chroma/lexers/html.go

package lexers

import (
	"github.com/alecthomas/chroma/v2"
)

// HTML lexer.
var HTML = chroma.MustNewXMLLexer(embedded, "embedded/html.xml")
Version 2 of Chroma This cleans up the API in general, removing a bunch of deprecated stuff, cleaning up circular imports, etc. But the biggest change is switching to an optional XML format for the regex lexer. Having lexers defined only in Go is not ideal for a couple of reasons. Firstly, it impedes a significant portion of contributors who use Chroma in Hugo, but don't know Go. Secondly, it bloats the binary size of any project that imports Chroma. Why XML? YAML is an abomination and JSON is not human editable. XML also compresses very well (eg. Go template lexer XML compresses from 3239 bytes to 718). Why a new syntax format? All major existing formats rely on the Oniguruma regex engine, which is extremely complex and for which there is no Go port. Why not earlier? Prior to the existence of fs.FS this was not a viable option. Benchmarks: $ hyperfine --warmup 3 \ './chroma.master --version' \ './chroma.xml-pre-opt --version' \ './chroma.xml --version' Benchmark 1: ./chroma.master --version Time (mean ± σ): 5.3 ms ± 0.5 ms [User: 3.6 ms, System: 1.4 ms] Range (min … max): 4.2 ms … 6.6 ms 233 runs Benchmark 2: ./chroma.xml-pre-opt --version Time (mean ± σ): 50.6 ms ± 0.5 ms [User: 52.4 ms, System: 3.6 ms] Range (min … max): 49.2 ms … 51.5 ms 51 runs Benchmark 3: ./chroma.xml --version Time (mean ± σ): 6.9 ms ± 1.1 ms [User: 5.1 ms, System: 1.5 ms] Range (min … max): 5.7 ms … 19.9 ms 196 runs Summary './chroma.master --version' ran 1.30 ± 0.23 times faster than './chroma.xml --version' 9.56 ± 0.83 times faster than './chroma.xml-pre-opt --version' A slight increase in init time, but I think this is okay given the increase in flexibility. And binary size difference: $ du -h lexers.test* $ du -sh chroma* 951371ms 8.8M chroma.master 7.8M chroma.xml 7.8M chroma.xml-pre-opt Benchmarks: $ hyperfine --warmup 3 \ './chroma.master --version' \ './chroma.xml-pre-opt --version' \ './chroma.xml --version' Benchmark 1: ./chroma.master --version Time (mean ± σ): 5.3 ms ± 0.5 ms [User: 3.6 ms, System: 1.4 ms] Range (min … max): 4.2 ms … 6.6 ms 233 runs Benchmark 2: ./chroma.xml-pre-opt --version Time (mean ± σ): 50.6 ms ± 0.5 ms [User: 52.4 ms, System: 3.6 ms] Range (min … max): 49.2 ms … 51.5 ms 51 runs Benchmark 3: ./chroma.xml --version Time (mean ± σ): 6.9 ms ± 1.1 ms [User: 5.1 ms, System: 1.5 ms] Range (min … max): 5.7 ms … 19.9 ms 196 runs Summary './chroma.master --version' ran 1.30 ± 0.23 times faster than './chroma.xml --version' 9.56 ± 0.83 times faster than './chroma.xml-pre-opt --version' Incompatible changes: - (RegexLexer).SetAnalyser: changed from func(func(text string) float32) RegexLexer to func(func(text string) float32) Lexer - (TokenType).UnmarshalJSON: removed - Lexer.AnalyseText: added - Lexer.SetAnalyser: added - Lexer.SetRegistry: added - MustNewLazyLexer: removed - MustNewLexer: changed from func(Config, Rules) RegexLexer to func(Config, func() Rules) RegexLexer - Mutators: changed from func(...Mutator) MutatorFunc to func(...Mutator) Mutator - NewLazyLexer: removed - NewLexer: changed from func(Config, Rules) (RegexLexer, error) to func(Config, func() Rules) (*RegexLexer, error) - Pop: changed from func(int) MutatorFunc to func(int) Mutator - Push: changed from func(...string) MutatorFunc to func(...string) Mutator - TokenType.MarshalJSON: removed - Using: changed from func(Lexer) Emitter to func(string) Emitter - UsingByGroup: changed from func(func(string) Lexer, int, int, ...Emitter) Emitter to func(int, int, ...Emitter) Emitter 2022-01-03 23:51:17 +11:00			`package lexers`
Imported: css, html, java, php. 2017-06-05 11:14:54 +10:00
			`import (`
refactor: migrate a bunch more Go-based lexers to XML Also rename some existing XML lexers to their canonical XML name. 2023-09-09 12:29:23 +10:00			`"github.com/alecthomas/chroma/v2"`
Imported: css, html, java, php. 2017-06-05 11:14:54 +10:00			`)`

Fixes: css, html, php. 2017-06-05 11:17:38 +10:00			`// HTML lexer.`
refactor: migrate a bunch more Go-based lexers to XML Also rename some existing XML lexers to their canonical XML name. 2023-09-09 12:29:23 +10:00			`var HTML = chroma.MustNewXMLLexer(embedded, "embedded/html.xml")`