add http lexer

lexers/http.go

@@ -0,0 +1,101 @@
+package lexers
+
+import (
+	. "github.com/alecthomas/chroma" // nolint
+	"strings"
+)
+
+var httpBodyContentType string
+
+// Http lexer.
+var Http = Register(MustNewLexer(
+	&Config{
+		Name:         "HTTP",
+		Aliases:      []string{"http"},
+		Filenames:    []string{},
+		MimeTypes:    []string{},
+		NotMultiline: true,
+		DotAll:       true,
+	},
+	Rules{
+		"root": {
+			{`(GET|POST|PUT|DELETE|HEAD|OPTIONS|TRACE|PATCH)( +)([^ ]+)( +)(HTTP)(/)(1\.[01])(\r?\n|\Z)`, ByGroups(NameFunction, Text, NameNamespace, Text, KeywordReserved, Operator, LiteralNumber, Text), Push("headers")},
+			{`(HTTP)(/)(1\.[01])( +)(\d{3})( +)([^\r\n]+)(\r?\n|\Z)`, ByGroups(KeywordReserved, Operator, LiteralNumber, Text, LiteralNumber, Text, NameException, Text), Push("headers")},
+		},
+		"headers": {
+			{`([^\s:]+)( *)(:)( *)([^\r\n]+)(\r?\n|\Z)`, EmitterFunc(httpHeaderBlock), nil},
+			{`([\t ]+)([^\r\n]+)(\r?\n|\Z)`, EmitterFunc(httpContinuousHeaderBlock), nil},
+			{`\r?\n`, Text, Push("content")},
+		},
+		"content": {
+			{`.+`, EmitterFunc(httpContentBlock), nil},
+		},
+	},
+))
+
+func httpContentBlock(groups []string, lexer Lexer) Iterator {
+	iterators := []Iterator{}
+	code := groups[0]
+
+	if len(httpBodyContentType) > 0 {
+		lexer := MatchMimeType(httpBodyContentType)
+
+		// application/calendar+xml can be treated as application/xml
+		// if there's not a better match.
+		if lexer == nil && strings.Contains(httpBodyContentType, "+") {
+			slashPos := strings.Index(httpBodyContentType, "/")
+			plusPos := strings.LastIndex(httpBodyContentType, "+")
+			httpBodyContentType = httpBodyContentType[:slashPos+1] + httpBodyContentType[plusPos+1:]
+			lexer = MatchMimeType(httpBodyContentType)
+		}
+
+		if lexer != nil {
+			sub, err := lexer.Tokenise(nil, code)
+			if err != nil {
+				panic(err)
+			}
+			iterators = append(iterators, sub)
+		} else {
+			tokens := []*Token{
+				{Text, code},
+			}
+			iterators = append(iterators, Literator(tokens...))
+		}
+	}
+	return Concaterator(iterators...)
+}
+
+func httpHeaderBlock(groups []string, lexer Lexer) Iterator {
+	if strings.ToLower(groups[1]) == "content-type" {
+		contentType := strings.TrimSpace(groups[5])
+		pos := strings.Index(contentType, ";")
+		if pos > 0 {
+			contentType = strings.TrimSpace(contentType[:pos])
+		}
+
+		httpBodyContentType = contentType
+	}
+
+	iterators := []Iterator{}
+	tokens := []*Token{
+		{Name, groups[1]},
+		{Text, groups[2]},
+		{Operator, groups[3]},
+		{Text, groups[4]},
+		{Literal, groups[5]},
+		{Text, groups[6]},
+	}
+	iterators = append(iterators, Literator(tokens...))
+	return Concaterator(iterators...)
+}
+
+func httpContinuousHeaderBlock(groups []string, lexer Lexer) Iterator {
+	iterators := []Iterator{}
+	tokens := []*Token{
+		{Text, groups[1]},
+		{Literal, groups[2]},
+		{Text, groups[3]},
+	}
+	iterators = append(iterators, Literator(tokens...))
+	return Concaterator(iterators...)
+}