commit ab5dfee240ebdbed0c1a2621c641f370b3f850c7
author Ben Clayton <bclayton@google.com> Mon Nov 09 19:52:24 2020 +0000
committer Commit Bot service account <commit-bot@chromium.org> Mon Nov 09 19:52:24 2020 +0000
tree bee401a1e2829789b991f50dfdbf0cf42a9e23c3
parent 653c4042e27643fd13838e6f619397376e6d1e77

wsgl parser: Add ParserImpl::Maybe<T>

And use it for the non-ParserImpl::expect_xxx() methods.

Another step towards supporting multiple error messages, as the caller can now test to see if the specific call errored, or didn't match, instead of using a global error state.

Makes reading the control flow conditionals a bit easier too.

Change-Id: Ie8627b8499ec9079167965da2a566401cd6bd903
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/32102
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: dan sinclair <dsinclair@chromium.org>

src/reader/wgsl/parser_impl_inclusive_or_expression_test.cc

diff --git a/src/reader/wgsl/parser_impl_inclusive_or_expression_test.cc b/src/reader/wgsl/parser_impl_inclusive_or_expression_test.cc
index e7451e7..073c2be 100644
--- a/src/reader/wgsl/parser_impl_inclusive_or_expression_test.cc
+++ b/src/reader/wgsl/parser_impl_inclusive_or_expression_test.cc
@@ -28,11 +28,13 @@
 TEST_F(ParserImplTest, InclusiveOrExpression_Parses) {
   auto* p = parser("a | true");
   auto e = p->inclusive_or_expression();
-  ASSERT_FALSE(p->has_error()) << p->error();
-  ASSERT_NE(e, nullptr);
+  EXPECT_TRUE(e.matched);
+  EXPECT_FALSE(e.errored);
+  EXPECT_FALSE(p->has_error()) << p->error();
+  ASSERT_NE(e.value, nullptr);
 
-  ASSERT_TRUE(e->IsBinary());
-  auto* rel = e->AsBinary();
+  ASSERT_TRUE(e.value->IsBinary());
+  auto* rel = e.value->AsBinary();
   EXPECT_EQ(ast::BinaryOp::kOr, rel->op());
 
   ASSERT_TRUE(rel->lhs()->IsIdentifier());
@@ -49,24 +51,30 @@
 TEST_F(ParserImplTest, InclusiveOrExpression_InvalidLHS) {
   auto* p = parser("if (a) {} | true");
   auto e = p->inclusive_or_expression();
-  ASSERT_FALSE(p->has_error()) << p->error();
-  ASSERT_EQ(e, nullptr);
+  EXPECT_FALSE(e.matched);
+  EXPECT_FALSE(e.errored);
+  EXPECT_FALSE(p->has_error()) << p->error();
+  ASSERT_EQ(e.value, nullptr);
 }
 
 TEST_F(ParserImplTest, InclusiveOrExpression_InvalidRHS) {
   auto* p = parser("true | if (a) {}");
   auto e = p->inclusive_or_expression();
-  ASSERT_TRUE(p->has_error());
-  ASSERT_EQ(e, nullptr);
+  EXPECT_FALSE(e.matched);
+  EXPECT_TRUE(e.errored);
+  EXPECT_EQ(e.value, nullptr);
+  EXPECT_TRUE(p->has_error());
   EXPECT_EQ(p->error(), "1:8: unable to parse right side of | expression");
 }
 
 TEST_F(ParserImplTest, InclusiveOrExpression_NoOr_ReturnsLHS) {
   auto* p = parser("a true");
   auto e = p->inclusive_or_expression();
-  ASSERT_FALSE(p->has_error()) << p->error();
-  ASSERT_NE(e, nullptr);
-  ASSERT_TRUE(e->IsIdentifier());
+  EXPECT_TRUE(e.matched);
+  EXPECT_FALSE(e.errored);
+  EXPECT_FALSE(p->has_error()) << p->error();
+  ASSERT_NE(e.value, nullptr);
+  ASSERT_TRUE(e.value->IsIdentifier());
 }
 
 }  // namespace