Add Objective-C and support lexer priorities.

Fixes #66.

lexer.go

@@ -50,6 +50,11 @@ type Config struct {
 
 	// If given and greater than 0, expand tabs in the input.
 	// TabSize int
+
+	// Priority of lexer.
+	//
+	// If this is 0 it will be treated as a default of 1.
+	Priority float32
 }
 
 // Token output to formatter.
@@ -80,32 +85,30 @@ type Lexer interface {
 	Tokenise(options *TokeniseOptions, text string) (Iterator, error)
 }
 
+// Lexers is a slice of lexers sortable by name.
 type Lexers []Lexer
 
-// Pick attempts to pick the best Lexer for a piece of source code. May return nil.
-func (l Lexers) Pick(text string) Lexer {
-	if len(l) == 0 {
-		return nil
-	}
-	var picked Lexer
-	highest := float32(-1)
-	for _, lexer := range l {
-		if analyser, ok := lexer.(Analyser); ok {
-			score := analyser.AnalyseText(text)
-			if score > highest {
-				highest = score
-				picked = lexer
-				continue
-			}
-		}
-	}
-	return picked
-}
-
 func (l Lexers) Len() int           { return len(l) }
 func (l Lexers) Swap(i, j int)      { l[i], l[j] = l[j], l[i] }
 func (l Lexers) Less(i, j int) bool { return l[i].Config().Name < l[j].Config().Name }
 
+// PrioritisedLexers is a slice of lexers sortable by priority.
+type PrioritisedLexers []Lexer
+
+func (l PrioritisedLexers) Len() int      { return len(l) }
+func (l PrioritisedLexers) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
+func (l PrioritisedLexers) Less(i, j int) bool {
+	ip := l[i].Config().Priority
+	if ip == 0 {
+		ip = 1
+	}
+	jp := l[j].Config().Priority
+	if jp == 0 {
+		jp = 1
+	}
+	return ip > jp
+}
+
 // Analyser determines how appropriate this lexer is for the given text.
 type Analyser interface {
 	AnalyseText(text string) float32

lexers/api.go

@@ -43,37 +43,52 @@ func Get(name string) chroma.Lexer {
 
 // MatchMimeType attempts to find a lexer for the given MIME type.
 func MatchMimeType(mimeType string) chroma.Lexer {
+	matched := chroma.PrioritisedLexers{}
 	for _, l := range Registry.Lexers {
 		for _, lmt := range l.Config().MimeTypes {
 			if mimeType == lmt {
-				return l
+				matched = append(matched, l)
 			}
 		}
 	}
+	if len(matched) != 0 {
+		sort.Sort(matched)
+		return matched[0]
+	}
 	return nil
 }
 
 // Match returns the first lexer matching filename.
 func Match(filename string) chroma.Lexer {
 	filename = filepath.Base(filename)
+	matched := chroma.PrioritisedLexers{}
 	// First, try primary filename matches.
 	for _, lexer := range Registry.Lexers {
 		config := lexer.Config()
 		for _, glob := range config.Filenames {
 			if fnmatch.Match(glob, filename, 0) {
-				return lexer
+				matched = append(matched, lexer)
 			}
 		}
 	}
+	if len(matched) > 0 {
+		sort.Sort(matched)
+		return matched[0]
+	}
+	matched = nil
 	// Next, try filename aliases.
 	for _, lexer := range Registry.Lexers {
 		config := lexer.Config()
 		for _, glob := range config.AliasFilenames {
 			if fnmatch.Match(glob, filename, 0) {
-				return lexer
+				matched = append(matched, lexer)
 			}
 		}
 	}
+	if len(matched) > 0 {
+		sort.Sort(matched)
+		return matched[0]
+	}
 	return nil
 }
 

lexers/mason.go

@@ -11,6 +11,7 @@ var Mason = Register(MustNewLexer(
 		Aliases:   []string{"mason"},
 		Filenames: []string{"*.m", "*.mhtml", "*.mc", "*.mi", "autohandler", "dhandler"},
 		MimeTypes: []string{"application/x-mason"},
+		Priority:  0.1,
 	},
 	Rules{
 		"root": {

