Move directives given to lexical productions

Move all directives given to lexical productions from alternative directives to production directives.
This change aims to ensure consistency with respect to the syntax of definitions of terminal symbols and non-terminal symbols.

4 files changed, 136 insertions, 71 deletions

diff --git a/driver/conflict_test.go b/driver/conflict_test.go
index f507d4f..1f8914f 100644
--- a/driver/conflict_test.go
+++ b/driver/conflict_test.go
@@ -179,10 +179,14 @@ expr
 	| id
     ;
 
-whitespaces: "[\u{0009}\u{0020}]+" #skip;
-r1: 'r1';
-r2: 'r2';
-id: "[A-Za-z0-9_]+";
+whitespaces #skip
+    : "[\u{0009}\u{0020}]+";
+r1
+    : 'r1';
+r2
+    : 'r2';
+id
+    : "[A-Za-z0-9_]+";
 `,
 			src: `a r2 b r1 c r1 d r2 e`,
 			cst: nonTermNode("expr",
@@ -226,10 +230,14 @@ expr
 	| id
     ;
 
-whitespaces: "[\u{0009}\u{0020}]+" #skip;
-r1: 'r1';
-r2: 'r2';
-id: "[A-Za-z0-9_]+";
+whitespaces #skip
+    : "[\u{0009}\u{0020}]+";
+r1
+    : 'r1';
+r2
+    : 'r2';
+id
+    : "[A-Za-z0-9_]+";
 `,
 			src: `a r2 b r1 c r1 d r2 e`,
 			cst: nonTermNode("expr",
diff --git a/driver/parser_test.go b/driver/parser_test.go
index 9a3e040..9d89efa 100644
--- a/driver/parser_test.go
+++ b/driver/parser_test.go
@@ -245,7 +245,38 @@ bar: "bar";
 a
     : foo
     ;
-foo: "foo" #skip;
+
+foo #skip
+    : "foo";
+`,
+			src:     `foo`,
+			specErr: true,
+		},
+		// A lexical production cannot have alternative productions.
+		{
+			specSrc: `
+%name test
+
+s
+    : foo
+    ;
+
+foo: 'foo' #skip;
+`,
+			src:     `foo`,
+			specErr: true,
+		},
+		// A directive must not be duplicated.
+		{
+			specSrc: `
+%name test
+
+s
+    : foo
+    ;
+
+foo #skip #skip
+    : 'foo';
 `,
 			src:     `foo`,
 			specErr: true,
@@ -265,16 +296,16 @@ mode_tran
     | pop_m2
     ;
 
