Faster #charpos

Steepfile

@@ -5,6 +5,7 @@ target :lib do
   ignore "lib/rbs/prototype", "lib/rbs/test", "lib/rbs/test.rb"
 
   library "set", "pathname", "json", "logger", "monitor", "tsort"
+  signature "stdlib/strscan/0/"
 end
 
 # target :lib do

bin/rbs-prof

@@ -4,6 +4,6 @@ require "stackprof"
 
 out = ENV["RBS_STACKPROF_OUT"] || 'tmp/stackprof-cpu-rbs.dump'
 
-StackProf.run(mode: :cpu, out: out) do
+StackProf.run(mode: :cpu, out: out, raw: true) do
   load File.join(__dir__, "../exe/rbs")
 end

lib/rbs.rb

@@ -7,7 +7,9 @@
 require "ripper"
 require "logger"
 require "tsort"
+require "strscan"
 
+require "rbs/char_scanner"
 require "rbs/errors"
 require "rbs/buffer"
 require "rbs/location"

lib/rbs/char_scanner.rb

@@ -0,0 +1,20 @@
+module RBS
+  class CharScanner < StringScanner
+    def initialize(string)
+      super(string)
+      @charpos = 0
+    end
+
+    alias original_charpos charpos
+
+    def charpos
+      @charpos
+    end
+
+    def scan(pattern)
+      s = super
+      @charpos += s.size if s
+      s
+    end
+  end
+end

lib/rbs/parser.y

@@ -1088,8 +1088,6 @@ class LocatedValue
   end
 end
 
-require "strscan"
-
 attr_reader :input
 attr_reader :buffer
 attr_reader :eof_re
@@ -1098,7 +1096,7 @@ def initialize(type, buffer:, eof_re:)
   super()
   @type = type
   @buffer = buffer
-  @input = StringScanner.new(buffer.content)
+  @input = CharScanner.new(buffer.content)
   @eof_re = eof_re
   @eof = false
   @bound_variables_stack = []
@@ -1214,11 +1212,7 @@ def new_token(type, value = input.matched)
 end
 
 def charpos(scanner)
-  if @ascii_only
-    scanner.pos
-  else
-    scanner.charpos
-  end
+  scanner.charpos
 end
 
 def empty_params_result

sig/char_scanner.rbs

@@ -0,0 +1,9 @@
+module RBS
+  class CharScanner < StringScanner
+    def initialize: (String) -> void
+
+    def original_charpos: () -> Integer
+
+    @charpos: Integer
+  end
+end