Sloppy-mode let parsing

src/scanner.h

Index: src/scanner.h
diff --git a/src/scanner.h b/src/scanner.h
index 92588905ad609b7ea64d8c5c7c2007d3e55d409b..393f0a0981f7853f4a9a84c7559899ae9e311489 100644
--- a/src/scanner.h
+++ b/src/scanner.h
@@ -399,6 +399,8 @@ class Scanner {
 
   // Returns the next token and advances input.
   Token::Value Next();
+  // Returns the token following peek()
+  Token::Value PeekAhead();
   // Returns the current token again.
   Token::Value current_token() { return current_.token; }
   // Returns the location information for the current token
@@ -527,6 +529,8 @@ class Scanner {
     // Initialize current_ to not refer to a literal.
     current_.literal_chars = NULL;
     current_.raw_literal_chars = NULL;
+    uber_next_.token = Token::UNINITIALIZED;
+    prev_.token = Token::UNINITIALIZED;
   }
 
   // Support BookmarkScope functionality.
@@ -539,16 +543,23 @@ class Scanner {
 
   // Literal buffer support
   inline void StartLiteral() {
-    LiteralBuffer* free_buffer = (current_.literal_chars == &literal_buffer1_) ?
-            &literal_buffer2_ : &literal_buffer1_;
+    LiteralBuffer* free_buffer =
+        (current_.literal_chars == &literal_buffers_[0])

[adamk, 2015/08/15 00:28:31]

Why switch to using an array for this? The advantage of separate names is that a
typo is a compile-time error, instead of an OOB access at runtime. I'd prefer to
go back unless there's a particular need for using an array.

[adamk, 2015/08/17 18:24:39]

I didn't see this addressed in the latest patch.

[Dan Ehrenberg, 2015/08/17 18:35:19]

Oops, fixed.

+            ? &literal_buffers_[1]
+            : (current_.literal_chars == &literal_buffers_[1])
+                  ? &literal_buffers_[2]
+                  : &literal_buffers_[0];
     free_buffer->Reset();
     next_.literal_chars = free_buffer;
   }
 
   inline void StartRawLiteral() {
     LiteralBuffer* free_buffer =
-        (current_.raw_literal_chars == &raw_literal_buffer1_) ?
-            &raw_literal_buffer2_ : &raw_literal_buffer1_;
+        (current_.raw_literal_chars == &raw_literal_buffers_[0])
+            ? &raw_literal_buffers_[1]
+            : (current_.raw_literal_chars == &raw_literal_buffers_[1])
+                  ? &raw_literal_buffers_[2]
+                  : &raw_literal_buffers_[0];
     free_buffer->Reset();
     next_.raw_literal_chars = free_buffer;
   }
@@ -725,19 +736,19 @@ class Scanner {
   UnicodeCache* unicode_cache_;
 
   // Buffers collecting literal strings, numbers, etc.
-  LiteralBuffer literal_buffer1_;
-  LiteralBuffer literal_buffer2_;
+  LiteralBuffer literal_buffers_[3];
 
   // Values parsed from magic comments.
   LiteralBuffer source_url_;
   LiteralBuffer source_mapping_url_;
 
   // Buffer to store raw string values
-  LiteralBuffer raw_literal_buffer1_;
-  LiteralBuffer raw_literal_buffer2_;
+  LiteralBuffer raw_literal_buffers_[3];
 
-  TokenDesc current_;  // desc for current token (as returned by Next())
-  TokenDesc next_;     // desc for next token (one token look-ahead)
+  TokenDesc current_;    // desc for current token (as returned by Next())
+  TokenDesc next_;       // desc for next token (one token look-ahead)
+  TokenDesc uber_next_;  // desc for the token after next (push-back)

[adamk, 2015/08/15 00:28:31]

I think "next_next_" is clearer in English. That's my vote for a name unless
Andreas has a better idea.

+  TokenDesc prev_;       // desc for the previous token (stash for pushback)
 
   // Variables for Scanner::BookmarkScope and the *Bookmark implementation.
   // These variables contain the scanner state when a bookmark is set.