Change syntax for top-level directives

%name changes to:

#name example;

%left and %right change to:

#prec (
    #left a b
    #right c d
);

22 files changed, 892 insertions, 385 deletions

diff --git a/README.md b/README.md
index b7f6206..92c270c 100644
--- a/README.md
+++ b/README.md
@@ -25,10 +25,12 @@ $ go install github.com/nihei9/vartan/cmd/vartan-go@latest
 vartan uses BNF-like DSL to define your grammar. As an example, let's write a grammar that represents a simple expression.
 
 ```
-%name expr
+#name expr;
 
-%left mul div
-%left add sub
+#prec (
+    #left mul div
+    #left add sub
+);
 
 expr
 	: expr add expr
@@ -234,7 +236,7 @@ exit status 1
 
 ### Grammar name
 
-A grammar name `%name <Identifier>` is an identifier that represents a grammar name. For now, this identifier is used as a file name generated like _<grammar-name>\_parser.go_.
+A grammar name `#name <Identifier>` is an identifier that represents a grammar name. For now, this identifier is used as a file name generated like _<grammar-name>\_parser.go_.
 
 ### Production rules
 
@@ -325,7 +327,7 @@ example 1:
 Consider a grammar that accepts comma-separated list of integers. You can avoid including brackets and commas in an AST by specifying only the necessary symbols int the `#ast` directive parameters. Also, you can flatten an AST using `...` operator. `...` operator expands child nodes of a specified symbol.
 
 ```
-%name example
+#name example;
 
 list
 	: '[' elems ']' #ast elems...
@@ -356,7 +358,7 @@ example 2:
 Consider a grammar that accepts ternary-if expression (`<condition> ? <value if true> : <value if false>`). As this grammar contains two `int` symbols, you need to add labels to each symbol to distinguish them. A label consists of `@` + an identifier.
 
 ```
-%name example
+#name example;
 
 if_expr
 	: id '?' int@true ':' int@false #ast id true false
@@ -405,7 +407,7 @@ An `#alias` directive aliases for a terminal symbol. You can use the alias in er
 example:
 
 ```
-%name example
+#name example;
 
 s
 	: id
@@ -424,7 +426,7 @@ When the parser shifts a terminal symbol having the `#push` directive, the curre
 example:
 
 ```
-%name example
+#name example;
 
 tag_pairs
 	: tag_pairs tag_pair
@@ -471,7 +473,7 @@ The parser doesn't shift a terminal symbol having a `#skip` directive. In other
 example:
 
 ```
-%name example
+#name example;
 
 s
 	: foo bar
@@ -497,7 +499,7 @@ foobar
 
 ### Operator precedence and associativity
 
-`%left` and `%right` allow you to define precedence and associativiry of symbols. `%left`/`%right` each assign the left/right associativity to symbols.
+`#left` and `#right` directives allow you to define precedence and associativiry of symbols. `#left`/`#right` each assign the left/right associativity to symbols.
 
 When the right-most terminal symbol of an alternative has precedence or associativity defined explicitly, the alternative inherits its precedence and associativity.
 
@@ -506,11 +508,13 @@ When the right-most terminal symbol of an alternative has precedence or associat
 The grammar for simple four arithmetic operations and assignment expression can be defined as follows:
 
 ```
-%name example
+#name example;
 
-%left mul div
-%left add sub
-%right assign
+#prec (
+    #left mul div
+    #left add sub
+    #right assign
+);
 
 expr
 	: expr add expr
@@ -541,11 +545,11 @@ assign
 	: '=';
 ```
 
-`%left` and `%right` can appear multiple times, and the first symbols applied to will have the highest precedence. That is, `mul` and `div` have the highest precedence, and `assign` has the lowest precedence.
+`#left` and `#right` can appear multiple times, and the first symbols applied to will have the highest precedence. That is, `mul` and `div` have the highest precedence, and `assign` has the lowest precedence.
 
 ⚠️ In many Yacc-like tools, the last symbols defined have the highest precedence. Not that in vartan, it is the opposite.
 
-When you compile the above grammar, some conflicts occur. However, vartan can resolve the conflicts following `%left`, `%right`, and `#prec`.
+When you compile the above grammar, some conflicts occur. However, vartan can resolve the conflicts following `#left`, `#right`, and `#prec`.
 
 ```
 $ echo -n 'foo = bar = x * -1 / -2' | vartan parse example.json
@@ -572,7 +576,7 @@ expr
 Incidentally, using no directives, you can define the above example as the following grammar:
 
 ```
-%name example
+#name example;
 
