Support PEP 380, Syntax for Delegating to a Subgenerator

PyCQA · Aug 4, 2017 · d4b17fe · d4b17fe
1 parent 08c7561
commit d4b17fe
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Showing 3 changed files with 48 additions and 2 deletions.
diff --git a/baron/grammator_primitives.py b/baron/grammator_primitives.py
@@ -69,7 +69,6 @@ def flow(pack):
 
 
     @pg.production("return_stmt : RETURN")
-    @pg.production("yield_expr : YIELD")
     def return_empty(pack):
         (token,) = pack
         return {
@@ -79,6 +78,18 @@ def return_empty(pack):
         }
 
 
+    @pg.production("yield_expr : YIELD ")
+    def yield_expr(pack):
+        (yield_,) = pack
+        return {
+            "type": yield_.name.lower(),
+            "first_formatting": [],
+            "from": None,
+            "value": None,
+            "formatting": yield_.hidden_tokens_after,
+        }
+
+
     @pg.production("break_stmt : BREAK")
     @pg.production("continue_stmt : CONTINUE")
     @pg.production("pass_stmt : PASS")
@@ -258,6 +269,18 @@ def return_testlist(pack):
             "formatting": token.hidden_tokens_after,
         }
 
+
+    @pg.production("yield_expr : YIELD FROM testlist")
+    def yield_from_expr(pack):
+        (yield_, from_, test) = pack
+        return {
+            "type": yield_.name.lower(),
+            "first_formatting": from_.hidden_tokens_after,
+            "from": True,
+            "value": test,
+            "formatting": yield_.hidden_tokens_after,
+        }
+
     @pg.production("lambdef : LAMBDA COLON test")
     @pg.production("old_lambdef : LAMBDA COLON old_test")
     def lambdef(pack):

diff --git a/baron/render.py b/baron/render.py
@@ -513,6 +513,8 @@ def child_by_key(node, key):
         "yield": [
             ("constant",   "yield",             True),
             ("formatting", "formatting",        True),
+            ("constant",   "from",              "from"),
+            ("formatting", "first_formatting",  "from"),
             ("key",        "value",             "value"),
         ],
         "yield_atom": [

diff --git a/tests/test_grammator_primitives.py b/tests/test_grammator_primitives.py
@@ -22,7 +22,28 @@ def test_yield():
     "yield"
     parse_simple([
         ('YIELD', 'yield'),
-    ], [{"type": "yield", "value": None, "formatting": [],}])
+    ], [{
+        "type": "yield",
+        "first_formatting": [],
+        "from": None,
+        "value": None,
+        "formatting": [],
+    }])
+
+
+def test_yield_from():
+    "yield from a"
+    parse_simple([
+        ('YIELD', 'yield', [], [('SPACE', ' ')]),
+        ('FROM', 'from', [], [('SPACE', ' ')]),
+        ('NAME', 'a'),
+    ], [{
+        "type": "yield",
+        "first_formatting": [{"type": "space", "value": " "}],
+        "from": True,
+        "value": {"type": "name", "value": 'a',},
+        "formatting": [{"type": "space", "value": " "}]
+    ,}])
 
 
 def test_yield_a():