diff options
Diffstat (limited to 'grammar/grammar.go')
| -rw-r--r-- | grammar/grammar.go | 47 |
1 files changed, 36 insertions, 11 deletions
diff --git a/grammar/grammar.go b/grammar/grammar.go index 27fafc9..b911ee2 100644 --- a/grammar/grammar.go +++ b/grammar/grammar.go @@ -73,6 +73,7 @@ const reservedSymbolNameError = "error" type Grammar struct { lexSpec *mlspec.LexSpec skipLexKinds []mlspec.LexKindName + kindAliases map[symbol]string sym2AnonPat map[symbol]string productionSet *productionSet augmentedStartSymbol symbol @@ -158,6 +159,7 @@ func (b *GrammarBuilder) Build() (*Grammar, error) { return &Grammar{ lexSpec: symTabAndLexSpec.lexSpec, skipLexKinds: symTabAndLexSpec.skip, + kindAliases: symTabAndLexSpec.aliases, sym2AnonPat: symTabAndLexSpec.sym2AnonPat, productionSet: prodsAndActs.prods, augmentedStartSymbol: prodsAndActs.augStartSym, @@ -269,6 +271,7 @@ type symbolTableAndLexSpec struct { errSym symbol skip []mlspec.LexKindName skipSyms []string + aliases map[symbol]string } func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolTableAndLexSpec, error) { @@ -332,6 +335,7 @@ func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolT skipKinds := []mlspec.LexKindName{} skipSyms := []string{} + aliases := map[symbol]string{} for _, prod := range root.LexProductions { if sym, exist := symTab.toSymbol(prod.LHS); exist { if sym == errSym { @@ -352,12 +356,12 @@ func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolT continue } - _, err := symTab.registerTerminalSymbol(prod.LHS) + lhsSym, err := symTab.registerTerminalSymbol(prod.LHS) if err != nil { return nil, err } - entry, skip, specErr, err := genLexEntry(prod) + entry, skip, alias, specErr, err := genLexEntry(prod) if err != nil { return nil, err } @@ -369,6 +373,9 @@ func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolT skipKinds = append(skipKinds, mlspec.LexKindName(prod.LHS)) skipSyms = append(skipSyms, prod.LHS) } + if alias != "" { + aliases[lhsSym] = alias + } entries = append(entries, entry) } @@ -402,17 +409,18 @@ func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolT errSym: errSym, skip: skipKinds, skipSyms: skipSyms, + aliases: aliases, }, nil } -func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecError, error) { +func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, string, *verr.SpecError, error) { var modes []mlspec.LexModeName if prod.Directive != nil { dir := prod.Directive switch dir.Name { case "mode": if len(dir.Parameters) == 0 { - return nil, false, &verr.SpecError{ + return nil, false, "", &verr.SpecError{ Cause: semErrDirInvalidParam, Detail: fmt.Sprintf("'mode' directive needs an ID parameter"), Row: dir.Pos.Row, @@ -421,7 +429,7 @@ func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecE } for _, param := range dir.Parameters { if param.ID == "" { - return nil, false, &verr.SpecError{ + return nil, false, "", &verr.SpecError{ Cause: semErrDirInvalidParam, Detail: fmt.Sprintf("'mode' directive needs an ID parameter"), Row: param.Pos.Row, @@ -431,7 +439,7 @@ func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecE modes = append(modes, mlspec.LexModeName(param.ID)) } default: - return nil, false, &verr.SpecError{ + return nil, false, "", &verr.SpecError{ Cause: semErrDirInvalidName, Detail: dir.Name, Row: dir.Pos.Row, @@ -444,12 +452,13 @@ func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecE var skip bool var push mlspec.LexModeName var pop bool + var alias string if alt.Directive != nil { dir := alt.Directive switch dir.Name { case "skip": if len(dir.Parameters) > 0 { - return nil, false, &verr.SpecError{ + return nil, false, "", &verr.SpecError{ Cause: semErrDirInvalidParam, Detail: fmt.Sprintf("'skip' directive needs no parameter"), Row: dir.Pos.Row, @@ -459,7 +468,7 @@ func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecE skip = true case "push": if len(dir.Parameters) != 1 || dir.Parameters[0].ID == "" { - return nil, false, &verr.SpecError{ + return nil, false, "", &verr.SpecError{ Cause: semErrDirInvalidParam, Detail: fmt.Sprintf("'push' directive needs an ID parameter"), Row: dir.Pos.Row, @@ -469,7 +478,7 @@ func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecE push = mlspec.LexModeName(dir.Parameters[0].ID) case "pop": if len(dir.Parameters) > 0 { - return nil, false, &verr.SpecError{ + return nil, false, "", &verr.SpecError{ Cause: semErrDirInvalidParam, Detail: fmt.Sprintf("'pop' directive needs no parameter"), Row: dir.Pos.Row, @@ -477,8 +486,18 @@ func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecE }, nil } pop = true + case "alias": + if len(dir.Parameters) != 1 || dir.Parameters[0].String == "" { + return nil, false, "", &verr.SpecError{ + Cause: semErrDirInvalidParam, + Detail: fmt.Sprintf("'alias' directive needs a string parameter"), + Row: dir.Pos.Row, + Col: dir.Pos.Col, + }, nil + } + alias = dir.Parameters[0].String default: - return nil, false, &verr.SpecError{ + return nil, false, "", &verr.SpecError{ Cause: semErrDirInvalidName, Detail: dir.Name, Row: dir.Pos.Row, @@ -493,7 +512,7 @@ func genLexEntry(prod *spec.ProductionNode) (*mlspec.LexEntry, bool, *verr.SpecE Pattern: mlspec.LexPattern(alt.Elements[0].Pattern), Push: push, Pop: pop, - }, skip, nil, nil + }, skip, alias, nil, nil } type productionsAndActions struct { @@ -920,6 +939,11 @@ func Compile(gram *Grammar, opts ...CompileOption) (*spec.CompiledGrammar, error return nil, err } + kindAliases := make([]string, gram.symbolTable.termNum.Int()) + for _, sym := range gram.symbolTable.terminalSymbols() { + kindAliases[sym.num().Int()] = gram.kindAliases[sym] + } + nonTerms, err := gram.symbolTable.nonTerminalTexts() if err != nil { return nil, err @@ -1033,6 +1057,7 @@ func Compile(gram *Grammar, opts ...CompileOption) (*spec.CompiledGrammar, error KindToTerminal: kind2Term, TerminalToKind: term2Kind, Skip: skip, + KindAliases: kindAliases, }, }, ParsingTable: &spec.ParsingTable{ |