 expr
 	: id assign expr
@@ -651,7 +655,7 @@ When a syntax error occurs, the parser pops states from a state stack. If a stat
 Consider grammar of simple assignment statements.
 
 ```
-%name example
+#name example;
 
 statements
 	: statements statement #ast statements... statement
diff --git a/driver/conflict_test.go b/driver/conflict_test.go
index 7672c00..042d932 100644
--- a/driver/conflict_test.go
+++ b/driver/conflict_test.go
@@ -18,7 +18,7 @@ func TestParserWithConflicts(t *testing.T) {
 		{
 			caption: "when a shift/reduce conflict occurred, we prioritize the shift action",
 			specSrc: `
-%name test
+#name test;
 
 expr
     : expr assign expr
@@ -48,7 +48,7 @@ assign: '=';
 		{
 			caption: "when a reduce/reduce conflict occurred, we prioritize the production defined earlier in the grammar",
 			specSrc: `
-%name test
+#name test;
 
 s
     : a
@@ -73,10 +73,12 @@ id: "[A-Za-z0-9_]+";
 		{
 			caption: "left associativities defined earlier in the grammar have higher precedence",
 			specSrc: `
-%name test
+#name test;
 
-%left mul
-%left add
+#prec (
+    #left mul
+    #left add
+);
 
 expr
     : expr add expr
@@ -120,9 +122,11 @@ mul: '*';
 		{
 			caption: "left associativities defined in the same line have the same precedence",
 			specSrc: `
-%name test
+#name test;
 
-%left add sub
+#prec (
+    #left add sub
+);
 
 expr
     : expr add expr
@@ -166,10 +170,12 @@ sub: '-';
 		{
 			caption: "right associativities defined earlier in the grammar have higher precedence",
 			specSrc: `
-%name test
+#name test;
 
-%right r1
-%right r2
+#prec (
+    #right r1
+    #right r2
+);
 
 expr
     : expr r2 expr
@@ -218,9 +224,11 @@ id
 		{
 			caption: "right associativities defined in the same line have the same precedence",
 			specSrc: `
-%name test
+#name test;
 
-%right r1 r2
+#prec (
+    #right r1 r2
+);
 
 expr
     : expr r2 expr
@@ -269,11 +277,13 @@ id
 		{
 			caption: "left and right associativities can be mixed",
 			specSrc: `
-%name test
+#name test;
 
-%left mul div
-%left add sub
-%right assign
+#prec (
+    #left mul div
+    #left add sub
+    #right assign
+);
 
 expr
     : expr add expr
diff --git a/driver/lac_test.go b/driver/lac_test.go
index c127c0b..54001d5 100644
--- a/driver/lac_test.go
+++ b/driver/lac_test.go
@@ -10,7 +10,7 @@ import (
 
 func TestParserWithLAC(t *testing.T) {
 	specSrc := `
-%name test
+#name test;
 
 S
     : C C
diff --git a/driver/parser_test.go b/driver/parser_test.go
index c717205..c37d268 100644
--- a/driver/parser_test.go
+++ b/driver/parser_test.go
@@ -43,7 +43,7 @@ func TestParser_Parse(t *testing.T) {
 	}{
 		{
 			specSrc: `
-%name test
+#name test;
 
 expr
     : expr "\+" term
@@ -117,7 +117,7 @@ id: "[A-Za-z_][0-9A-Za-z_]*";
 		// The driver can reduce productions that have the empty alternative and can generate a CST (and AST) node.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -140,7 +140,7 @@ bar_text: "bar";
 		// The driver can reduce productions that have the empty alternative and can generate a CST (and AST) node.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -165,10 +165,12 @@ bar_text: "bar";
 		// A production can have multiple alternative productions.
 		{
 			specSrc: `
-%name test
+#name test;
 
-%left mul div
-%left add sub
+#prec (
+    #left mul div
+    #left add sub
+);
 
 expr
     : expr add expr
@@ -224,7 +226,7 @@ div
 		// A lexical production can have multiple production directives.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : push_a push_b pop pop
@@ -247,7 +249,7 @@ pop #mode a b #pop
 		},
 		{
 			specSrc: `
-%name test
+#name test;
 
 mode_tran_seq
     : mode_tran_seq mode_tran
@@ -275,7 +277,7 @@ whitespace #mode default m1 m2 #skip
 		},
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -291,7 +293,7 @@ bar #mode default
 		// When #push and #pop are applied to the same symbol, #pop will run first, then #push.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar baz
@@ -316,7 +318,7 @@ baz #mode m2
 		// they are executed.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar baz
@@ -339,7 +341,7 @@ baz #mode m2
 		// The parser can skips specified tokens.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -357,7 +359,7 @@ white_space #skip
 		// A grammar can contain fragments.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : tagline
@@ -370,7 +372,7 @@ fragment words: "[A-Za-z\u{0020}]+";
 		// A grammar can contain ast actions.
 		{
 			specSrc: `
-%name test
+#name test;
 
 list
     : "\[" elems "]" #ast elems...
@@ -410,7 +412,7 @@ id
 		// The '...' operator can expand child nodes.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : a #ast a...
@@ -433,7 +435,7 @@ foo
 		// The '...' operator also can applied to an element having no children.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : a ';' #ast a...
@@ -449,9 +451,11 @@ a
 		// A label can be a parameter of #ast directive.
 		{
 			specSrc: `
-%name test
+#name test;
 
-%left add sub
+#prec (
+    #left add sub
+);
 
 expr
     : expr@lhs add expr@rhs #ast add lhs rhs
@@ -482,7 +486,7 @@ num: "0|[1-9][0-9]*";
 		// An AST can contain a symbol name, even if the symbol has a label. That is, unused labels are allowed.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo@x ';' #ast foo
@@ -499,9 +503,11 @@ foo
 		// A production has the same precedence and associativity as the right-most terminal symbol.
 		{
 			specSrc: `
-%name test
+#name test;
 
-%left add
+#prec (
+    #left add
+);
 
 expr
     : expr add expr // This alternative has the same precedence and associativiry as 'add'.
@@ -544,10 +550,12 @@ add
 		// The 'prec' directive can set precedence of a production.
 		{
 			specSrc: `
-%name test
+#name test;
 
-%left mul div
-%left add sub
+#prec (
+    #left mul div
+    #left add sub
+);
 
 expr
     : expr add expr
@@ -603,7 +611,7 @@ div
 		// The grammar can contain the 'error' symbol.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : id id id ';'
@@ -620,7 +628,7 @@ id
 		// The 'error' symbol can appear in an #ast directive.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo ';'
@@ -639,7 +647,7 @@ foo
 		// The 'error' symbol can have a label, and an #ast can reference it.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo ';'
@@ -658,7 +666,7 @@ foo
 		// The grammar can contain the 'recover' directive.
 		{
 			specSrc: `
-%name test
+#name test;
 
 seq
     : seq elem
@@ -679,7 +687,7 @@ id
 		// The same label can be used between different alternatives.
 		{
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo@x bar
diff --git a/driver/semantic_action_test.go b/driver/semantic_action_test.go
index f9708b7..ad58780 100644
--- a/driver/semantic_action_test.go
+++ b/driver/semantic_action_test.go
@@ -47,7 +47,7 @@ func (a *testSemAct) MissError(cause VToken) {
 
 func TestParserWithSemanticAction(t *testing.T) {
 	specSrcWithErrorProd := `
-%name test
+#name test;
 
 seq
     : seq elem semicolon
@@ -70,7 +70,7 @@ char
 `
 
 	specSrcWithoutErrorProd := `
-%name test
+#name test;
 
 seq
     : seq elem semicolon
diff --git a/driver/syntax_error_test.go b/driver/syntax_error_test.go
index 329ccef..93cf637 100644
--- a/driver/syntax_error_test.go
+++ b/driver/syntax_error_test.go
@@ -19,7 +19,7 @@ func TestParserWithSyntaxErrors(t *testing.T) {
 		{
 			caption: "the parser can report a syntax error",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -33,7 +33,7 @@ foo: 'foo';
 		{
 			caption: "when the parser reduced a production having the reduce directive, the parser will recover from an error state",
 			specSrc: `
-%name test
+#name test;
 
 seq
     : seq elem ';'
@@ -59,7 +59,7 @@ c
 		{
 			caption: "After the parser shifts the error symbol, symbols are ignored until a symbol the parser can perform shift appears",
 			specSrc: `
-%name test
+#name test;
 
 seq
     : seq elem ';'
@@ -87,7 +87,7 @@ c
 		{
 			caption: "when the parser performs shift three times, the parser recovers from the error state",
 			specSrc: `
-%name test
+#name test;
 
 seq
     : seq elem ';'
diff --git a/grammar/first_test.go b/grammar/first_test.go
index 578825e..134f4bd 100644
--- a/grammar/first_test.go
+++ b/grammar/first_test.go
@@ -24,7 +24,7 @@ func TestGenFirst(t *testing.T) {
 		{
 			caption: "productions contain only non-empty productions",
 			src: `
-%name test
+#name test;
 