lexers/objectivec.go

@@ -0,0 +1,164 @@
+package lexers
+
+import (
+	. "github.com/alecthomas/chroma" // nolint
+)
+
+// Objective-C lexer.
+var ObjectiveC = Register(MustNewLexer(
+	&Config{
+		Name:      "Objective-C",
+		Aliases:   []string{"objective-c", "objectivec", "obj-c", "objc"},
+		Filenames: []string{"*.m", "*.h"},
+		MimeTypes: []string{"text/x-objective-c"},
+	},
+	Rules{
+		"statements": {
+			{`@"`, LiteralString, Push("string")},
+			{`@(YES|NO)`, LiteralNumber, nil},
+			{`@'(\\.|\\[0-7]{1,3}|\\x[a-fA-F0-9]{1,2}|[^\\\'\n])'`, LiteralStringChar, nil},
+			{`@(\d+\.\d*|\.\d+|\d+)[eE][+-]?\d+[lL]?`, LiteralNumberFloat, nil},
+			{`@(\d+\.\d*|\.\d+|\d+[fF])[fF]?`, LiteralNumberFloat, nil},
+			{`@0x[0-9a-fA-F]+[Ll]?`, LiteralNumberHex, nil},
+			{`@0[0-7]+[Ll]?`, LiteralNumberOct, nil},
+			{`@\d+[Ll]?`, LiteralNumberInteger, nil},
+			{`@\(`, Literal, Push("literal_number")},
+			{`@\[`, Literal, Push("literal_array")},
+			{`@\{`, Literal, Push("literal_dictionary")},
+			{Words(``, `\b`, `@selector`, `@private`, `@protected`, `@public`, `@encode`, `@synchronized`, `@try`, `@throw`, `@catch`, `@finally`, `@end`, `@property`, `@synthesize`, `__bridge`, `__bridge_transfer`, `__autoreleasing`, `__block`, `__weak`, `__strong`, `weak`, `strong`, `copy`, `retain`, `assign`, `unsafe_unretained`, `atomic`, `nonatomic`, `readonly`, `readwrite`, `setter`, `getter`, `typeof`, `in`, `out`, `inout`, `release`, `class`, `@dynamic`, `@optional`, `@required`, `@autoreleasepool`), Keyword, nil},
+			{Words(``, `\b`, `id`, `instancetype`, `Class`, `IMP`, `SEL`, `BOOL`, `IBOutlet`, `IBAction`, `unichar`), KeywordType, nil},
+			{`@(true|false|YES|NO)\n`, NameBuiltin, nil},
+			{`(YES|NO|nil|self|super)\b`, NameBuiltin, nil},
+			{`(Boolean|UInt8|SInt8|UInt16|SInt16|UInt32|SInt32)\b`, KeywordType, nil},
+			{`(TRUE|FALSE)\b`, NameBuiltin, nil},
+			{`(@interface|@implementation)(\s+)`, ByGroups(Keyword, Text), Push("#pop", "oc_classname")},
+			{`(@class|@protocol)(\s+)`, ByGroups(Keyword, Text), Push("#pop", "oc_forward_classname")},
+			{`@`, Punctuation, nil},
+			{`(L?)(")`, ByGroups(LiteralStringAffix, LiteralString), Push("string")},
+			{`(L?)(')(\\.|\\[0-7]{1,3}|\\x[a-fA-F0-9]{1,2}|[^\\\'\n])(')`, ByGroups(LiteralStringAffix, LiteralStringChar, LiteralStringChar, LiteralStringChar), nil},
+			{`(\d+\.\d*|\.\d+|\d+)[eE][+-]?\d+[LlUu]*`, LiteralNumberFloat, nil},
+			{`(\d+\.\d*|\.\d+|\d+[fF])[fF]?`, LiteralNumberFloat, nil},
+			{`0x[0-9a-fA-F]+[LlUu]*`, LiteralNumberHex, nil},
+			{`0[0-7]+[LlUu]*`, LiteralNumberOct, nil},
+			{`\d+[LlUu]*`, LiteralNumberInteger, nil},
+			{`\*/`, Error, nil},
+			{`[~!%^&*+=|?:<>/-]`, Operator, nil},
