Rename spec package to spec/grammar package

1 files changed, 0 insertions, 1096 deletions

diff --git a/spec/parser_test.go b/spec/parser_test.go
deleted file mode 100644
index c7d43de..0000000
--- a/spec/parser_test.go
+++ /dev/null
@@ -1,1096 +0,0 @@
-package spec
-
-import (
-	"strings"
-	"testing"
-
-	verr "github.com/nihei9/vartan/error"
-)
-
-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",
-			Parameters: params,
-		}
-	}
-	rightAssoc := func(params ...*ParameterNode) *DirectiveNode {
-		return &DirectiveNode{
-			Name:       "right",
-			Parameters: params,
-		}
-	}
-	assign := func(params ...*ParameterNode) *DirectiveNode {
-		return &DirectiveNode{
-			Name:       "assign",
-			Parameters: params,
-		}
-	}
-	prod := func(lhs string, alts ...*AlternativeNode) *ProductionNode {
-		return &ProductionNode{
-			LHS: lhs,
-			RHS: alts,
-		}
-	}
-	withProdPos := func(prod *ProductionNode, pos Position) *ProductionNode {
-		prod.Pos = pos
-		return prod
-	}
-	withProdDir := func(prod *ProductionNode, dirs ...*DirectiveNode) *ProductionNode {
-		prod.Directives = dirs
-		return prod
-	}
-	alt := func(elems ...*ElementNode) *AlternativeNode {
-		return &AlternativeNode{
-			Elements: elems,
-		}
-	}
-	withAltPos := func(alt *AlternativeNode, pos Position) *AlternativeNode {
-		alt.Pos = pos
-		return alt
-	}
-	withAltDir := func(alt *AlternativeNode, dirs ...*DirectiveNode) *AlternativeNode {
-		alt.Directives = dirs
-		return alt
-	}
-	dir := func(name string, params ...*ParameterNode) *DirectiveNode {
-		return &DirectiveNode{
-			Name:       name,
-			Parameters: params,
-		}
-	}
-	withDirPos := func(dir *DirectiveNode, pos Position) *DirectiveNode {
-		dir.Pos = pos
-		return dir
-	}
-	idParam := func(id string) *ParameterNode {
-		return &ParameterNode{
-			ID: id,
-		}
-	}
-	ordSymParam := func(id string) *ParameterNode {
-		return &ParameterNode{
-			OrderedSymbol: id,
-		}
-	}
-	exp := func(param *ParameterNode) *ParameterNode {
-		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
-	}
-	id := func(id string) *ElementNode {
-		return &ElementNode{
-			ID: id,
-		}
-	}
-	pat := func(p string) *ElementNode {
-		return &ElementNode{
-			Pattern: p,
-		}
-	}
-	label := func(name string) *LabelNode {
-		return &LabelNode{
-			Name: name,
-		}
-	}
-	withLabelPos := func(label *LabelNode, pos Position) *LabelNode {
-		label.Pos = pos
-		return label
-	}
-	withLabel := func(elem *ElementNode, label *LabelNode) *ElementNode {
-		elem.Label = label
-		return elem
-	}
-	withElemPos := func(elem *ElementNode, pos Position) *ElementNode {
-		elem.Pos = pos
-		return elem
-	}
-	frag := func(lhs string, rhs string) *FragmentNode {
-		return &FragmentNode{
-			LHS: lhs,
-			RHS: rhs,
-		}
-	}
-	withFragmentPos := func(frag *FragmentNode, pos Position) *FragmentNode {
-		frag.Pos = pos
-		return frag
-	}
-	newPos := func(row int) Position {
-		return Position{
-			Row: row,
-			Col: 0,
-		}
-	}
-
-	tests := []struct {
-		caption       string
-		src           string
-		checkPosition bool
-		ast           *RootNode
-		synErr        *SyntaxError
-	}{
-		{
-			caption: "a grammar can contain top-level directives",
-			src: `
-#name test;
-
-#prec (
-    #left a b $x1