 expr
     : expr add term
@@ -63,7 +63,7 @@ id: "[A-Za-z_][0-9A-Za-z_]*";
 		{
 			caption: "productions contain the empty start production",
 			src: `
-%name test
+#name test;
 
 s
     :
@@ -77,7 +77,7 @@ s
 		{
 			caption: "productions contain an empty production",
 			src: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -96,7 +96,7 @@ bar: "bar";
 		{
 			caption: "a start production contains a non-empty alternative and empty alternative",
 			src: `
-%name test
+#name test;
 
 s
     : foo
@@ -113,7 +113,7 @@ foo: "foo";
 		{
 			caption: "a production contains non-empty alternative and empty alternative",
 			src: `
-%name test
+#name test;
 
 s
     : foo
diff --git a/grammar/follow_test.go b/grammar/follow_test.go
index af3f064..719582f 100644
--- a/grammar/follow_test.go
+++ b/grammar/follow_test.go
@@ -22,7 +22,7 @@ func TestFollowSet(t *testing.T) {
 		{
 			caption: "productions contain only non-empty productions",
 			src: `
-%name test
+#name test;
 
 expr
     : expr add term
@@ -52,7 +52,7 @@ id: "[A-Za-z_][0-9A-Za-z_]*";
 		{
 			caption: "productions contain an empty start production",
 			src: `
-%name test
+#name test;
 
 s
     :
@@ -66,7 +66,7 @@ s
 		{
 			caption: "productions contain an empty production",
 			src: `
-%name test
+#name test;
 
 s
     : foo
@@ -84,7 +84,7 @@ foo
 		{
 			caption: "a start production contains a non-empty alternative and empty alternative",
 			src: `
-%name test
+#name test;
 
 s
     : foo
@@ -100,7 +100,7 @@ foo: "foo";
 		{
 			caption: "a production contains non-empty alternative and empty alternative",
 			src: `
-%name test
+#name test;
 
 s
     : foo
diff --git a/grammar/grammar.go b/grammar/grammar.go
index d46d70e..da0460b 100644
--- a/grammar/grammar.go
+++ b/grammar/grammar.go
@@ -109,30 +109,30 @@ func (b *GrammarBuilder) Build() (*Grammar, error) {
 	var specName string
 	{
 		errOccurred := false
-		for _, md := range b.AST.MetaData {
-			if md.Name != "name" {
+		for _, dir := range b.AST.Directives {
+			if dir.Name != "name" {
 				continue
 			}
 
-			if len(md.Parameters) != 1 || md.Parameters[0].ID == "" {
+			if len(dir.Parameters) != 1 || dir.Parameters[0].ID == "" {
 				b.errs = append(b.errs, &verr.SpecError{
-					Cause:  semErrMDInvalidParam,
+					Cause:  semErrDirInvalidParam,
 					Detail: "'name' takes just one ID parameter",
-					Row:    md.Pos.Row,
-					Col:    md.Pos.Col,
+					Row:    dir.Pos.Row,
+					Col:    dir.Pos.Col,
 				})
 
 				errOccurred = true
 				break
 			}
 
-			specName = md.Parameters[0].ID
+			specName = dir.Parameters[0].ID
 			break
 		}
 
 		if specName == "" && !errOccurred {
 			b.errs = append(b.errs, &verr.SpecError{
-				Cause: semErrMDMissingName,
+				Cause: semErrNoGrammarName,
 			})
 		}
 	}
@@ -986,40 +986,63 @@ func (b *GrammarBuilder) genPrecAndAssoc(symTab *symbolTable, prods *productionS
 	termPrec := map[symbolNum]int{}
 	termAssoc := map[symbolNum]assocType{}
 	{
+		var precGroup []*spec.DirectiveNode
+		for _, dir := range b.AST.Directives {
+			if dir.Name == "prec" {
+				if dir.Parameters == nil || len(dir.Parameters) != 1 || dir.Parameters[0].Group == nil {
+					b.errs = append(b.errs, &verr.SpecError{
+						Cause:  semErrDirInvalidParam,
+						Detail: "'prec' needs just one directive group",
+						Row:    dir.Pos.Row,
+						Col:    dir.Pos.Col,
+					})
+					continue
+				}
+				precGroup = dir.Parameters[0].Group
+				continue
+			}
+
+			if dir.Name != "name" && dir.Name != "prec" {
+				b.errs = append(b.errs, &verr.SpecError{
+					Cause: semErrDirInvalidName,
+					Row:   dir.Pos.Row,
+					Col:   dir.Pos.Col,
+				})
+				continue
+			}
+		}
+
 		precN := precMin
-		for _, md := range b.AST.MetaData {
+		for _, dir := range precGroup {
 			var assocTy assocType
-			switch md.Name {
+			switch dir.Name {
 			case "left":
 				assocTy = assocTypeLeft
 			case "right":
 				assocTy = assocTypeRight
-			case "name":
-				// Since `name` is used for a purpose other than priority, we will ignore it here.
-				continue
 			default:
 				b.errs = append(b.errs, &verr.SpecError{
-					Cause: semErrMDInvalidName,
-					Row:   md.Pos.Row,
-					Col:   md.Pos.Col,
+					Cause: semErrDirInvalidName,
+					Row:   dir.Pos.Row,
+					Col:   dir.Pos.Col,
 				})
 				return nil, nil
 			}
 
-			if len(md.Parameters) == 0 {
+			if len(dir.Parameters) == 0 {
 				b.errs = append(b.errs, &verr.SpecError{
-					Cause:  semErrMDInvalidParam,
+					Cause:  semErrDirInvalidParam,
 					Detail: "associativity needs at least one symbol",
-					Row:    md.Pos.Row,
-					Col:    md.Pos.Col,
+					Row:    dir.Pos.Row,
+					Col:    dir.Pos.Col,
 				})
 				return nil, nil
 			}
 		ASSOC_PARAM_LOOP:
-			for _, p := range md.Parameters {
+			for _, p := range dir.Parameters {
 				if p.ID == "" {
 					b.errs = append(b.errs, &verr.SpecError{
-						Cause:  semErrMDInvalidParam,
+						Cause:  semErrDirInvalidParam,
 						Detail: "a parameter must be an ID",
 						Row:    p.Pos.Row,
 						Col:    p.Pos.Col,
@@ -1030,7 +1053,7 @@ func (b *GrammarBuilder) genPrecAndAssoc(symTab *symbolTable, prods *productionS
 				sym, ok := symTab.toSymbol(p.ID)
 				if !ok {
 					b.errs = append(b.errs, &verr.SpecError{
-						Cause:  semErrMDInvalidParam,
+						Cause:  semErrDirInvalidParam,
 						Detail: fmt.Sprintf("'%v' is undefined", p.ID),
 						Row:    p.Pos.Row,
 						Col:    p.Pos.Col,
@@ -1039,7 +1062,7 @@ func (b *GrammarBuilder) genPrecAndAssoc(symTab *symbolTable, prods *productionS
 				}
 				if !sym.isTerminal() {
 					b.errs = append(b.errs, &verr.SpecError{
-						Cause:  semErrMDInvalidParam,
+						Cause:  semErrDirInvalidParam,
 						Detail: fmt.Sprintf("associativity can take only terminal symbol ('%v' is a non-terminal)", p.ID),
 						Row:    p.Pos.Row,
 						Col:    p.Pos.Col,
diff --git a/grammar/grammar_test.go b/grammar/grammar_test.go
index 46458b0..07d8b58 100644
--- a/grammar/grammar_test.go
+++ b/grammar/grammar_test.go
@@ -17,9 +17,10 @@ func TestGrammarBuilderOK(t *testing.T) {
 
 	nameTests := []*okTest{
 		{
-			caption: "the `%name` can be the same identifier as a non-terminal symbol",
+			caption: "the `#name` can be the same identifier as a non-terminal symbol",
 			specSrc: `
-%name s
+#name s;
+
 s
     : foo
     ;
@@ -35,9 +36,10 @@ foo
 			},
 		},
 		{
-			caption: "the `%name` can be the same identifier as a terminal symbol",
+			caption: "the `#name` can be the same identifier as a terminal symbol",
 			specSrc: `
-%name foo
+#name foo;
+
 s
     : foo
     ;
@@ -53,9 +55,10 @@ foo
 			},
 		},
 		{
-			caption: "the `%name` can be the same identifier as the error symbol",
+			caption: "the `#name` can be the same identifier as the error symbol",
 			specSrc: `
-%name error
+#name error;
+
 s
     : foo
     | error
@@ -72,9 +75,10 @@ foo
 			},
 		},
 		{
-			caption: "the `%name` can be the same identifier as a fragment",
+			caption: "the `#name` can be the same identifier as a fragment",
 			specSrc: `
-%name f
+#name f;
+
 s
     : foo
     ;
@@ -97,7 +101,8 @@ fragment f
 		{
 			caption: "a `#mode` can be the same identifier as a non-terminal symbol",
 			specSrc: `
-%name test
+#name test;
+
 s
     : foo bar
     ;
@@ -121,7 +126,8 @@ bar #mode s
 		{
 			caption: "a `#mode` can be the same identifier as a terminal symbol",
 			specSrc: `
-%name test
+#name test;
+
 s
     : foo bar
     ;
@@ -145,7 +151,8 @@ bar #mode bar
 		{
 			caption: "a `#mode` can be the same identifier as the error symbol",
 			specSrc: `
-%name test
+#name test;
+
 s
     : foo bar
     | error
@@ -170,7 +177,8 @@ bar #mode error
 		{
 			caption: "a `#mode` can be the same identifier as a fragment",
 			specSrc: `
-%name test
+#name test;
+
 s
     : foo bar
     ;
@@ -194,11 +202,28 @@ fragment f
 			},
 		},
 		{
+			caption: "a `#prec` allows the empty directive group",
+			specSrc: `
+#name test;
+
+#prec ();
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+		},
+		{
 			caption: "a production has the same precedence and associativity as the right-most terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
-%left foo
+#prec (
+    #left foo
+);
 
 s
     : foo bar // This alternative has the same precedence and associativity as the right-most terminal symbol 'bar', not 'foo'.
@@ -236,10 +261,12 @@ bar
 		{