+			{`[()\[\],.]`, Punctuation, nil},
+			{Words(``, `\b`, `asm`, `auto`, `break`, `case`, `const`, `continue`, `default`, `do`, `else`, `enum`, `extern`, `for`, `goto`, `if`, `register`, `restricted`, `return`, `sizeof`, `static`, `struct`, `switch`, `typedef`, `union`, `volatile`, `while`), Keyword, nil},
+			{`(bool|int|long|float|short|double|char|unsigned|signed|void)\b`, KeywordType, nil},
+			{Words(``, `\b`, `inline`, `_inline`, `__inline`, `naked`, `restrict`, `thread`, `typename`), KeywordReserved, nil},
+			{`(__m(128i|128d|128|64))\b`, KeywordReserved, nil},
+			{Words(`__`, `\b`, `asm`, `int8`, `based`, `except`, `int16`, `stdcall`, `cdecl`, `fastcall`, `int32`, `declspec`, `finally`, `int64`, `try`, `leave`, `wchar_t`, `w64`, `unaligned`, `raise`, `noop`, `identifier`, `forceinline`, `assume`), KeywordReserved, nil},
+			{`(true|false|NULL)\b`, NameBuiltin, nil},
+			{`([a-zA-Z_]\w*)(\s*)(:)(?!:)`, ByGroups(NameLabel, Text, Punctuation), nil},
+			{`[a-zA-Z_]\w*`, Name, nil},
+		},
+		"oc_classname": {
+			{`([a-zA-Z$_][\w$]*)(\s*:\s*)([a-zA-Z$_][\w$]*)?(\s*)(\{)`, ByGroups(NameClass, Text, NameClass, Text, Punctuation), Push("#pop", "oc_ivars")},
+			{`([a-zA-Z$_][\w$]*)(\s*:\s*)([a-zA-Z$_][\w$]*)?`, ByGroups(NameClass, Text, NameClass), Pop(1)},
+			{`([a-zA-Z$_][\w$]*)(\s*)(\([a-zA-Z$_][\w$]*\))(\s*)(\{)`, ByGroups(NameClass, Text, NameLabel, Text, Punctuation), Push("#pop", "oc_ivars")},
+			{`([a-zA-Z$_][\w$]*)(\s*)(\([a-zA-Z$_][\w$]*\))`, ByGroups(NameClass, Text, NameLabel), Pop(1)},
+			{`([a-zA-Z$_][\w$]*)(\s*)(\{)`, ByGroups(NameClass, Text, Punctuation), Push("#pop", "oc_ivars")},
+			{`([a-zA-Z$_][\w$]*)`, NameClass, Pop(1)},
+		},
+		"oc_forward_classname": {
+			{`([a-zA-Z$_][\w$]*)(\s*,\s*)`, ByGroups(NameClass, Text), Push("oc_forward_classname")},
+			{`([a-zA-Z$_][\w$]*)(\s*;?)`, ByGroups(NameClass, Text), Pop(1)},
+		},
+		"oc_ivars": {
+			Include("whitespace"),
+			Include("statements"),
+			{`;`, Punctuation, nil},
+			{`\{`, Punctuation, Push()},
+			{`\}`, Punctuation, Pop(1)},
+		},
+		"root": {
+			{`^([-+])(\s*)(\(.*?\))?(\s*)([a-zA-Z$_][\w$]*:?)`, ByGroups(Punctuation, Text, UsingSelf("root"), Text, NameFunction), Push("method")},
+			Include("whitespace"),
+			{`((?:[\w*\s])+?(?:\s|[*]))([a-zA-Z_]\w*)(\s*\([^;]*?\))([^;{]*)(\{)`, ByGroups(UsingSelf("root"), NameFunction, UsingSelf("root"), UsingSelf("root"), Punctuation), Push("function")},
+			{`((?:[\w*\s])+?(?:\s|[*]))([a-zA-Z_]\w*)(\s*\([^;]*?\))([^;]*)(;)`, ByGroups(UsingSelf("root"), NameFunction, UsingSelf("root"), UsingSelf("root"), Punctuation), nil},
+			Default(Push("statement")),
+		},
+		"method": {
