| perl bench.pl /usr/share/iso-codes/json/iso_639-3.json | |
| Using /usr/share/iso-codes/json/iso_639-3.json | |
| Using Marpa::R2 8 | |
| (warning: too few iterations for a reliable count) | |
| (warning: too few iterations for a reliable count) | |
| (warning: too few iterations for a reliable count) | |
| s/iter ESLIF JSON SLIF JSON JSON::PP JSON::XS | |
| ESLIF JSON 7.43 -- -10% -71% -100% | |
| SLIF JSON 6.68 11% -- -68% -100% | |
| JSON::PP 2.13 249% 214% -- -99% |
| make basic | |
| perl bench.pl test.json | |
| Using test.json | |
| Using Marpa::R2 8 | |
| Rate SLIF JSON JSON::PP ESLIF JSON JSON::XS | |
| SLIF JSON 107/s -- -71% -76% -100% | |
| JSON::PP 366/s 241% -- -18% -99% | |
| ESLIF JSON 449/s 318% 23% -- -99% | |
| JSON::XS 38642/s 35944% 10465% 8514% -- |
The post An Overview Of The Marpa Parser was originally published at https://lukasatkinson.de/2015/marpa-overview/.
Parsing pervades all of computing. Whenever we are dealing with some data format or a programming language, something needs to parse that. But writing a good grammar for a given language, and picking a suitable parser is not always easy.
For example, let's look at some strings in an example language:
| #!perl | |
| use strict; | |
| use warnings; | |
| use 5.010; | |
| use Data::Dumper; | |
| use Marpa::R2; | |
| sub My_Actions::dwim { | |
| shift; | |
| return $_[0] if scalar @_ == 1; |
| #!perl | |
| use strict; | |
| use warnings; | |
| use 5.010; | |
| use Data::Dumper; | |
| use Marpa::R2; | |
| sub My_Actions::dwim { | |
| shift; | |
| return $_[0] if scalar @_ == 1; |
| #!perl | |
| use strict; | |
| use warnings; | |
| use 5.010; | |
| use Data::Dumper; | |
| use Marpa::R2; | |
| sub My_Actions::dwim { | |
| shift; | |
| return $_[0] if scalar @_ == 1; |
| #!perl | |
| use strict; | |
| use warnings; | |
| use 5.010; | |
| use Data::Dumper; | |
| use Marpa::R2; | |
| # This grammar tries to be equivalent to a PEG or Regex with ordered choice: | |
| # List: Item* | |
| # Item: VAR = VAR // VAR = // VAR |
| \datethis | |
| @*Intro. This program generates clauses for the transition relation | |
| from time $t$ to time $t+1$ in Conway's Game of Life, assuming that | |
| all of the potentially live cells at time $t$ belong to a pattern | |
| that's specified in |stdin|. The pattern is defined by one or more | |
| lines representing rows of cells, where each line has `\..' in a | |
| cell that's guaranteed to be dead at time~$t$, otherwise it has `\.*'. | |
| The time is specified separately as a command-line parameter. | |
| The Boolean variable for cell $(x,y)$ at time $t$ is named by its |
| #!/usr/bin/perl | |
| use 5.010; | |
| use strict; | |
| use warnings; | |
| use Data::Dumper; | |
| use English qw( -no_match_vars ); | |
| use Test::More tests => 6; |
| DSL: | |
| :default ::= action => [values] bless => ::lhs | |
| lexeme default = action => [ start, length, value ] | |
| bless => ::name latm => 1 | |
| :start ::= Script | |
| Script ::= Expression+ separator => comma | |
| comma ~ [,] | |
| Expression ::= | |
| Number bless => primary |