 			caption: "a production has the same precedence and associativity as the right-most terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
-%left foo
-%right bar
+#prec (
+    #left foo
+    #right bar
+);
 
 s
     : foo bar // This alternative has the same precedence and associativity as the right-most terminal symbol 'bar'.
@@ -275,11 +302,13 @@ bar
 			},
 		},
 		{
-			caption: "the `#prec` directive changes only precedence, not associativity",
+			caption: "the `#prec` directive applied to an alternative changes only precedence, not associativity",
 			specSrc: `
-%name test
+#name test;
 
-%left foo
+#prec (
+    #left foo
+);
 
 s
     : foo bar #prec foo
@@ -315,12 +344,14 @@ bar
 			},
 		},
 		{
-			caption: "the `#prec` directive changes only precedence, not associativity",
+			caption: "the `#prec` directive applied to an alternative changes only precedence, not associativity",
 			specSrc: `
-%name test
+#name test;
 
-%left foo
-%right bar
+#prec (
+    #left foo
+    #right bar
+);
 
 s
     : foo bar #prec foo
@@ -385,7 +416,9 @@ bar
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
-			test.validate(t, g)
+			if test.validate != nil {
+				test.validate(t, g)
+			}
 		})
 	}
 }
@@ -401,7 +434,7 @@ func TestGrammarBuilderSpecError(t *testing.T) {
 		{
 			caption: "a production `b` is unused",
 			specSrc: `
-%name test
+#name test;
 
 a
     : foo
@@ -418,7 +451,7 @@ foo
 		{
 			caption: "a terminal symbol `bar` is unused",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -434,7 +467,7 @@ bar
 		{
 			caption: "a production `b` and terminal symbol `bar` is unused",
 			specSrc: `
-%name test
+#name test;
 
 a
     : foo
@@ -456,7 +489,7 @@ bar
 		{
 			caption: "a production cannot have production directives",
 			specSrc: `
-%name test
+#name test;
 
 s #prec foo
     : foo
@@ -470,7 +503,7 @@ foo
 		{
 			caption: "a lexical production cannot have alternative directives",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -484,7 +517,7 @@ foo
 		{
 			caption: "a production directive must not be duplicated",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -498,7 +531,7 @@ foo #skip #skip
 		{
 			caption: "an alternative directive must not be duplicated",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar #ast foo bar #ast foo bar
@@ -514,7 +547,7 @@ bar
 		{
 			caption: "a production must not have a duplicate alternative (non-empty alternatives)",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -529,7 +562,7 @@ foo
 		{
 			caption: "a production must not have a duplicate alternative (non-empty and split alternatives)",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -552,7 +585,7 @@ bar
 		{
 			caption: "a production must not have a duplicate alternative (empty alternatives)",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -571,7 +604,7 @@ foo
 		{
 			caption: "a production must not have a duplicate alternative (empty and split alternatives)",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -593,7 +626,7 @@ foo
 		{
 			caption: "a terminal symbol and a non-terminal symbol (start symbol) are duplicates",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -609,7 +642,7 @@ s
 		{
 			caption: "a terminal symbol and a non-terminal symbol (not start symbol) are duplicates",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -629,11 +662,11 @@ a
 			errs: []*SemanticError{semErrDuplicateName},
 		},
 		{
-			caption: "an invalid associativity type",
+			caption: "an invalid top-level directive",
 			specSrc: `
-%name test
+#name test;
 
-%foo
+#foo;
 
 s
     : a
@@ -642,12 +675,12 @@ s
 a
     : 'a';
 `,
-			errs: []*SemanticError{semErrMDInvalidName},
+			errs: []*SemanticError{semErrDirInvalidName},
 		},
 		{
 			caption: "a label must be unique in an alternative",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo@x bar@x
@@ -663,7 +696,7 @@ bar
 		{
 			caption: "a label cannot be the same name as terminal symbols",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar@foo
@@ -679,7 +712,7 @@ bar
 		{
 			caption: "a label cannot be the same name as non-terminal symbols",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo@a
@@ -700,10 +733,85 @@ bar
 		},
 	}
 
-	nameTests := []*specErrTest{
+	nameDirTests := []*specErrTest{
+		{
+			caption: "the `#name` directive is required",
+			specSrc: `
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrNoGrammarName},
+		},
+		{
+			caption: "the `#name` directive needs an ID parameter",
+			specSrc: `
+#name;
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
+			caption: "the `#name` directive cannot take a pattern parameter",
+			specSrc: `
+#name "test";
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
+			caption: "the `#name` directive cannot take a string parameter",
+			specSrc: `
+#name 'test';
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
+			caption: "the `#name` directive takes just one parameter",
+			specSrc: `
+#name test1 test2;
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+	}
+
+	precDirTests := []*specErrTest{
 		{
-			caption: "the `%name` is required",
+			caption: "the `#prec` directive needs a directive group parameter",
 			specSrc: `
+#name test;
+
+#prec;
+
 s
     : foo
     ;
@@ -711,12 +819,14 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDMissingName},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%name` needs an ID parameter",
+			caption: "the `#prec` directive cannot take an ID parameter",
 			specSrc: `
-%name
+#name test;
+
+#prec foo;
 
 s
     : foo
@@ -725,12 +835,14 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%name` takes just one parameter",
+			caption: "the `#prec` directive cannot take a pattern parameter",
 			specSrc: `
-%name test1 test2
+#name test;
+
+#prec "foo";
 
 s
     : foo
@@ -739,17 +851,51 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
+			caption: "the `#prec` directive cannot take a string parameter",
+			specSrc: `
+#name test;
+
+#prec 'foo';
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
+			caption: "the `#prec` directive takes just one directive group parameter",
+			specSrc: `
+#name test;
+
+#prec () ();
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 	}
 
-	leftTests := []*specErrTest{
+	leftDirTests := []*specErrTest{
 		{
-			caption: "the `%left` needs ID parameters",
+			caption: "the `#left` directive needs ID parameters",
 			specSrc: `
-%name test
+#name test;
 
-%left
+#prec (
+    #left
+);
 
 s
     : foo
@@ -758,14 +904,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%left` cannot take an undefined symbol",
+			caption: "the `#left` directive cannot take an undefined symbol",
 			specSrc: `
-%name test
+#name test;
 
-%left x
+#prec (
+    #left x
+);
 
 s
     : foo
@@ -774,14 +922,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%left` cannot take a non-terminal symbol",
+			caption: "the `#left` directive cannot take a non-terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
-%left s
+#prec (
+    #left s
+);
 
 s
     : foo
@@ -790,14 +940,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%left` cannot take a pattern parameter",
+			caption: "the `#left` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
-%left "foo"
+#prec (
+    #left "foo"
+);
 
 s
     : foo
@@ -806,14 +958,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%left` cannot take a string parameter",
+			caption: "the `#left` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
-%left 'foo'
+#prec (
+    #left 'foo'
+);
 
 s
     : foo
@@ -822,14 +976,34 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%left` cannot be specified multiple times for a symbol",
+			caption: "the `#left` directive cannot take a directive parameter",
 			specSrc: `
-%name test
+#name test;
 
-%left foo foo
+#prec (
+    #left ()
+);
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
+			caption: "the `#left` dirctive cannot be specified multiple times for a symbol",
+			specSrc: `
+#name test;
+
+#prec (
+    #left foo foo
+);
 
 s
     : foo
@@ -843,10 +1017,12 @@ foo
 		{
 			caption: "a symbol cannot have different precedence",
 			specSrc: `
-%name test
+#name test;
 
-%left foo
-%left foo
+#prec (
+    #left foo
+    #left foo
+);
 
 s
     : foo
@@ -860,10 +1036,12 @@ foo
 		{
 			caption: "a symbol cannot have different associativity",
 			specSrc: `
-%name test
+#name test;
 
-%right foo
