Implement syntax sugar for optional else, closes #11

google · Aug 12, 2014 · 73ce797 · 73ce797
1 parent 291c3e6
commit 73ce797
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/parser.cpp b/parser.cpp
@@ -578,8 +578,13 @@ namespace {
                     AST *cond = parse(MAX_PRECEDENCE, obj_level);
                     popExpect(Token::THEN);
                     AST *branch_true = parse(MAX_PRECEDENCE, obj_level);
-                    popExpect(Token::ELSE);
-                    AST *branch_false = parse(MAX_PRECEDENCE, obj_level);
+                    AST *branch_false;
+                    if (peek().kind == Token::ELSE) {
+                        pop();
+                        branch_false = parse(MAX_PRECEDENCE, obj_level);
+                    } else {
+                        branch_false = alloc.make<LiteralNull>(span(begin, branch_true));
+                    }
                     return alloc.make<Conditional>(span(begin, branch_false),
                                                    cond, branch_true, branch_false);
                 }

diff --git a/test_suite/condition.jsonnet b/test_suite/condition.jsonnet
@@ -31,5 +31,7 @@ std.assertEqual(f(0), "zero") &&
 std.assertEqual(f(3), "small") &&
 std.assertEqual(f(8), "large") &&
 std.assertEqual(f(100), "huge") &&
+std.assertEqual(if 1 > 0 then 1, 1) &&
+std.assertEqual(if 1 > 2 then 1, null) &&
 
 true