diff --git a/README.md b/README.md index 97384c0..a83ee84 100644 --- a/README.md +++ b/README.md @@ -1 +1,80 @@ # asciigoat's core library + +[![Go Reference][godoc-badge]][godoc] +[![Go Report Card][goreport-badge]][goreport] + +This package contains the basics for writing simple parsers of +text languages heavily inspired by +[Rob Pike](https://en.wikipedia.org/wiki/Rob_Pike)'s talk on +[Lexical Scanning in Go](https://go.dev/talks/2011/lex.slide#1) in 2011 which +you can [watch online](https://www.youtube.com/watch?v=HxaD_trXwRE) to get +better understanding of the ideas behind **asciigoat**. + +**asciigoat** is [MIT](https://opensource.org/license/mit/) licensed. + +[godoc]: https://pkg.go.dev/asciigoat.org/core +[godoc-badge]: https://pkg.go.dev/badge/asciigoat.org/core.svg +[goreport]: https://goreportcard.com/report/asciigoat.org/core +[goreport-badge]: https://goreportcard.com/badge/asciigoat.org/core + +[godoc-lexer-reader]: https://pkg.go.dev/asciigoat.org/core/lexer#Reader +[godoc-readcloser]: https://pkg.go.dev/asciigoat.org/core#ReadCloser + +## Lexer + +### lexer.Reader + +The lexer package provides [`lexer.Reader`][godoc-lexer-reader] which is +actually [`io.RuneScanner`](https://pkg.go.dev/io#RuneScanner) +that buffers accepted runes until you are ready to +[emit](https://pkg.go.dev/asciigoat.org/core/lexer#Reader.Emit) or +[discard](https://pkg.go.dev/asciigoat.org/core/lexer#Reader.Discard). + +### lexer.Position + +[`lexer.Position`](https://pkg.go.dev/asciigoat.org/core/lexer#Position) +is a `(Line, Column)` pair with methods to facilitate tracking +your position on the source [Reader](https://pkg.go.dev/io#Reader). +... + +### lexer.Error + +[`lexer.Error`](https://pkg.go.dev/asciigoat.org/core/lexer#Error) +is an [unwrappable](https://pkg.go.dev/errors#Unwrap) error with a +token position and hint attached. + +### lexer.StateFn + +At the heart of **asciigoat** we can _state functions_ as proposed on [Rob Pike's famous talk](https://www.youtube.com/watch?v=HxaD_trXwRE) which return the next _state function_ parsing is done. +Additionally there is a [`Run()`](https://pkg.go.dev/asciigoat.org/lexer#Run) helper that implements the loop. +... + +### rune checkers + +_Rune checkers_ are simple functions that tell if a rune is of a class or it's not. +Fundamental checkers are provided by the [`unicode` package](https://pkg.go.dev/unicode). + +Our [`lexer.Reader`][godoc-lexer-reader] uses them on its `Accept()` and `AcceptAll()` methods to +make it easier to consume the _source_ document. + +To facilitate the declaration of _rune classes_ in the context of **asciigoat** powered parsers we include +a series of rune checker factories. + +* `NewIsIn(string)` +* `NewIsInRunes(...rune)` +* `NewIsNot(checker)` +* `NewIsOneOf(...checker)` + +## Others + +### ReadCloser + +[ReadCloser][godoc-readcloser] assists in providing a +[io.Closer](https://pkg.go.dev/io#Closer) to Readers or buffers without on, +or unearthing one if available so +[io.ReadCloser](https://pkg.go.dev/io#ReadCloser) can be fulfilled. + +## See also + +* [asciigoat.org/ini](https://asciigoat.org/ini) +* [oss.jpi.io](https://oss.jpi.io)