Files
liquid/lib/liquid/lexer.rb
T
Watson 7611463f02 Increase performance in Liquid::Lexer#tokenize
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
```
2022-08-24 04:23:05 +09:00

62 lines
1.5 KiB
Ruby

# frozen_string_literal: true
require "strscan"
module Liquid
class Lexer
SPECIALS = {
'|' => :pipe,
'.' => :dot,
':' => :colon,
',' => :comma,
'[' => :open_square,
']' => :close_square,
'(' => :open_round,
')' => :close_round,
'?' => :question,
'-' => :dash,
}.freeze
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)/
WHITESPACE_OR_NOTHING = /\s*/
def initialize(input)
@ss = StringScanner.new(input)
end
def tokenize
@output = []
until @ss.eos?
@ss.skip(WHITESPACE_OR_NOTHING)
break if @ss.eos?
tok = if (t = @ss.scan(COMPARISON_OPERATOR))
[:comparison, t]
elsif (t = @ss.scan(STRING_LITERAL))
[:string, t]
elsif (t = @ss.scan(NUMBER_LITERAL))
[:number, t]
elsif (t = @ss.scan(IDENTIFIER))
[:id, t]
elsif (t = @ss.scan(DOTDOT))
[:dotdot, t]
else
c = @ss.getch
if (s = SPECIALS[c])
[s, c]
else
raise SyntaxError, "Unexpected character #{c}"
end
end
@output << tok
end
@output << [:end_of_string]
end
end
end