-    #right c d $x2
-    #assign e f $x3
-);
-`,
-			ast: &RootNode{
-				Directives: []*DirectiveNode{
-					withDirPos(
-						name(
-							withParamPos(
-								idParam("test"),
-								newPos(2),
-							),
-						),
-						newPos(2),
-					),
-					withDirPos(
-						prec(
-							withParamPos(
-								group(
-									withDirPos(
-										leftAssoc(
-											withParamPos(
-												idParam("a"),
-												newPos(5),
-											),
-											withParamPos(
-												idParam("b"),
-												newPos(5),
-											),
-											withParamPos(
-												ordSymParam("x1"),
-												newPos(5),
-											),
-										),
-										newPos(5),
-									),
-									withDirPos(
-										rightAssoc(
-											withParamPos(
-												idParam("c"),
-												newPos(6),
-											),
-											withParamPos(
-												idParam("d"),
-												newPos(6),
-											),
-											withParamPos(
-												ordSymParam("x2"),
-												newPos(6),
-											),
-										),
-										newPos(6),
-									),
-									withDirPos(
-										assign(
-											withParamPos(
-												idParam("e"),
-												newPos(7),
-											),
-											withParamPos(
-												idParam("f"),
-												newPos(7),
-											),
-											withParamPos(
-												ordSymParam("x3"),
-												newPos(7),
-											),
-										),
-										newPos(7),
-									),
-								),
-								newPos(4),
-							),
-						),
-						newPos(4),
-					),
-				},
-			},
-		},
-		{
-			caption: "a top-level directive must be followed by ';'",
-			src: `
-#name test
-`,
-			synErr: synErrTopLevelDirNoSemicolon,
-		},
-		{
-			caption: "a directive group must be closed by ')'",
-			src: `
-#prec (
-    #left a b
-;
-`,
-			synErr: synErrUnclosedDirGroup,
-		},
-		{
-			caption: "an ordered symbol marker '$' must be followed by and ID",
-			src: `
-#prec (
-    #assign $
-);
-`,
-			synErr: synErrNoOrderedSymbolName,
-		},
-		{
-			caption: "single production is a valid grammar",
-			src:     `a: "a";`,
-			ast: &RootNode{
-				LexProductions: []*ProductionNode{
-					prod("a", alt(pat("a"))),
-				},
-			},
-		},
-		{
-			caption: "multiple productions are a valid grammar",
-			src: `
-e: e "\+|-" t | t;
-t: t "\*|/" f | f;
-f: "\(" e ")" | id;
-id: "[A-Za-z_][0-9A-Za-z_]*";
-`,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					prod("e",
-						alt(id("e"), pat(`\+|-`), id("t")),
-						alt(id("t")),
-					),
-					prod("t",
-						alt(id("t"), pat(`\*|/`), id("f")),
-						alt(id("f")),
-					),
-					prod("f",
-						alt(pat(`\(`), id("e"), pat(`)`)),
-						alt(id("id")),
-					),
-				},
-				LexProductions: []*ProductionNode{
-					prod("id",
-						alt(pat(`[A-Za-z_][0-9A-Za-z_]*`)),
-					),
-				},
-			},
-		},
-		{
-			caption: "productions can contain the empty alternative",
-			src: `
-a: "foo" | ;
-b: | "bar";
-c: ;
-`,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					prod("a",
-						alt(pat(`foo`)),
-						alt(),
-					),
-					prod("b",
-						alt(),
-						alt(pat(`bar`)),
-					),
-					prod("c",
-						alt(),
-					),
-				},
-			},
-		},
-		{
-			caption: "a production cannot contain an ordered symbol",