+			Include("whitespace"),
+			{`,`, Punctuation, nil},
+			{`\.\.\.`, Punctuation, nil},
+			{`(\(.*?\))(\s*)([a-zA-Z$_][\w$]*)`, ByGroups(UsingSelf("root"), Text, NameVariable), nil},
+			{`[a-zA-Z$_][\w$]*:`, NameFunction, nil},
+			{`;`, Punctuation, Pop(1)},
+			{`\{`, Punctuation, Push("function")},
+			Default(Pop(1)),
+		},
+		"literal_number": {
+			{`\(`, Punctuation, Push("literal_number_inner")},
+			{`\)`, Literal, Pop(1)},
+			Include("statement"),
+		},
+		"literal_number_inner": {
+			{`\(`, Punctuation, Push()},
+			{`\)`, Punctuation, Pop(1)},
+			Include("statement"),
+		},
+		"literal_array": {
+			{`\[`, Punctuation, Push("literal_array_inner")},
+			{`\]`, Literal, Pop(1)},
+			Include("statement"),
+		},
+		"literal_array_inner": {
+			{`\[`, Punctuation, Push()},
+			{`\]`, Punctuation, Pop(1)},
+			Include("statement"),
+		},
+		"literal_dictionary": {
+			{`\}`, Literal, Pop(1)},
+			Include("statement"),
+		},
+		"whitespace": {
+			{`^#if\s+0`, CommentPreproc, Push("if0")},
+			{`^#`, CommentPreproc, Push("macro")},
+			{`^(\s*(?:/[*].*?[*]/\s*)?)(#if\s+0)`, ByGroups(UsingSelf("root"), CommentPreproc), Push("if0")},
+			{`^(\s*(?:/[*].*?[*]/\s*)?)(#)`, ByGroups(UsingSelf("root"), CommentPreproc), Push("macro")},
+			{`\n`, Text, nil},
+			{`\s+`, Text, nil},
+			{`\\\n`, Text, nil},
+			{`//(\n|[\w\W]*?[^\\]\n)`, CommentSingle, nil},
+			{`/(\\\n)?[*][\w\W]*?[*](\\\n)?/`, CommentMultiline, nil},
+			{`/(\\\n)?[*][\w\W]*`, CommentMultiline, nil},
+		},
+		"statement": {
+			Include("whitespace"),
+			Include("statements"),
+			{`[{}]`, Punctuation, nil},
+			{`;`, Punctuation, Pop(1)},
+		},
+		"function": {
+			Include("whitespace"),
+			Include("statements"),
+			{`;`, Punctuation, nil},
+			{`\{`, Punctuation, Push()},
+			{`\}`, Punctuation, Pop(1)},
+		},
+		"string": {
+			{`"`, LiteralString, Pop(1)},
+			{`\\([\\abfnrtv"\']|x[a-fA-F0-9]{2,4}|u[a-fA-F0-9]{4}|U[a-fA-F0-9]{8}|[0-7]{1,3})`, LiteralStringEscape, nil},
+			{`[^\\"\n]+`, LiteralString, nil},
+			{`\\\n`, LiteralString, nil},
+			{`\\`, LiteralString, nil},
+		},
+		"macro": {
+			{`(include)(\s*(?:/[*].*?[*]/\s*)?)([^\n]+)`, ByGroups(CommentPreproc, Text, CommentPreprocFile), nil},
+			{`[^/\n]+`, CommentPreproc, nil},
+			{`/[*](.|\n)*?[*]/`, CommentMultiline, nil},
+			{`//.*?\n`, CommentSingle, Pop(1)},
+			{`/`, CommentPreproc, nil},
+			{`(?<=\\)\n`, CommentPreproc, nil},
+			{`\n`, CommentPreproc, Pop(1)},
+		},
+		"if0": {
+			{`^\s*#if.*?(?<!\\)\n`, CommentPreproc, Push()},
+			{`^\s*#el(?:se|if).*\n`, CommentPreproc, Pop(1)},
+			{`^\s*#endif.*?(?<!\\)\n`, CommentPreproc, Pop(1)},
+			{`.*?\n`, Comment, nil},
+		},
+	},
+))