Remove alias system

Remove unimportant features to tidy up the specification.

5 files changed, 22 insertions, 44 deletions

diff --git a/driver/parser.go b/driver/parser.go
index 14e9752..b7f12ff 100644
--- a/driver/parser.go
+++ b/driver/parser.go
@@ -44,9 +44,6 @@ type Grammar interface {
 	// Terminal retuns a string representaion of a terminal symbol.
 	Terminal(terminal int) string
 
-	// TerminalAlias returns an alias for a terminal.
-	TerminalAlias(terminal int) string
-
 	// ASTAction returns an AST action entries.
 	ASTAction(prod int) []int
 }
@@ -370,11 +367,7 @@ func (p *Parser) searchLookahead(state int) []string {
 			continue
 		}
 
-		if alias := p.gram.TerminalAlias(term); alias != "" {
-			kinds = append(kinds, alias)
-		} else {
-			kinds = append(kinds, p.gram.Terminal(term))
-		}
+		kinds = append(kinds, p.gram.Terminal(term))
 	}
 
 	return kinds
diff --git a/driver/parser_test.go b/driver/parser_test.go
index 215988d..dd58dd5 100644
--- a/driver/parser_test.go
+++ b/driver/parser_test.go
@@ -18,10 +18,6 @@ func termNode(kind string, text string, children ...*Node) *Node {
 	}
 }
 
-func anonTermNode(text string, children ...*Node) *Node {
-	return termNode("", text, children...)
-}
-
 func errorNode() *Node {
 	return &Node{
 		Type:     NodeTypeError,
@@ -50,18 +46,26 @@ func TestParser_Parse(t *testing.T) {
 #name test;
 
 expr
-    : expr '+' term
+    : expr add term
     | term
     ;
 term
-    : term '*' factor
+    : term mul factor
     | factor
     ;
 factor
-    : '(' expr ')'
+    : l_paren expr r_paren
     | id
     ;
 
+add
+    : '+';
+mul
+    : '*';
+l_paren
+    : '(';
+r_paren
+    : ')';
 id
     : "[A-Za-z_][0-9A-Za-z_]*";
 `,
@@ -71,7 +75,7 @@ id
 					nonTermNode("term",
 						nonTermNode("term",
 							nonTermNode("factor",
-								anonTermNode("("),
+								termNode("l_paren", "("),
 								nonTermNode("expr",
 									nonTermNode("expr",
 										nonTermNode("term",
@@ -80,10 +84,10 @@ id
 											),
 										),
 									),
-									anonTermNode("+"),
+									termNode("add", "+"),
 									nonTermNode("term",
 										nonTermNode("factor",
-											anonTermNode("("),
+											termNode("l_paren", "("),
 											nonTermNode("expr",
 												nonTermNode("expr",
 													nonTermNode("term",
@@ -92,27 +96,27 @@ id
 														),
 													),
 												),
-												anonTermNode("+"),
+												termNode("add", "+"),
 												nonTermNode("term",
 													nonTermNode("factor",
 														termNode("id", "c"),
 													),
 												),
 											),
-											anonTermNode(")"),
+											termNode("r_paren", ")"),
 										),
 									),
 								),
-								anonTermNode(")"),
+								termNode("r_paren", ")"),
 							),
 						),
-						anonTermNode("*"),
+						termNode("mul", "*"),
 						nonTermNode("factor",
 							termNode("id", "d"),
 						),
 					),
 				),
-				anonTermNode("+"),
+				termNode("add", "+"),
 				nonTermNode("term",
 					nonTermNode("factor",
 						termNode("id", "e"),
diff --git a/driver/spec.go b/driver/spec.go
index dda1251..e694d0b 100644
--- a/driver/spec.go
+++ b/driver/spec.go
@@ -64,10 +64,6 @@ func (g *grammarImpl) Terminal(terminal int) string {
 	return g.g.ParsingTable.Terminals[terminal]
 }
 
-func (g *grammarImpl) TerminalAlias(terminal int) string {
-	return g.g.LexicalSpecification.Maleeni.KindAliases[terminal]
-}
-
 func (g *grammarImpl) ASTAction(prod int) []int {
 	return g.g.ASTAction.Entries[prod]
 }
diff --git a/driver/syntax_error_test.go b/driver/syntax_error_test.go
index f68f595..ada1fb0 100644
--- a/driver/syntax_error_test.go
+++ b/driver/syntax_error_test.go
@@ -242,7 +242,7 @@ foo
 			},
 		},
 		{
-			caption: "when an anonymous symbol is expected, an expected symbol list contains an alias of the anonymous symbol",
+			caption: "when an anonymous symbol is expected, an expected symbol list contains an auto-generated name with the prefix `x_`",
 			specSrc: `
 #name test;
 
@@ -256,7 +256,7 @@ foo
 			src:   `foobaz`,
 			cause: `baz`,
 			expected: []string{
-				"bar",
+				"x_1",
 			},
 		},
 	}
diff --git a/driver/template.go b/driver/template.go
index 5ff3aa5..87c74f6 100644
--- a/driver/template.go
+++ b/driver/template.go
@@ -147,7 +147,6 @@ type grammarImpl struct {
 	nonTerminals            []string
 	lhsSymbols              []int
 	terminals               []string
-	terminalAliases         []string
 	astActions              [][]int
 }
 
@@ -161,7 +160,6 @@ func NewGrammar() *grammarImpl {
 		nonTerminals:            {{ genNonTerminals }},
 		lhsSymbols:              {{ genLHSSymbols }},
 		terminals:               {{ genTerminals }},
-		terminalAliases:         {{ genTerminalAliases }},
 		astActions:              {{ genASTActions }},
 	}
 }
@@ -218,10 +216,6 @@ func (g *grammarImpl) Terminal(terminal int) string {
 	return g.terminals[terminal]
 }
 
-func (g *grammarImpl) TerminalAlias(terminal int) string {
-	return g.terminalAliases[terminal]
-}
-
 func (g *grammarImpl) ASTAction(prod int) []int {
 	return g.astActions[prod]
 }
@@ -361,15 +355,6 @@ func genGrammarTemplateFuncs(cgram *spec.CompiledGrammar) template.FuncMap {
 			fmt.Fprintf(&b, "}")
 			return b.String()
 		},
-		"genTerminalAliases": func() string {
-			var b strings.Builder
-			fmt.Fprintf(&b, "[]string{\n")
-			for _, v := range cgram.LexicalSpecification.Maleeni.KindAliases {
-				fmt.Fprintf(&b, "%v,\n", strconv.Quote(v))
-			}
-			fmt.Fprintf(&b, "}")
-			return b.String()
-		},
 		"genASTActions": func() string {
 			var b strings.Builder
 			fmt.Fprintf(&b, "[][]int{\n")