-			src: `
-a: $x;
-`,
-			synErr: synErrNoSemicolon,
-		},
-		{
-			caption: "`fragment` is a reserved word",
-			src:     `fragment: 'fragment';`,
-			synErr:  synErrNoProductionName,
-		},
-		{
-			caption: "when a source contains an unknown token, the parser raises a syntax error",
-			src:     `a: !;`,
-			synErr:  synErrInvalidToken,
-		},
-		{
-			caption: "a production must have its name as the first element",
-			src:     `: "a";`,
-			synErr:  synErrNoProductionName,
-		},
-		{
-			caption: "':' must precede an alternative",
-			src:     `a "a";`,
-			synErr:  synErrNoColon,
-		},
-		{
-			caption: "';' must follow a production",
-			src:     `a: "a"`,
-			synErr:  synErrNoSemicolon,
-		},
-		{
-			caption: "';' can only appear at the end of a production",
-			src:     `;`,
-			synErr:  synErrNoProductionName,
-		},
-		{
-			caption: "a grammar can contain fragments",
-			src: `
-s
-    : tagline
-    ;
-tagline: "\f{words} IS OUT THERE.";
-fragment words: "[A-Za-z\u{0020}]+";
-`,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					prod("s",
-						alt(id("tagline")),
-					),
-				},
-				LexProductions: []*ProductionNode{
-					prod("tagline",
-						alt(pat(`\f{words} IS OUT THERE.`)),
-					),
-				},
-				Fragments: []*FragmentNode{
-					frag("words", `[A-Za-z\u{0020}]+`),
-				},
-			},
-		},
-		{
-			caption: "the lexer treats consecutive lines as a single token but can count lines correctly",
-			src: `// This line precedes line comments and blank lines.
-// This is a line comment.
-
-
-s
-    : foo
-    ;
-
-
-// This line is sandwiched between blank lines.
-
-
-foo: 'foo';
-`,
-			checkPosition: true,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					withProdPos(
-						prod("s",
-							withAltPos(
-								alt(
-									withElemPos(
-										id("foo"),
-										newPos(6),
-									),
-								),
-								newPos(6),
-							),
-						),
-						newPos(5),
-					),
-				},
-				LexProductions: []*ProductionNode{
-					withProdPos(
-						prod("foo",
-							withAltPos(
-								alt(
-									withElemPos(
-										pat(`foo`),
-										newPos(13),
-									),
-								),
-								newPos(13),
-							),
-						),
-						newPos(13),
-					),
-				},
-			},
-		},
-		{
-			caption: "a grammar can contain production directives and alternative directives",
-			src: `
-mode_tran_seq
-    : mode_tran_seq mode_tran
-    | mode_tran
-    ;
-mode_tran
-    : push_m1
-    | push_m2
-    | pop_m1
-    | 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 #skip
-    : "\u{0020}+";
-`,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					prod("mode_tran_seq",
-						alt(id("mode_tran_seq"), id("mode_tran")),
-						alt(id("mode_tran")),
-					),
-					prod("mode_tran",
-						alt(id("push_m1")),
-						alt(id("push_m2")),
-						alt(id("pop_m1")),
-						alt(id("pop_m2")),
-					),
-				},
-				LexProductions: []*ProductionNode{
-					withProdDir(
-						prod("push_m1",
-							alt(pat(`->`)),
-						),
-						dir("push", idParam("m1")),
-					),
-					withProdDir(
-						prod("push_m2",
-							alt(pat(`-->`)),
-						),
-						dir("mode", idParam("m1")),
-						dir("push", idParam("m2")),
-					),
-					withProdDir(