-%left foo
+#prec (
+    #right foo
+    #left foo
+);
 
 s
     : foo
@@ -876,13 +1054,15 @@ foo
 		},
 	}
 
-	rightTests := []*specErrTest{
+	rightDirTests := []*specErrTest{
 		{
-			caption: "the `%right` needs ID parameters",
+			caption: "the `#right` directive needs ID parameters",
 			specSrc: `
-%name test
+#name test;
 
-%right
+#prec (
+    #right
+);
 
 s
     : foo
@@ -891,14 +1071,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%right` cannot take an undefined symbol",
+			caption: "the `#right` directive cannot take an undefined symbol",
 			specSrc: `
-%name test
+#name test;
 
-%right x
+#prec (
+    #right x
+);
 
 s
     : foo
@@ -907,14 +1089,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%right` cannot take a non-terminal symbol",
+			caption: "the `#right` directive cannot take a non-terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
-%right s
+#prec (
+    #right s
+);
 
 s
     : foo
@@ -923,14 +1107,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%right` cannot take a pattern parameter",
+			caption: "the `#right` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
-%right "foo"
+#prec (
+    #right "foo"
+);
 
 s
     : foo
@@ -939,14 +1125,16 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%right` cannot take a string parameter",
+			caption: "the `#right` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
-%right 'foo'
+#prec (
+    #right 'foo'
+);
 
 s
     : foo
@@ -955,14 +1143,34 @@ s
 foo
     : 'foo';
 `,
-			errs: []*SemanticError{semErrMDInvalidParam},
+			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
-			caption: "the `%right` cannot be specified multiple times for a symbol",
+			caption: "the `#right` directive cannot take a directive group parameter",
 			specSrc: `
-%name test
+#name test;
 
-%right foo foo
+#prec (
+    #right ()
+);
+
+s
+    : foo
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
+			caption: "the `#right` directive cannot be specified multiple times for a symbol",
+			specSrc: `
+#name test;
+
+#prec (
+    #right foo foo
+);
 
 s
     : foo
@@ -976,10 +1184,12 @@ foo
 		{
 			caption: "a symbol cannot have different precedence",
 			specSrc: `
-%name test
+#name test;
 
-%right foo
-%right foo
+#prec (
+    #right foo
+    #right foo
+);
 
 s
     : foo
@@ -993,10 +1203,12 @@ foo
 		{
 			caption: "a symbol cannot have different associativity",
 			specSrc: `
-%name test
+#name test;
 
-%left foo
-%right foo
+#prec (
+    #left foo
+    #right foo
+);
 
 s
     : foo
@@ -1013,7 +1225,7 @@ foo
 		{
 			caption: "cannot use the error symbol as a non-terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
 s
     : error
@@ -1032,7 +1244,7 @@ foo: 'foo';
 		{
 			caption: "cannot use the error symbol as a terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
 s
     : error
@@ -1045,7 +1257,7 @@ error: 'error';
 		{
 			caption: "cannot use the error symbol as a terminal symbol, even if given the skip directive",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -1064,7 +1276,7 @@ error #skip
 		{
 			caption: "the `#ast` directive needs ID or label prameters",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #ast
@@ -1078,7 +1290,7 @@ foo
 		{
 			caption: "the `#ast` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #ast "foo"
@@ -1092,7 +1304,7 @@ foo
 		{
 			caption: "the `#ast` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #ast 'foo'
@@ -1104,9 +1316,23 @@ foo
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
+			caption: "the `#ast` directive cannot take a directive group parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo #ast ()
+    ;
+
+foo
+    : "foo";
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
 			caption: "a parameter of the `#ast` directive must be either a symbol or a label in an alternative",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar #ast foo x
@@ -1122,7 +1348,7 @@ bar
 		{
 			caption: "a symbol in a different alternative cannot be a parameter of the `#ast` directive",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #ast bar
@@ -1139,7 +1365,7 @@ bar
 		{
 			caption: "a label in a different alternative cannot be a parameter of the `#ast` directive",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #ast b
@@ -1156,7 +1382,7 @@ bar
 		{
 			caption: "a symbol can appear in the `#ast` directive only once",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #ast foo foo
@@ -1170,7 +1396,7 @@ foo
 		{
 			caption: "a label can appear in the `#ast` directive only once",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo@x #ast x x
@@ -1184,7 +1410,7 @@ foo
 		{
 			caption: "a symbol can appear in the `#ast` directive only once, even if the symbol has a label",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo@x #ast foo x
@@ -1198,7 +1424,7 @@ foo
 		{
 			caption: "symbol `foo` is ambiguous because it appears in an alternative twice",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo foo #ast foo
@@ -1212,7 +1438,7 @@ foo
 		{
 			caption: "symbol `foo` is ambiguous because it appears in an alternative twice, even if one of them has a label",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo@x foo #ast foo
@@ -1226,7 +1452,7 @@ foo
 		{
 			caption: "the expansion operator cannot be applied to a terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #ast foo...
@@ -1240,7 +1466,7 @@ foo
 		{
 			caption: "the expansion operator cannot be applied to a pattern",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo "bar"@b #ast foo b...
@@ -1254,7 +1480,7 @@ foo
 		{
 			caption: "the expansion operator cannot be applied to a string",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo 'bar'@b #ast foo b...
@@ -1267,11 +1493,11 @@ foo
 		},
 	}
 
-	precDirTests := []*specErrTest{
+	altPrecDirTests := []*specErrTest{
 		{
 			caption: "the `#prec` directive needs an ID parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #prec
@@ -1285,7 +1511,7 @@ foo
 		{
 			caption: "the `#prec` directive cannot take an undefined symbol",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #prec x
@@ -1299,7 +1525,7 @@ foo
 		{
 			caption: "the `#prec` directive cannot take a non-terminal symbol",
 			specSrc: `
-%name test
+#name test;
 
 s
     : a #prec b
@@ -1322,7 +1548,7 @@ bar
 		{
 			caption: "the `#prec` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #prec "foo"
@@ -1336,7 +1562,7 @@ foo
 		{
 			caption: "the `#prec` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo #prec 'foo'
@@ -1348,9 +1574,23 @@ foo
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
+			caption: "the `#prec` directive cannot take a directive parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo #prec ()
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
 			caption: "a symbol the `#prec` directive takes must be given precedence explicitly",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar #prec foo
@@ -1369,9 +1609,7 @@ bar
 		{
 			caption: "the `#recover` directive cannot take an ID parameter",
 			specSrc: `
-%name test
-
-%name test
+#name test;
 
 s
     : foo #recover foo
@@ -1385,9 +1623,7 @@ foo
 		{
 			caption: "the `#recover` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
-
-%name test
+#name test;
 
 s
     : foo #recover "foo"
@@ -1401,9 +1637,7 @@ foo
 		{
 			caption: "the `#recover` directive cannot take a string parameter",
 			specSrc: `
-%name test
-
-%name test
+#name test;
 
 s
     : foo #recover 'foo'
@@ -1414,13 +1648,27 @@ foo
 `,
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
+		{
+			caption: "the `#recover` directive cannot take a directive group parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo #recover ()
+    ;
+
+foo
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
 	}
 
 	fragmentTests := []*specErrTest{
 		{
 			caption: "a production cannot contain a fragment",
 			specSrc: `
-%name test
+#name test;
 
 s
     : f
@@ -1434,7 +1682,7 @@ fragment f
 		{
 			caption: "fragments cannot be duplicated",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -1455,7 +1703,7 @@ fragment f
 		{
 			caption: "the `#alias` directive needs a string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -1469,7 +1717,7 @@ foo #alias
 		{
 			caption: "the `#alias` directive takes just one string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -1483,7 +1731,7 @@ foo #alias 'Foo' 'FOO'
