From 7611463f02f5cd82b6a41e0d58fedc6b19b29dd6 Mon Sep 17 00:00:00 2001
From: Watson <watson1978@gmail.com>
Date: Wed, 24 Aug 2022 04:23:05 +0900
Subject: [PATCH] Increase performance in Liquid::Lexer#tokenize
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To obtain String Literal, the regular expression might be executed at two times.
It would be slightly faster to run them all at once using `Regexp.union`.

−               | before   | after   | result
--               | --       | --      | --
parse            | 63.418   | 65.183  | 1.028x
render           | 195.389  | 195.648 | -
parse & render   | 46.091   | 46.917  | 1.018x

### Environment
- MacBook Pro (14 inch, 2021)
- macOS 13.0 Beta
- Apple M1 Max
- Ruby 3.1.2

### Before
```
Running benchmark for 10 seconds (with 5 seconds warmup).

Warming up --------------------------------------
              parse:     6.000  i/100ms
             render:    19.000  i/100ms
     parse & render:     4.000  i/100ms
Calculating -------------------------------------
              parse:     63.418  (± 0.0%) i/s -    636.000  in  10.028939s
             render:    195.389  (± 0.5%) i/s -      1.957k in  10.016466s
     parse & render:     46.091  (± 0.0%) i/s -    464.000  in  10.067445s
```

### After
```
Running benchmark for 10 seconds (with 5 seconds warmup).

Warming up --------------------------------------
              parse:     6.000  i/100ms
             render:    19.000  i/100ms
     parse & render:     4.000  i/100ms
Calculating -------------------------------------
              parse:     65.183  (± 0.0%) i/s -    654.000  in  10.033549s
             render:    195.648  (± 1.0%) i/s -      1.957k in  10.003511s
     parse & render:     46.917  (± 0.0%) i/s -    472.000  in  10.060782s
```
---
 lib/liquid/lexer.rb | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/lib/liquid/lexer.rb b/lib/liquid/lexer.rb
index f6205819..4ce2bc7b 100644
--- a/lib/liquid/lexer.rb
+++ b/lib/liquid/lexer.rb
@@ -18,6 +18,7 @@ module Liquid
     IDENTIFIER            = /[a-zA-Z_][\w-]*\??/
     SINGLE_STRING_LITERAL = /'[^\']*'/
     DOUBLE_STRING_LITERAL = /"[^\"]*"/
+    STRING_LITERAL        = Regexp.union(SINGLE_STRING_LITERAL, DOUBLE_STRING_LITERAL)
     NUMBER_LITERAL        = /-?\d+(\.\d+)?/
     DOTDOT                = /\.\./
     COMPARISON_OPERATOR   = /==|!=|<>|<=?|>=?|contains(?=\s)/
@@ -35,9 +36,7 @@ module Liquid
         break if @ss.eos?
         tok      = if (t = @ss.scan(COMPARISON_OPERATOR))
           [:comparison, t]
-        elsif (t = @ss.scan(SINGLE_STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(DOUBLE_STRING_LITERAL))
+        elsif (t = @ss.scan(STRING_LITERAL))
           [:string, t]
         elsif (t = @ss.scan(NUMBER_LITERAL))
           [:number, t]