-						prod("pop_m1",
-							alt(pat(`<-`)),
-						),
-						dir("mode", idParam("m1")),
-						dir("pop"),
-					),
-					withProdDir(
-						prod("pop_m2",
-							alt(pat(`<--`)),
-						),
-						dir("mode", idParam("m2")),
-						dir("pop"),
-					),
-					withProdDir(
-						prod("whitespace",
-							alt(pat(`\u{0020}+`)),
-						),
-						dir("mode", idParam("default"), idParam("m1"), idParam("m2")),
-						dir("skip"),
-					),
-				},
-			},
-		},
-		{
-			caption: "an alternative of a production can have multiple alternative directives",
-			src: `
-s
-    : foo bar #prec baz #ast foo bar
-    ;
-`,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					prod("s",
-						withAltDir(
-							alt(id("foo"), id("bar")),
-							dir("prec", idParam("baz")),
-							dir("ast", idParam("foo"), idParam("bar")),
-						),
-					),
-				},
-			},
-		},
-		{
-			caption: "a lexical production can have multiple production directives",
-			src: `
-foo #mode a #push b
-    : 'foo';
-`,
-			ast: &RootNode{
-				LexProductions: []*ProductionNode{
-					withProdDir(
-						prod("foo",
-							alt(pat("foo")),
-						),
-						dir("mode", idParam("a")),
-						dir("push", idParam("b")),
-					),
-				},
-			},
-		},
-		{
-			caption: "a production must be followed by a newline",
-			src: `
-s: foo; foo: "foo";
-`,
-			synErr: synErrSemicolonNoNewline,
-		},
-		{
-			caption: "a grammar can contain 'ast' directives and expansion operator",
-			src: `
-s
-    : foo bar_list #ast foo bar_list
-    ;
-bar_list
-    : bar_list bar #ast bar_list... bar
-    | bar          #ast bar
-    ;
-foo: "foo";
-bar: "bar";
-`,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					prod("s",
-						withAltDir(
-							alt(id("foo"), id("bar_list")),
-							dir("ast", idParam("foo"), idParam("bar_list")),
-						),
-					),
-					prod("bar_list",
-						withAltDir(
-							alt(id("bar_list"), id("bar")),
-							dir("ast", exp(idParam("bar_list")), idParam("bar")),
-						),
-						withAltDir(
-							alt(id("bar")),
-							dir("ast", idParam("bar")),
-						),
-					),
-				},
-				LexProductions: []*ProductionNode{
-					prod("foo",
-						alt(pat("foo")),
-					),
-					prod("bar",
-						alt(pat("bar")),
-					),
-				},
-			},
-		},
-		{
-			caption: "an expansion operator must be preceded by an identifier",
-			src: `
-s
-    : foo #ast ...
-    ;
-`,
-			synErr: synErrStrayExpOp,
-		},
-		{
-			caption: "an expansion operator must be preceded by an identifier",
-			src: `
-a
-    : foo #ast ... foo
-    ;
-`,
-			synErr: synErrStrayExpOp,
-		},
-		{
-			caption: "an expansion operator cannot be applied to a pattern",
-			src: `
-a
-    : "foo" #ast "foo"...
-    ;
-`,
-			synErr: synErrInvalidExpOperand,
-		},
-		{
-			caption: "an expansion operator cannot be applied to a string",
-			src: `
-a
-    : 'foo' #ast 'foo'...
-    ;
-`,
-			synErr: synErrInvalidExpOperand,
-		},
-		{
-			caption: "an expansion operator cannot be applied to an ordered symbol",
-			src: `
-a
-    : foo #ast $foo...
-    ;
-`,
-			synErr: synErrInvalidExpOperand,
-		},
-		{
-			caption: "an expansion operator cannot be applied to a directive group",
-			src: `
-a
-    : foo #ast ()...