 		{
 			caption: "the `#alias` directive cannot take an ID parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -1497,7 +1745,7 @@ foo #alias Foo
 		{
 			caption: "the `#alias` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo
@@ -1508,13 +1756,27 @@ foo #alias "Foo"
 `,
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
+		{
+			caption: "the `#alias` directive cannot take a directive group parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo
+    ;
+
+foo #alias ()
+    : 'foo';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
 	}
 
-	modeTests := []*specErrTest{
+	modeDirTests := []*specErrTest{
 		{
 			caption: "the `#mode` directive needs an ID parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1530,7 +1792,7 @@ bar #mode
 		{
 			caption: "the `#mode` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1546,7 +1808,7 @@ bar #mode "mode_1"
 		{
 			caption: "the `#mode` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1559,13 +1821,29 @@ bar #mode 'mode_1'
 `,
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
+		{
+			caption: "the `#mode` directive cannot take a directive group parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo bar
+    ;
+
+foo #push mode_1
+    : 'foo';
+bar #mode ()
+    : 'bar';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
 	}
 
-	pushTests := []*specErrTest{
+	pushDirTests := []*specErrTest{
 		{
 			caption: "the `#push` directive needs an ID parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1581,7 +1859,7 @@ bar #mode mode_1
 		{
 			caption: "the `#push` directive takes just one ID parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1597,7 +1875,7 @@ bar #mode mode_1
 		{
 			caption: "the `#push` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1613,7 +1891,7 @@ bar #mode mode_1
 		{
 			caption: "the `#push` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1626,13 +1904,29 @@ bar #mode mode_1
 `,
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
+		{
+			caption: "the `#push` directive cannot take a directive group parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo bar
+    ;
+
+foo #push ()
+    : 'foo';
+bar #mode mode_1
+    : 'bar';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
 	}
 
-	popTests := []*specErrTest{
+	popDirTests := []*specErrTest{
 		{
 			caption: "the `#pop` directive cannot take an ID parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar baz
@@ -1650,7 +1944,7 @@ baz #pop mode_1
 		{
 			caption: "the `#pop` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar baz
@@ -1668,7 +1962,7 @@ baz #pop "mode_1"
 		{
 			caption: "the `#pop` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar baz
@@ -1683,13 +1977,31 @@ baz #pop 'mode_1'
 `,
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
+		{
+			caption: "the `#pop` directive cannot take a directive parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo bar baz
+    ;
+
+foo #push mode_1
+    : 'foo';
+bar #mode mode_1
+    : 'bar';
+baz #pop ()
+    : 'baz';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
 	}
 
 	skipDirTests := []*specErrTest{
 		{
 			caption: "the `#skip` directive cannot take an ID parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1705,7 +2017,7 @@ bar
 		{
 			caption: "the `#skip` directive cannot take a pattern parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1721,7 +2033,7 @@ bar
 		{
 			caption: "the `#skip` directive cannot take a string parameter",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1735,9 +2047,25 @@ bar
 			errs: []*SemanticError{semErrDirInvalidParam},
 		},
 		{
+			caption: "the `#skip` directive cannot take a directive group parameter",
+			specSrc: `
+#name test;
+
+s
+    : foo bar
+    ;
+
+foo #skip ()
+    : 'foo';
+bar
+    : 'bar';
+`,
+			errs: []*SemanticError{semErrDirInvalidParam},
+		},
+		{
 			caption: "a terminal symbol used in productions cannot have the skip directive",
 			specSrc: `
-%name test
+#name test;
 
 s
     : foo bar
@@ -1754,18 +2082,19 @@ bar
 
 	var tests []*specErrTest
 	tests = append(tests, prodTests...)
-	tests = append(tests, nameTests...)
-	tests = append(tests, leftTests...)
-	tests = append(tests, rightTests...)
+	tests = append(tests, nameDirTests...)
+	tests = append(tests, precDirTests...)
+	tests = append(tests, leftDirTests...)
+	tests = append(tests, rightDirTests...)
 	tests = append(tests, errorSymTests...)
 	tests = append(tests, astDirTests...)
-	tests = append(tests, precDirTests...)
+	tests = append(tests, altPrecDirTests...)
 	tests = append(tests, recoverDirTests...)
 	tests = append(tests, fragmentTests...)
 	tests = append(tests, aliasDirTests...)
-	tests = append(tests, modeTests...)
-	tests = append(tests, pushTests...)
-	tests = append(tests, popTests...)
+	tests = append(tests, modeDirTests...)
+	tests = append(tests, pushDirTests...)
+	tests = append(tests, popDirTests...)
 	tests = append(tests, skipDirTests...)
 	for _, test := range tests {
 		t.Run(test.caption, func(t *testing.T) {
diff --git a/grammar/lalr1_test.go b/grammar/lalr1_test.go
index beb2707..94dfd65 100644
--- a/grammar/lalr1_test.go
+++ b/grammar/lalr1_test.go
@@ -10,7 +10,7 @@ import (
 func TestGenLALR1Automaton(t *testing.T) {
 	// This grammar belongs to LALR(1) class, not SLR(1).
 	src := `
-%name test
+#name test;
 
 S: L eq R | R;
 L: ref R | id;
diff --git a/grammar/lr0_test.go b/grammar/lr0_test.go
index cde3f0a..1b20d78 100644
--- a/grammar/lr0_test.go
+++ b/grammar/lr0_test.go
@@ -17,7 +17,7 @@ type expectedLRState struct {
 
 func TestGenLR0Automaton(t *testing.T) {
 	src := `
-%name test
+#name test;
 
 expr
     : expr add term
@@ -227,7 +227,7 @@ id: "[A-Za-z_][0-9A-Za-z_]*";
 
 func TestLR0AutomatonContainingEmptyProduction(t *testing.T) {
 	src := `
-%name test
+#name test;
 
 s
     : foo bar
diff --git a/grammar/parsing_table_test.go b/grammar/parsing_table_test.go
index 833a4d4..522ec1c 100644
--- a/grammar/parsing_table_test.go
+++ b/grammar/parsing_table_test.go
@@ -16,7 +16,7 @@ type expectedState struct {
 
 func TestGenLALRParsingTable(t *testing.T) {
 	src := `
-%name test
+#name test;
 
 S: L eq R | R;
 L: ref R | id;
@@ -288,7 +288,7 @@ id: "[A-Za-z0-9_]+";
 
 func TestGenSLRParsingTable(t *testing.T) {
 	src := `
-%name test
+#name test;
 
 expr
     : expr add term
diff --git a/grammar/semantic_error.go b/grammar/semantic_error.go
index c81cb5f..a843719 100644
--- a/grammar/semantic_error.go
+++ b/grammar/semantic_error.go
@@ -15,9 +15,7 @@ func (e *SemanticError) Error() string {
 }
 
 var (
-	semErrMDInvalidName       = newSemanticError("invalid meta data name")
-	semErrMDInvalidParam      = newSemanticError("invalid parameter")
-	semErrMDMissingName       = newSemanticError("name is missing")
+	semErrNoGrammarName       = newSemanticError("name is missing")
 	semErrDuplicateAssoc      = newSemanticError("associativity and precedence cannot be specified multiple times for a symbol")
 	semErrUndefinedPrec       = newSemanticError("symbol must has precedence")
 	semErrUnusedProduction    = newSemanticError("unused production")
diff --git a/grammar/slr1_test.go b/grammar/slr1_test.go
index 954446f..6748802 100644
--- a/grammar/slr1_test.go
+++ b/grammar/slr1_test.go
@@ -9,7 +9,7 @@ import (
 
 func TestGenSLR1Automaton(t *testing.T) {
 	src := `
-%name test
+#name test;
 
 expr
     : expr add term
diff --git a/spec/lexer.go b/spec/lexer.go
index f9ad871..2459c40 100644
--- a/spec/lexer.go
+++ b/spec/lexer.go
@@ -25,7 +25,8 @@ const (
 	tokenKindLabelMarker     = tokenKind("@")
 	tokenKindDirectiveMarker = tokenKind("#")
 	tokenKindExpantion       = tokenKind("...")
-	tokenKindMetaDataMarker  = tokenKind("%")
+	tokenKindLParen          = tokenKind("(")
+	tokenKindRParen          = tokenKind(")")
 	tokenKindNewline         = tokenKind("newline")
 	tokenKindEOF             = tokenKind("eof")
 	tokenKindInvalid         = tokenKind("invalid")
@@ -265,8 +266,10 @@ func (l *lexer) lexAndSkipWSs() (*token, error) {
 		return newSymbolToken(tokenKindDirectiveMarker, newPosition(tok.Row+1, tok.Col+1)), nil
 	case KindIDExpansion:
 		return newSymbolToken(tokenKindExpantion, newPosition(tok.Row+1, tok.Col+1)), nil
-	case KindIDMetadataMarker:
-		return newSymbolToken(tokenKindMetaDataMarker, newPosition(tok.Row+1, tok.Col+1)), nil
+	case KindIDLParen:
+		return newSymbolToken(tokenKindLParen, newPosition(tok.Row+1, tok.Col+1)), nil
+	case KindIDRParen:
+		return newSymbolToken(tokenKindRParen, newPosition(tok.Row+1, tok.Col+1)), nil
 	default:
 		return newInvalidToken(string(tok.Lexeme), newPosition(tok.Row+1, tok.Col+1)), nil
 	}
diff --git a/spec/lexer_test.go b/spec/lexer_test.go
index 4fab8db..621eff5 100644
--- a/spec/lexer_test.go
+++ b/spec/lexer_test.go
@@ -36,7 +36,7 @@ func TestLexer_Run(t *testing.T) {
 	}{
 		{
 			caption: "the lexer can recognize all kinds of tokens",
-			src:     `id"terminal"'string':|;@...#%`,
+			src:     `id"terminal"'string':|;@...#()`,
 			tokens: []*token{
 				idTok("id"),
 				termPatTok("terminal"),
@@ -47,7 +47,8 @@ func TestLexer_Run(t *testing.T) {
 				symTok(tokenKindLabelMarker),
 				symTok(tokenKindExpantion),
 				symTok(tokenKindDirectiveMarker),
-				symTok(tokenKindMetaDataMarker),
+				symTok(tokenKindLParen),
+				symTok(tokenKindRParen),
 				newEOFToken(),
 			},
 		},
diff --git a/spec/lexspec.json b/spec/lexspec.json
index ff8ff0d..6a11a4a 100644
--- a/spec/lexspec.json
+++ b/spec/lexspec.json
@@ -118,8 +118,12 @@
 			"pattern": "#"
 		},
 		{
-			"kind": "metadata_marker",
-			"pattern": "%"
+			"kind": "l_paren",
+			"pattern": "\\("
+		},
+		{
+			"kind": "r_paren",
+			"pattern": "\\)"
 		}
 	]
 }
diff --git a/spec/parser.go b/spec/parser.go
index a1d23f0..3b5907e 100644
--- a/spec/parser.go
+++ b/spec/parser.go
@@ -9,7 +9,7 @@ import (
 )
 
 type RootNode struct {
-	MetaData       []*DirectiveNode
+	Directives     []*DirectiveNode
 	Productions    []*ProductionNode
 	LexProductions []*ProductionNode
 	Fragments      []*FragmentNode
@@ -58,6 +58,7 @@ type ParameterNode struct {
 	ID        string
 	Pattern   string
 	String    string
+	Group     []*DirectiveNode
 	Expansion bool
 	Pos       Position
 }
@@ -134,14 +135,14 @@ func (p *parser) parseRoot() *RootNode {
 		}
 	}()
 
-	var metadata []*DirectiveNode
+	var dirs []*DirectiveNode
 	var prods []*ProductionNode
 	var lexProds []*ProductionNode
 	var fragments []*FragmentNode
 	for {
-		md := p.parseMetaData()
-		if md != nil {
-			metadata = append(metadata, md)
+		dir := p.parseTopLevelDirective()
+		if dir != nil {
+			dirs = append(dirs, dir)
 			continue
 		}
 
@@ -167,14 +168,14 @@ func (p *parser) parseRoot() *RootNode {
 	}
 
 	return &RootNode{
-		MetaData:       metadata,
+		Directives:     dirs,
 		Productions:    prods,
 		LexProductions: lexProds,
 		Fragments:      fragments,
 	}
 }
 
-func (p *parser) parseMetaData() *DirectiveNode {
+func (p *parser) parseTopLevelDirective() *DirectiveNode {
 	defer func() {
 		err := recover()
 		if err == nil {
@@ -187,35 +188,21 @@ func (p *parser) parseMetaData() *DirectiveNode {
 		}
 
 		p.errs = append(p.errs, specErr)
-		p.skipOverTo(tokenKindNewline)
+		p.skipOverTo(tokenKindSemicolon)
 	}()
 
-	p.consume(tokenKindNewline)
-
-	if !p.consume(tokenKindMetaDataMarker) {
+	dir := p.parseDirective()
+	if dir == nil {
 		return nil
 	}
-	mdPos := p.lastTok.pos
 
-	if !p.consume(tokenKindID) {
-		raiseSyntaxError(p.pos.Row, synErrNoMDName)
-	}
-	name := p.lastTok.text
+	p.consume(tokenKindNewline)
 
-	var params []*ParameterNode
-	for {
-		param := p.parseParameter()
-		if param == nil {
-			break
-		}
-		params = append(params, param)
+	if !p.consume(tokenKindSemicolon) {
+		raiseSyntaxError(p.pos.Row, synErrTopLevelDirNoSemicolon)
 	}
 
-	return &DirectiveNode{
-		Name:       name,
-		Parameters: params,
-		Pos:        mdPos,
-	}
+	return dir
 }
 
 func (p *parser) parseFragment() *FragmentNode {
@@ -428,6 +415,8 @@ func (p *parser) parseElement() *ElementNode {
 }
 
 func (p *parser) parseDirective() *DirectiveNode {
+	p.consume(tokenKindNewline)
+
 	if !p.consume(tokenKindDirectiveMarker) {
 		return nil
 	}
@@ -472,6 +461,30 @@ func (p *parser) parseParameter() *ParameterNode {
 			String: p.lastTok.text,
 			Pos:    p.lastTok.pos,
 		}
+	case p.consume(tokenKindLParen):
+		pos := p.lastTok.pos
+		var g []*DirectiveNode
+		for {
+			dir := p.parseDirective()
+			if dir == nil {
+				break
+			}
+			g = append(g, dir)
+		}
+		if !p.consume(tokenKindRParen) {
+			raiseSyntaxError(p.pos.Row, synErrUnclosedDirGroup)
+		}
+		if len(g) == 0 {
+			// Set an empty slice representing an empty directive group to distinguish between the following two cases.
+			//
+			// - #prec (); // vartan allows this case.
+			// - #prec;    // This case will raise an error.
+			g = []*DirectiveNode{}
+		}
+		param = &ParameterNode{
+			Group: g,
+			Pos:   pos,
+		}
 	default:
 		return nil
 	}
diff --git a/spec/parser_test.go b/spec/parser_test.go
index 2a44acd..de2c6f7 100644
--- a/spec/parser_test.go
+++ b/spec/parser_test.go
@@ -8,6 +8,20 @@ import (
 )
 
 func TestParse(t *testing.T) {
+	name := func(param *ParameterNode) *DirectiveNode {
+		return &DirectiveNode{
+			Name:       "name",
+			Parameters: []*ParameterNode{param},
+		}
+	}
+
+	prec := func(param *ParameterNode) *DirectiveNode {
+		return &DirectiveNode{
+			Name:       "prec",
+			Parameters: []*ParameterNode{param},
+		}
+	}
+
 	leftAssoc := func(params ...*ParameterNode) *DirectiveNode {
 		return &DirectiveNode{
 			Name:       "left",
@@ -66,6 +80,11 @@ func TestParse(t *testing.T) {
 		param.Expansion = true
 		return param
 	}
+	group := func(dirs ...*DirectiveNode) *ParameterNode {
+		return &ParameterNode{
+			Group: dirs,
+		}
+	}
 	withParamPos := func(param *ParameterNode, pos Position) *ParameterNode {
 		param.Pos = pos
 		return param
@@ -122,6 +141,82 @@ func TestParse(t *testing.T) {
 		synErr        *SyntaxError
 	}{
 		{
+			caption: "a grammar can contain top-level directives",
+			src: `
+#name test;
+
+#prec (
+    #left a b
+    #right c d
+);
+`,
+			ast: &RootNode{
+				Directives: []*DirectiveNode{
+					withDirPos(
+						name(
+							withParamPos(
+								idParam("test"),
+								newPos(2),
+							),
+						),
+						newPos(2),
+					),
+					withDirPos(
+						prec(
+							withParamPos(
+								group(
+									withDirPos(
+										leftAssoc(
+											withParamPos(
+												idParam("a"),
+												newPos(5),
+											),
+											withParamPos(
+												idParam("b"),
+												newPos(5),
+											),
+										),
+										newPos(5),
+									),
+									withDirPos(
+										rightAssoc(
+											withParamPos(
+												idParam("c"),
+												newPos(6),
+											),
+											withParamPos(
+												idParam("d"),
+												newPos(6),
+											),
+										),
+										newPos(6),
+									),
+								),
+								newPos(4),
+							),
+						),
+						newPos(4),
+					),
+				},
+			},
+		},
+		{
+			caption: "a top-level directive must be followed by ';'",
+			src: `
+#name test
+`,
+			synErr: synErrTopLevelDirNoSemicolon,
+		},
+		{
+			caption: "a directive group must be closed by ')'",
+			src: `
+#prec (
+    #left a b
+;
+`,
+			synErr: synErrUnclosedDirGroup,
+		},
+		{
 			caption: "single production is a valid grammar",
 			src:     `a: "a";`,
 			ast: &RootNode{
@@ -643,10 +738,12 @@ foo
 		{
 			caption: "a grammar can contain left and right associativities",
 			src: `
-%left l1 l2
-%left l3
-%right r1 r2
-%right r3
+#prec (
+    #left l1 l2
+    #left l3
+    #right r1 r2
+    #right r3
+);
 
 s
     : id l1 id l2 id l3 id
@@ -671,33 +768,43 @@ id
     : "[A-Za-z0-9_]+";
 `,
 			ast: &RootNode{
-				MetaData: []*DirectiveNode{
+				Directives: []*DirectiveNode{
 					withDirPos(
-						leftAssoc(
-							withParamPos(idParam("l1"), newPos(2)),
-							withParamPos(idParam("l2"), newPos(2)),
+						prec(
+							withParamPos(
+								group(
+									withDirPos(
+										leftAssoc(
+											withParamPos(idParam("l1"), newPos(3)),
+											withParamPos(idParam("l2"), newPos(3)),
+										),
+										newPos(3),
+									),
+									withDirPos(
+										leftAssoc(
+											withParamPos(idParam("l3"), newPos(4)),
+										),
+										newPos(4),
+									),
+									withDirPos(
+										rightAssoc(
+											withParamPos(idParam("r1"), newPos(5)),
+											withParamPos(idParam("r2"), newPos(5)),
+										),
+										newPos(5),
+									),
+									withDirPos(
+										rightAssoc(
+											withParamPos(idParam("r3"), newPos(6)),
+										),
+										newPos(6),
+									),
+								),
+								newPos(2),
+							),
