From f76d4d4a7582a35e6c5bd6e96070cf45b1391aab Mon Sep 17 00:00:00 2001
From: Masataka Pocke Kuwabara <kuwabara@pocke.me>
Date: Fri, 10 Jul 2020 21:21:32 +0900
Subject: [PATCH] Make parser faster

---
 lib/rbs/parser.y | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/lib/rbs/parser.y b/lib/rbs/parser.y
index 14c56c00f..bb962f8f3 100644
--- a/lib/rbs/parser.y
+++ b/lib/rbs/parser.y
@@ -1030,6 +1030,7 @@ def initialize(type, buffer:, eof_re:)
   @eof = false
   @bound_variables_stack = []
   @comments = {}
+  @ascii_only = buffer.content.ascii_only?
 end
 
 def start_merged_variables_scope
@@ -1123,8 +1124,9 @@ def push_comment(string, location)
 end
 
 def new_token(type, value = input.matched)
-  start_index = input.charpos - input.matched.size
-  end_index = input.charpos
+  charpos = charpos(input)
+  start_index = charpos - input.matched.size
+  end_index = charpos
 
   location = RBS::Location.new(buffer: buffer,
                                            start_pos: start_index,
@@ -1133,6 +1135,14 @@ def new_token(type, value = input.matched)
   [type, LocatedValue.new(location: location, value: value)]
 end
 
+def charpos(scanner)
+  if @ascii_only
+    scanner.pos
+  else
+    scanner.charpos
+  end
+end
+
 def empty_params_result
   [
     [],
@@ -1250,8 +1260,9 @@ def next_token
     when input.scan(/\s+/)
       # skip
     when input.scan(/#(( *)|( ?(?<string>.*)))\n/)
-      start_index = input.charpos - input.matched.size
-      end_index = input.charpos-1
+      charpos = charpos(input)
+      start_index = charpos - input.matched.size
+      end_index = charpos-1
 
       location = RBS::Location.new(buffer: buffer,
                                                start_pos: start_index,