Merge pull request #462 from adrian17/lambda_parsing

Change lambda parsing to be closer to Python official grammar. Fixes #427

parser/src/python.lalrpop

@@ -663,7 +663,7 @@ Test: ast::Expression = {
 };
 
 LambdaDef: ast::Expression = {
-    "lambda" <p:TypedArgsList?> ":" <b:Expression> =>
+    "lambda" <p:TypedArgsList?> ":" <b:Test> =>
         ast::Expression::Lambda {
             args: p.unwrap_or(Default::default()),
             body:Box::new(b)

tests/snippets/funky_syntax.py

@@ -5,4 +5,10 @@ assert b == 6
 c = 2 + 4 if a > 5 else 'boe'
 assert c == 'boe'
 
+d = lambda x, y: x > y
+assert d(5, 4)
+
+e = lambda x: 1 if x else 0
+assert e(True) == 1
+assert e(False) == 0