 						),
 						newPos(2),
 					),
-					withDirPos(
-						leftAssoc(
-							withParamPos(idParam("l3"), newPos(3)),
-						),
-						newPos(3),
-					),
-					withDirPos(
-						rightAssoc(
-							withParamPos(idParam("r1"), newPos(4)),
-							withParamPos(idParam("r2"), newPos(4)),
-						),
-						newPos(4),
-					),
-					withDirPos(
-						rightAssoc(
-							withParamPos(idParam("r3"), newPos(5)),
-						),
-						newPos(5),
-					),
 				},
 				Productions: []*ProductionNode{
 					prod("s",
@@ -756,11 +863,11 @@ func testRootNode(t *testing.T, root, expected *RootNode, checkPosition bool) {
 	if len(root.Productions) != len(expected.Productions) {
 		t.Fatalf("unexpected length of productions; want: %v, got: %v", len(expected.Productions), len(root.Productions))
 	}
-	if len(root.MetaData) != len(expected.MetaData) {
-		t.Fatalf("unexpected length of meta data; want: %v, got: %v", len(expected.MetaData), len(root.MetaData))
+	if len(root.Directives) != len(expected.Directives) {
+		t.Fatalf("unexpected length of top-level directives; want: %v, got: %v", len(expected.Directives), len(root.Directives))
 	}
-	for i, md := range root.MetaData {
-		testDirectives(t, []*DirectiveNode{md}, []*DirectiveNode{expected.MetaData[i]}, true)
+	for i, dir := range root.Directives {
+		testDirectives(t, []*DirectiveNode{dir}, []*DirectiveNode{expected.Directives[i]}, true)
 	}
 	for i, prod := range root.Productions {
 		testProductionNode(t, prod, expected.Productions[i], checkPosition)
diff --git a/spec/syntax_error.go b/spec/syntax_error.go
index fdf9c40..3b44d2d 100644
--- a/spec/syntax_error.go
+++ b/spec/syntax_error.go
@@ -24,14 +24,15 @@ var (
 	synErrEmptyString       = newSyntaxError("a string must include at least one character")
 
 	// syntax errors
-	synErrInvalidToken       = newSyntaxError("invalid token")
-	synErrNoMDName           = newSyntaxError("a metadata name is missing")
-	synErrNoProductionName   = newSyntaxError("a production name is missing")
-	synErrNoColon            = newSyntaxError("the colon must precede alternatives")
-	synErrNoSemicolon        = newSyntaxError("the semicolon is missing at the last of an alternative")
-	synErrLabelWithNoSymbol  = newSyntaxError("a label must follow a symbol")
-	synErrNoLabel            = newSyntaxError("an identifier that represents a label is missing after the label marker @")
-	synErrNoDirectiveName    = newSyntaxError("a directive needs a name")
-	synErrSemicolonNoNewline = newSyntaxError("a semicolon must be followed by a newline")
-	synErrFragmentNoPattern  = newSyntaxError("a fragment needs one pattern element")
+	synErrInvalidToken           = newSyntaxError("invalid token")
+	synErrTopLevelDirNoSemicolon = newSyntaxError("a top-level directive must be followed by ;")
+	synErrNoProductionName       = newSyntaxError("a production name is missing")
+	synErrNoColon                = newSyntaxError("the colon must precede alternatives")
+	synErrNoSemicolon            = newSyntaxError("the semicolon is missing at the last of an alternative")
+	synErrLabelWithNoSymbol      = newSyntaxError("a label must follow a symbol")
+	synErrNoLabel                = newSyntaxError("an identifier that represents a label is missing after the label marker @")
+	synErrNoDirectiveName        = newSyntaxError("a directive needs a name")
+	synErrUnclosedDirGroup       = newSyntaxError("a directive group must be closed by )")
+	synErrSemicolonNoNewline     = newSyntaxError("a semicolon must be followed by a newline")
+	synErrFragmentNoPattern      = newSyntaxError("a fragment needs one pattern element")
 )
diff --git a/spec/vartan_lexer.go b/spec/vartan_lexer.go
index 8c9e7ad..146748a 100644
--- a/spec/vartan_lexer.go
+++ b/spec/vartan_lexer.go
@@ -356,14 +356,15 @@ const (
 	KindIDLabelMarker        KindID = 11
 	KindIDExpansion          KindID = 12
 	KindIDDirectiveMarker    KindID = 13
-	KindIDMetadataMarker     KindID = 14
-	KindIDPattern            KindID = 15
-	KindIDTerminalClose      KindID = 16
-	KindIDEscapeSymbol       KindID = 17
-	KindIDCharSeq            KindID = 18
-	KindIDEscapedQuot        KindID = 19
-	KindIDEscapedBackSlash   KindID = 20
-	KindIDStringLiteralClose KindID = 21
+	KindIDLParen             KindID = 14
+	KindIDRParen             KindID = 15
+	KindIDPattern            KindID = 16
+	KindIDTerminalClose      KindID = 17
+	KindIDEscapeSymbol       KindID = 18
+	KindIDCharSeq            KindID = 19
+	KindIDEscapedQuot        KindID = 20
+	KindIDEscapedBackSlash   KindID = 21
+	KindIDStringLiteralClose KindID = 22
 )
 
 const (
@@ -381,7 +382,8 @@ const (
 	KindNameLabelMarker        = "label_marker"
 	KindNameExpansion          = "expansion"
 	KindNameDirectiveMarker    = "directive_marker"
-	KindNameMetadataMarker     = "metadata_marker"
+	KindNameLParen             = "l_paren"
+	KindNameRParen             = "r_paren"
 	KindNamePattern            = "pattern"
 	KindNameTerminalClose      = "terminal_close"
 	KindNameEscapeSymbol       = "escape_symbol"
@@ -422,8 +424,10 @@ func KindIDToName(id KindID) string {
 		return KindNameExpansion
 	case KindIDDirectiveMarker:
 		return KindNameDirectiveMarker
-	case KindIDMetadataMarker:
-		return KindNameMetadataMarker
+	case KindIDLParen:
+		return KindNameLParen
+	case KindIDRParen:
+		return KindNameRParen
 	case KindIDPattern:
 		return KindNamePattern
 	case KindIDTerminalClose:
@@ -467,7 +471,7 @@ func NewLexSpec() *lexSpec {
 		pop: [][]bool{
 			nil,
 			{
-				false, false, false, false, false, false, false, false, false, false, false, false, false, false, false,
+				false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false,
 			},
 			{
 				false, false, true, false,
@@ -479,7 +483,7 @@ func NewLexSpec() *lexSpec {
 		push: [][]ModeID{
 			nil,
 			{
-				0, 0, 0, 0, 0, 0, 2, 3, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0,
 			},
 			{
 				0, 0, 0, 0,
@@ -505,7 +509,7 @@ func NewLexSpec() *lexSpec {
 			{
 				0, 0, 1, 2, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 				0, 0, 0, 0, 5, 5, 5, 5, 5, 5, 5, 4, 5, 0, 0, 2, 6, 7, 8, 9,
-				10, 11, 12, 13, 14,
+				10, 11, 12, 13, 14, 15,
 			},
 			{
 				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -536,7 +540,8 @@ func NewLexSpec() *lexSpec {
 				KindIDLabelMarker,
 				KindIDExpansion,
 				KindIDDirectiveMarker,
-				KindIDMetadataMarker,
+				KindIDLParen,
+				KindIDRParen,
 			},
 			{
 				KindIDNil,
@@ -568,7 +573,8 @@ func NewLexSpec() *lexSpec {
 			KindNameLabelMarker,
 			KindNameExpansion,
 			KindNameDirectiveMarker,
-			KindNameMetadataMarker,
+			KindNameLParen,
+			KindNameRParen,
 			KindNamePattern,
 			KindNameTerminalClose,
 			KindNameEscapeSymbol,
@@ -587,7 +593,7 @@ func NewLexSpec() *lexSpec {
 			{
 				0, 1, 2, 3, 4, 5, 6, 7, 6, 8, 6, 9, 6, 10, 6, 11, 12, 6, 13, 14,
 				6, 15, 16, 6, 17, 18, 19, 20, 21, 22, 23, 24, 24, 25, 26, 0, 0, 0, 0, 0,
-				0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0,
 			},
 			{
 				0, 1, 2, 3, 2, 4, 2, 5, 2, 6, 2, 7, 8, 2, 9, 10, 2, 11, 12, 2,
@@ -633,7 +639,7 @@ func NewLexSpec() *lexSpec {
 				5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
 				5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
 				5, 5, 5, 5, 5, 1, 1, -1, -1, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-				-1, -1, -1, -1, -1, -1, -1, -1, 1, -1, 1, 1, -1, 1, -1, 1, -1, -1, -1, -1,
+				-1, -1, -1, -1, -1, -1, -1, -1, 1, -1, 1, 1, -1, -1, -1, 1, 1, 1, -1, -1,
 				-1, -1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, -1, -1, -1, -1,
 				1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 				1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, 1, -1, 1, 1, 1, 1, 1, 1, 1,
@@ -978,7 +984,7 @@ func NewLexSpec() *lexSpec {
 				6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
 				6, 6, 6, 6, 7, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 11, 13, 13,
 				15, 18, 18, 18, 21, 2, 35, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-				0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 36, 43, 0, 44, 0, 37, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 36, 43, 0, 0, 0, 37, 44, 45, 0, 0,
 				0, 0, 33, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 38, 40, 0, 0, 0, 0,
 				41, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
 				32, 32, 32, 32, 32, 32, 32, 0, 0, 0, 0, 32, 0, 32, 32, 32, 32, 32, 24, 32,