Viewing github.com/alecthomas/chroma/lexers/go.go

```
package lexers
```
```
import (
```
```
	"strings"
```

	. "github.com/alecthomas/chroma/v2" // nolint

```
)
```
```
// Go lexer.
```
```
var Go = Register(MustNewLexer(
```
```
	&Config{
```
```
		Name:      "Go",
```
```
		Aliases:   []string{"go", "golang"},
```
```
		Filenames: []string{"*.go"},
```
```
		MimeTypes: []string{"text/x-gosrc"},
```
```
		EnsureNL:  true,
```
```
	},
```
```
	goRules,
```

).SetAnalyser(func(text string) float32 {

	if strings.Contains(text, "fmt.") && strings.Contains(text, "package ") {

```
		return 0.5
```
```
	}
```

	if strings.Contains(text, "package ") {

```
		return 0.1
```
```
	}
```
```
	return 0.0
```
```
}))
```
```
func goRules() Rules {
```
```
	return Rules{
```
```
		"root": {
```
```
			{`\n`, Text, nil},
```
```
			{`\s+`, Text, nil},
```
```
			{`\\\n`, Text, nil},
```
```
			{`//(.*?)\n`, CommentSingle, nil},
```

			{`/(\\\n)?[*](.|\n)*?[*](\\\n)?/`, CommentMultiline, nil},

			{`(import|package)\b`, KeywordNamespace, nil},

			{`(var|func|struct|map|chan|type|interface|const)\b`, KeywordDeclaration, nil},

			{Words(``, `\b`, `break`, `default`, `select`, `case`, `defer`, `go`, `else`, `goto`, `switch`, `fallthrough`, `if`, `range`, `continue`, `for`, `return`), Keyword, nil},

			{`(true|false|iota|nil)\b`, KeywordConstant, nil},

			{Words(``, `\b(\()`, `uint`, `uint8`, `uint16`, `uint32`, `uint64`, `int`, `int8`, `int16`, `int32`, `int64`, `float`, `float32`, `float64`, `complex64`, `complex128`, `byte`, `rune`, `string`, `bool`, `error`, `uintptr`, `print`, `println`, `panic`, `recover`, `close`, `complex`, `real`, `imag`, `len`, `cap`, `append`, `copy`, `delete`, `new`, `make`, `clear`, `min`, `max`), ByGroups(NameBuiltin, Punctuation), nil},

			{Words(``, `\b`, `uint`, `uint8`, `uint16`, `uint32`, `uint64`, `int`, `int8`, `int16`, `int32`, `int64`, `float`, `float32`, `float64`, `complex64`, `complex128`, `byte`, `rune`, `string`, `bool`, `error`, `uintptr`), KeywordType, nil},

```
			{`\d+i`, LiteralNumber, nil},
```

			{`\d+\.\d*([Ee][-+]\d+)?i`, LiteralNumber, nil},

			{`\.\d+([Ee][-+]\d+)?i`, LiteralNumber, nil},

			{`\d+[Ee][-+]\d+i`, LiteralNumber, nil},

			{`\d+(\.\d+[eE][+\-]?\d+|\.\d*|[eE][+\-]?\d+)`, LiteralNumberFloat, nil},

			{`\.\d+([eE][+\-]?\d+)?`, LiteralNumberFloat, nil},

```
			{`0[0-7]+`, LiteralNumberOct, nil},
```

			{`0[xX][0-9a-fA-F_]+`, LiteralNumberHex, nil},

			{`0b[01_]+`, LiteralNumberBin, nil},

			{`(0|[1-9][0-9_]*)`, LiteralNumberInteger, nil},

			{`'(\\['"\\abfnrtv]|\\x[0-9a-fA-F]{2}|\\[0-7]{1,3}|\\u[0-9a-fA-F]{4}|\\U[0-9a-fA-F]{8}|[^\\])'`, LiteralStringChar, nil},

			{"(`)([^`]*)(`)", ByGroups(LiteralString, UsingLexer(TypeRemappingLexer(GoTextTemplate, TypeMapping{{Other, LiteralString, nil}})), LiteralString), nil},

			{`"(\\\\|\\"|[^"])*"`, LiteralString, nil},

			{`(<<=|>>=|<<|>>|<=|>=|&\^=|&\^|\+=|-=|\*=|/=|%=|&=|\|=|&&|\|\||<-|\+\+|--|==|!=|:=|\.\.\.|[+\-*/%&])`, Operator, nil},

			{`([a-zA-Z_]\w*)(\s*)(\()`, ByGroups(NameFunction, UsingSelf("root"), Punctuation), nil},

			{`[|^<>=!()\[\]{}.,;:]`, Punctuation, nil},

```
			{`[^\W\d]\w*`, NameOther, nil},
```
```
		},
```
```
	}
```
```
}
```

var GoHTMLTemplate = Register(DelegatingLexer(HTML, MustNewXMLLexer(

```
	embedded,
```
```
	"embedded/go_template.xml",
```
```
).SetConfig(
```
```
	&Config{
```
```
		Name:    "Go HTML Template",
```

		Aliases: []string{"go-html-template"},

```
	},
```
```
)))
```

var GoTextTemplate = Register(MustNewXMLLexer(

```
	embedded,
```
```
	"embedded/go_template.xml",
```
```
).SetConfig(
```
```
	&Config{
```
```
		Name:    "Go Text Template",
```

		Aliases: []string{"go-text-template"},

```
	},
```
```
))
```