-    ;
-`,
-			synErr: synErrInvalidExpOperand,
-		},
-		{
-			caption: "an AST has node positions",
-			src: `
-exp
-    : exp "\+" id #ast exp id
-    | id
-    ;
-
-whitespace #skip
-    : "\u{0020}+";
-id
-    : "\f{letter}(\f{letter}|\f{number})*";
-fragment letter
-    : "[A-Za-z_]";
-fragment number
-    : "[0-9]";
-`,
-			checkPosition: true,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					withProdPos(
-						prod("exp",
-							withAltPos(
-								withAltDir(
-									alt(
-										withElemPos(id("exp"), newPos(3)),
-										withElemPos(pat(`\+`), newPos(3)),
-										withElemPos(id("id"), newPos(3)),
-									),
-									withDirPos(
-										dir("ast",
-											withParamPos(idParam("exp"), newPos(3)),
-											withParamPos(idParam("id"), newPos(3)),
-										),
-										newPos(3),
-									),
-								),
-								newPos(3),
-							),
-							withAltPos(
-								alt(
-									withElemPos(id("id"), newPos(4)),
-								),
-								newPos(4),
-							),
-						),
-						newPos(2),
-					),
-				},
-				LexProductions: []*ProductionNode{
-					withProdPos(
-						withProdDir(
-							prod("whitespace",
-								withAltPos(
-									alt(
-										withElemPos(
-											pat(`\u{0020}+`),
-											newPos(8),
-										),
-									),
-									newPos(8),
-								),
-							),
-							withDirPos(
-								dir("skip"),
-								newPos(7),
-							),
-						),
-						newPos(7),
-					),
-					withProdPos(
-						prod("id",
-							withAltPos(
-								alt(
-									withElemPos(
-										pat(`\f{letter}(\f{letter}|\f{number})*`),
-										newPos(10),
-									),
-								),
-								newPos(10),
-							),
-						),
-						newPos(9),
-					),
-				},
-				Fragments: []*FragmentNode{
-					withFragmentPos(
-						frag("letter", "[A-Za-z_]"),
-						newPos(11),
-					),
-					withFragmentPos(
-						frag("number", "[0-9]"),
-						newPos(13),
-					),
-				},
-			},
-		},
-		{
-			caption: "a symbol can have a label",
-			src: `
-expr
-    : term@lhs add term@rhs
-    ;
-`,
-			ast: &RootNode{
-				Productions: []*ProductionNode{
-					withProdPos(
-						prod("expr",
-							withAltPos(
-								alt(
-									withElemPos(
-										withLabel(
-											id("term"),
-											withLabelPos(
-												label("lhs"),
-												newPos(3),
-											),
-										),
-										newPos(3),
-									),
-									withElemPos(
-										id("add"),
-										newPos(3),
-									),
-									withElemPos(
-										withLabel(
-											id("term"),
-											withLabelPos(
-												label("rhs"),
-												newPos(3),
-											),
-										),
-										newPos(3),
-									),
-								),
-								newPos(3),
-							),
-						),
-						newPos(2),
-					),
-				},
-			},
-		},
-		{
-			caption: "a label must be an identifier, not a string",
-			src: `
-foo
-    : bar@'baz'
-    ;
-`,
-			synErr: synErrNoLabel,
-		},
-		{
-			caption: "a label must be an identifier, not a pattern",
-			src: `
-foo
-    : bar@"baz"
-    ;
-`,
-			synErr: synErrNoLabel,
-		},
-		{
-			caption: "the symbol marker @ must be followed by an identifier",
-			src: `
-foo
-    : bar@
-    ;
-`,
-			synErr: synErrNoLabel,
-		},
-		{
-			caption: "a symbol cannot have more than or equal to two labels",
