move the usages stuff away from dynamic

jedi/api.py

@@ -700,3 +700,83 @@ def set_debug_function(func_cb=debug.print_to_stdout, warnings=True,
     debug.enable_warning = warnings
     debug.enable_notice = notices
     debug.enable_speed = speed
+
+
+# TODO move to a better place.
+def usages(definitions, search_name, mods):
+    def compare_array(definitions):
+        """ `definitions` are being compared by module/start_pos, because
+        sometimes the id's of the objects change (e.g. executions).
+        """
+        result = []
+        for d in definitions:
+            module = d.get_parent_until()
+            result.append((module, d.start_pos))
+        return result
+
+    def check_call(call):
+        result = []
+        follow = []  # There might be multiple search_name's in one call_path
+        call_path = list(call.generate_call_path())
+        for i, name in enumerate(call_path):
+            # name is `pr.NamePart`.
+            if name == search_name:
+                follow.append(call_path[:i + 1])
+
+        for f in follow:
+            follow_res, search = evaluate.goto(call.parent, f)
+            follow_res = usages_add_import_modules(follow_res, search)
+
+            compare_follow_res = compare_array(follow_res)
+            # compare to see if they match
+            if any(r in compare_definitions for r in compare_follow_res):
+                scope = call.parent
+                result.append(api_classes.Usage(search, scope))
+
+        return result
+
+    if not definitions:
+        return set()
+
+    compare_definitions = compare_array(definitions)
+    mods |= set([d.get_parent_until() for d in definitions])
+    names = []
+    for m in get_directory_modules_for_name(mods, search_name):
+        try:
+            stmts = m.used_names[search_name]
+        except KeyError:
+            continue
+        for stmt in stmts:
+            if isinstance(stmt, pr.Import):
+                count = 0
+                imps = []
+                for i in stmt.get_all_import_names():
+                    for name_part in i.names:
+                        count += 1
+                        if name_part == search_name:
+                            imps.append((count, name_part))
+
+                for used_count, name_part in imps:
+                    i = imports.ImportPath(_evaluator, stmt, kill_count=count - used_count,
+                                           direct_resolve=True)
+                    f = i.follow(is_goto=True)
+                    if set(f) & set(definitions):
+                        names.append(api_classes.Usage(name_part, stmt))
+            else:
+                for call in _scan_statement(stmt, search_name,
+                                            assignment_details=True):
+                    names += check_call(call)
+    return names
+
+
+def usages_add_import_modules(definitions, search_name):
+    """ Adds the modules of the imports """
+    new = set()
+    for d in definitions:
+        if isinstance(d.parent, pr.Import):
+            s = imports.ImportPath(_evaluator, d.parent, direct_resolve=True)
+            with common.ignored(IndexError):
+                new.add(s.follow(is_goto=True)[0])
+    return set(definitions) | new
+
+