-push_m1
-    : "->" #push m1;
-push_m2 #mode m1
-    : "-->" #push m2;
-pop_m1 #mode m1
-    : "<-" #pop;
-pop_m2 #mode m2
-    : "<--" #pop;
-whitespace #mode default m1 m2
-    : "\u{0020}+" #skip;
+push_m1 #push m1
+    : "->";
+push_m2 #mode m1 #push m2
+    : "-->";
+pop_m1 #mode m1 #pop
+    : "<-";
+pop_m2 #mode m2 #pop
+    : "<--";
+whitespace #mode default m1 m2 #skip
+    : "\u{0020}+";
 `,
 			src: ` -> --> <-- <- `,
 		},
@@ -301,9 +332,13 @@ bar #mode default
 s
     : foo bar
     ;
-foo: "foo";
-bar: "bar";
-white_space: "[\u{0009}\u{0020}]+" #skip;
+
+foo
+    : "foo";
+bar
+    : "bar";
+white_space #skip
+    : "[\u{0009}\u{0020}]+";
 `,
 			src: `foo bar`,
 		},
@@ -332,8 +367,11 @@ elems
     : elems "," id #ast elems... id
     | id
     ;
-whitespace: "\u{0020}+" #skip;
-id: "[A-Za-z]+";
+
+whitespace #skip
+    : "\u{0020}+";
+id
+    : "[A-Za-z]+";
 `,
 			src: `[Byers, Frohike, Langly]`,
 			cst: nonTermNode("list",
@@ -390,20 +428,6 @@ num: "0|[1-9][0-9]*";
 				),
 			),
 		},
-		// An ast action cannot be applied to a terminal symbol.
-		{
-			specSrc: `
-%name test
-
-s
-    : foo
-    ;
-foo
-    : "foo"@f #ast f...
-    ;
-`,
-			specErr: true,
-		},
 		// The expansion cannot be applied to a terminal symbol.
 		{
 			specSrc: `
@@ -636,12 +660,18 @@ expr
     | int
     ;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-int: "0|[1-9][0-9]*";
-add: '+';
-sub: '-';
-mul: '*';
-div: '/';
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+int
+    : "0|[1-9][0-9]*";
+add
+    : '+';
+sub
+    : '-';
+mul
+    : '*';
+div
+    : '/';
 `,
 			// This source is recognized as the following structure because the production `expr → sub expr`
 			// has the `#prec mul` directive and has the same precedence and associativity of the symbol `mul`.
@@ -729,8 +759,10 @@ s
     | error ';'
     ;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-id: "[A-Za-z_]+";
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+id
+    : "[A-Za-z_]+";
 `,
 			src: `foo bar baz ;`,
 		},
@@ -748,8 +780,10 @@ elem
     | error ';' #recover
     ;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-id: "[A-Za-z_]+";
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+id
+    : "[A-Za-z_]+";
 `,
 			src: `a b c ; d e f ;`,
 		},
@@ -767,8 +801,10 @@ elem
     | error ';' #recover foo
     ;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-id: "[A-Za-z_]+";
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+id
+    : "[A-Za-z_]+";
 `,
 			src:     `a b c ; d e f ;`,
 			specErr: true,
@@ -814,8 +850,10 @@ s
     : foo
     ;
 
-foo: 'foo';
-error: 'error' #skip;
+foo
+    : 'foo';
+error #skip
+    : 'error';
 `,
 			specErr: true,
 		},
diff --git a/driver/semantic_action_test.go b/driver/semantic_action_test.go
index 791b5f0..f9708b7 100644
--- a/driver/semantic_action_test.go
+++ b/driver/semantic_action_test.go
@@ -59,10 +59,14 @@ elem
     : char char char
 	;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-semicolon: ';';
-star: '*';
-char: "[a-z]";
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+semicolon
+    : ';';
+star
+    : '*';
+char
+    : "[a-z]";
 `
 
 	specSrcWithoutErrorProd := `
@@ -76,9 +80,12 @@ elem
     : char char char
 	;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-semicolon: ';';
-char: "[a-z]";
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+semicolon
+    : ';';
+char
+    : "[a-z]";
 `
 
 	tests := []struct {
diff --git a/driver/syntax_error_test.go b/driver/syntax_error_test.go
index a7f363f..329ccef 100644
--- a/driver/syntax_error_test.go
+++ b/driver/syntax_error_test.go
@@ -44,10 +44,14 @@ elem
     : a b c
 	;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-a: 'a';
-b: 'b';
-c: 'c';
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+a
+    : 'a';
+b
+    : 'b';
+c
+    : 'c';
 `,
 			src:         `!; a!; ab!;`,
 			synErrCount: 3,
@@ -66,10 +70,14 @@ elem
     : a b c
 	;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-a: 'a';
-b: 'b';
-c: 'c';
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+a
+    : 'a';
+b
+    : 'b';
+c
+    : 'c';
 `,
 			// After the parser trasits to the error state reading the first invalid symbol ('!'),
 			// the second and third invalid symbols ('!') are ignored.
@@ -90,10 +98,14 @@ elem
     : a b c
 	;
 
-ws: "[\u{0009}\u{0020}]+" #skip;
-a: 'a';
-b: 'b';
-c: 'c';
+ws #skip
+    : "[\u{0009}\u{0020}]+";
+a
+    : 'a';
+b
+    : 'b';
+c
+    : 'c';
 `,
 			src:         `!**; a!**; ab!**; abc!`,
 			synErrCount: 4,