-			src: `
-foo
-    : bar@baz@bra
-    ;
-`,
-			synErr: synErrLabelWithNoSymbol,
-		},
-		{
-			caption: "a label must follow a symbol",
-			src: `
-foo
-    : @baz
-    ;
-`,
-			synErr: synErrLabelWithNoSymbol,
-		},
-		{
-			caption: "a grammar can contain left and right associativities",
-			src: `
-#prec (
-    #left l1 l2
-    #left l3
-    #right r1 r2
-    #right r3
-);
-
-s
-    : id l1 id l2 id l3 id
-    | id r1 id r2 id r3 id
-    ;
-
-whitespaces #skip
-    : "[\u{0009}\u{0020}]+";
-l1
-    : 'l1';
-l2
-    : 'l2';
-l3
-    : 'l3';
-r1
-    : 'r1';
-r2
-    : 'r2';
-r3
-    : 'r3';
-id
-    : "[A-Za-z0-9_]+";
-`,
-			ast: &RootNode{
-				Directives: []*DirectiveNode{
-					withDirPos(
-						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),
-					),
-				},
-				Productions: []*ProductionNode{
-					prod("s",
-						alt(id(`id`), id(`l1`), id(`id`), id(`l2`), id(`id`), id(`l3`), id(`id`)),
-						alt(id(`id`), id(`r1`), id(`id`), id(`r2`), id(`id`), id(`r3`), id(`id`)),
-					),
-				},
-				LexProductions: []*ProductionNode{
-					withProdDir(
-						prod("whitespaces",
-							alt(pat(`[\u{0009}\u{0020}]+`)),
-						),
-						dir("skip"),
-					),
-					prod("l1", alt(pat(`l1`))),
-					prod("l2", alt(pat(`l2`))),
-					prod("l3", alt(pat(`l3`))),
-					prod("r1", alt(pat(`r1`))),
-					prod("r2", alt(pat(`r2`))),
-					prod("r3", alt(pat(`r3`))),
-					prod("id", alt(pat(`[A-Za-z0-9_]+`))),
-				},
-			},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.caption, func(t *testing.T) {
-			ast, err := Parse(strings.NewReader(tt.src))
-			if tt.synErr != nil {
-				synErrs, ok := err.(verr.SpecErrors)
-				if !ok {
-					t.Fatalf("unexpected error; want: %v, got: %v", tt.synErr, err)
-				}
-				synErr := synErrs[0]
-				if tt.synErr != synErr.Cause {
-					t.Fatalf("unexpected error; want: %v, got: %v", tt.synErr, synErr.Cause)
-				}
-				if ast != nil {
-					t.Fatalf("AST must be nil")
-				}
-			} else {
-				if err != nil {
-					t.Fatalf("unexpected error: %v", err)
-				}
-				if ast == nil {
-					t.Fatalf("AST must be non-nil")
-				}
-				testRootNode(t, ast, tt.ast, tt.checkPosition)
-			}
-		})
-	}
-}
-
-func testRootNode(t *testing.T, root, expected *RootNode, checkPosition bool) {
-	t.Helper()
-	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.Directives) != len(expected.Directives) {
-		t.Fatalf("unexpected length of top-level directives; want: %v, got: %v", len(expected.Directives), len(root.Directives))
-	}
-	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)
-	}
-	for i, prod := range root.LexProductions {
-		testProductionNode(t, prod, expected.LexProductions[i], checkPosition)
-	}
-	for i, frag := range root.Fragments {
-		testFragmentNode(t, frag, expected.Fragments[i], checkPosition)
-	}
-}
-
-func testProductionNode(t *testing.T, prod, expected *ProductionNode, checkPosition bool) {
-	t.Helper()
-	if len(expected.Directives) != len(prod.Directives) {
-		t.Fatalf("unexpected directive count; want: %v directives, got: %v directives", len(expected.Directives), len(prod.Directives))
-	}
-	if len(expected.Directives) > 0 {
-		testDirectives(t, prod.Directives, expected.Directives, checkPosition)
-	}
-	if prod.LHS != expected.LHS {
