handle.get_signature_text()
+        except ValueError:
+            params_str, ret = self._parse_function_doc()
+            return '(' + params_str + ')' + ret
+
     def get_signatures(self):
         return [BuiltinSignature(self)]