quasilyte / parsing-and-go

Parsing & Go

This repository provides examples I referred to in "Parsing & Go" talk

Parsing phpdoc type expressions using several approaches:

• participle example uses alecthomas/participle with default lexer
• yacc example uses goyacc with text/scanner for lexing
• yacc_ragel example uses goyacc with a lexer generated with Ragel
• handwritten example shows a manually created parser from NoVerify static analyzer

These example parsers understand these types (and their combinations):

Type	Example
primitive type	int, float, null, ...
type name	Foo, Foo\Bar
nullable type	?T
optional key type	T?
array type	T[]
union type	X|Y
intersection type	X&Y

Package phpdoc defines the common AST constructed by every parser.

Package phpdoctest contains test cases that are used to test every parser.

Every parser package is a main that can parse a command-line argument:

go run ./participle 'int|Foo\Bar'

go run ./yacc 'int|Foo\Bar'

go run ./yacc_ragel 'int|Foo\Bar'

go run ./handwritten 'int|Foo\Bar'

Some useful make commands:

# build all parsers (requires goyacc and ragel installed)
make all

# run all tests
make test

# run all benchmarks
make bench