-		t.Fatalf("unexpected LHS; want: %v, got: %v", expected.LHS, prod.LHS)
-	}
-	if len(prod.RHS) != len(expected.RHS) {
-		t.Fatalf("unexpected length of an RHS; want: %v, got: %v", len(expected.RHS), len(prod.RHS))
-	}
-	for i, alt := range prod.RHS {
-		testAlternativeNode(t, alt, expected.RHS[i], checkPosition)
-	}
-	if checkPosition {
-		testPosition(t, prod.Pos, expected.Pos)
-	}
-}
-
-func testFragmentNode(t *testing.T, frag, expected *FragmentNode, checkPosition bool) {
-	t.Helper()
-	if frag.LHS != expected.LHS {
-		t.Fatalf("unexpected LHS; want: %v, got: %v", expected.LHS, frag.LHS)
-	}
-	if frag.RHS != expected.RHS {
-		t.Fatalf("unexpected RHS; want: %v, got: %v", expected.RHS, frag.RHS)
-	}
-	if checkPosition {
-		testPosition(t, frag.Pos, expected.Pos)
-	}
-}
-
-func testAlternativeNode(t *testing.T, alt, expected *AlternativeNode, checkPosition bool) {
-	t.Helper()
-	if len(alt.Elements) != len(expected.Elements) {
-		t.Fatalf("unexpected length of elements; want: %v, got: %v", len(expected.Elements), len(alt.Elements))
-	}
-	for i, elem := range alt.Elements {
-		testElementNode(t, elem, expected.Elements[i], checkPosition)
-	}
-	if len(alt.Directives) != len(expected.Directives) {
-		t.Fatalf("unexpected alternative directive count; want: %v directive, got: %v directive", len(expected.Directives), len(alt.Directives))
-	}
-	if len(alt.Directives) > 0 {
-		testDirectives(t, alt.Directives, expected.Directives, checkPosition)
-	}
-	if checkPosition {
-		testPosition(t, alt.Pos, expected.Pos)
-	}
-}
-
-func testElementNode(t *testing.T, elem, expected *ElementNode, checkPosition bool) {
-	t.Helper()
-	if elem.ID != expected.ID {
-		t.Fatalf("unexpected ID; want: %v, got: %v", expected.ID, elem.ID)
-	}
-	if elem.Pattern != expected.Pattern {
-		t.Fatalf("unexpected pattern; want: %v, got: %v", expected.Pattern, elem.Pattern)
-	}
-	if checkPosition {
-		testPosition(t, elem.Pos, expected.Pos)
-	}
-}
-
-func testDirectives(t *testing.T, dirs, expected []*DirectiveNode, checkPosition bool) {
-	t.Helper()
-	for i, exp := range expected {
-		dir := dirs[i]
-
-		if exp.Name != dir.Name {
-			t.Fatalf("unexpected directive name; want: %+v, got: %+v", exp.Name, dir.Name)
-		}
-		if len(exp.Parameters) != len(dir.Parameters) {
-			t.Fatalf("unexpected directive parameter; want: %+v, got: %+v", exp.Parameters, dir.Parameters)
-		}
-		for j, expParam := range exp.Parameters {
-			testParameter(t, dir.Parameters[j], expParam, checkPosition)
-		}
-		if checkPosition {
-			testPosition(t, dir.Pos, exp.Pos)
-		}
-	}
-}
-
-func testParameter(t *testing.T, param, expected *ParameterNode, checkPosition bool) {
-	t.Helper()
-	if param.ID != expected.ID {
-		t.Fatalf("unexpected ID parameter; want: %v, got: %v", expected.ID, param.ID)
-	}
-	if param.String != expected.String {
-		t.Fatalf("unexpected string parameter; want: %v, got: %v", expected.ID, param.ID)
-	}
-	if param.Expansion != expected.Expansion {
-		t.Fatalf("unexpected expansion; want: %v, got: %v", expected.Expansion, param.Expansion)
-	}
-	if checkPosition {
-		testPosition(t, param.Pos, expected.Pos)
-	}
-}
-
-func testPosition(t *testing.T, pos, expected Position) {
-	t.Helper()
-	if pos.Row != expected.Row {
-		t.Fatalf("unexpected position want: %+v, got: %+v", expected, pos)
-	}
-}