diff options
Diffstat (limited to 'grammar/grammar.go')
| -rw-r--r-- | grammar/grammar.go | 123 |
1 files changed, 20 insertions, 103 deletions
diff --git a/grammar/grammar.go b/grammar/grammar.go index e2f9ba0..16126ec 100644 --- a/grammar/grammar.go +++ b/grammar/grammar.go @@ -84,7 +84,6 @@ type Grammar struct { name string lexSpec *mlspec.LexSpec skipLexKinds []mlspec.LexKindName - sym2AnonPat map[symbol]string productionSet *productionSet augmentedStartSymbol symbol errorSymbol symbol @@ -211,7 +210,6 @@ func (b *GrammarBuilder) Build() (*Grammar, error) { name: specName, lexSpec: symTabAndLexSpec.lexSpec, skipLexKinds: symTabAndLexSpec.skip, - sym2AnonPat: symTabAndLexSpec.sym2AnonPat, productionSet: prodsAndActs.prods, augmentedStartSymbol: prodsAndActs.augStartSym, errorSymbol: symTabAndLexSpec.errSym, @@ -383,18 +381,14 @@ func collectUserDefinedIDsFromDirective(dir *spec.DirectiveNode) []string { } type symbolTableAndLexSpec struct { - symTab *symbolTable - anonPat2Sym map[string]symbol - sym2AnonPat map[symbol]string - lexSpec *mlspec.LexSpec - errSym symbol - skip []mlspec.LexKindName - skipSyms []string + symTab *symbolTable + lexSpec *mlspec.LexSpec + errSym symbol + skip []mlspec.LexKindName + skipSyms []string } func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolTableAndLexSpec, error) { - // Anonymous patterns take precedence over explicitly defined lexical specifications (named patterns). - // Thus anonymous patterns must be registered to `symTab` and `entries` before named patterns. symTab := newSymbolTable() entries := []*mlspec.LexEntry{} @@ -408,57 +402,6 @@ func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolT errSym = sym } - anonPat2Sym := map[string]symbol{} - sym2AnonPat := map[symbol]string{} - { - knownPats := map[string]struct{}{} - anonPats := []string{} - literalPats := map[string]struct{}{} - for _, prod := range root.Productions { - for _, alt := range prod.RHS { - for _, elem := range alt.Elements { - if elem.Pattern == "" { - continue - } - - var pattern string - if elem.Literally { - pattern = mlspec.EscapePattern(elem.Pattern) - } else { - pattern = elem.Pattern - } - - if _, ok := knownPats[pattern]; ok { - continue - } - - knownPats[pattern] = struct{}{} - anonPats = append(anonPats, pattern) - if elem.Literally { - literalPats[pattern] = struct{}{} - } - } - } - } - - for i, p := range anonPats { - kind := fmt.Sprintf("x_%v", i+1) - - sym, err := symTab.registerTerminalSymbol(kind) - if err != nil { - return nil, err - } - - anonPat2Sym[p] = sym - sym2AnonPat[sym] = p - - entries = append(entries, &mlspec.LexEntry{ - Kind: mlspec.LexKindName(kind), - Pattern: mlspec.LexPattern(p), - }) - } - } - skipKinds := []mlspec.LexKindName{} skipSyms := []string{} for _, prod := range root.LexProductions { @@ -522,9 +465,7 @@ func (b *GrammarBuilder) genSymbolTableAndLexSpec(root *spec.RootNode) (*symbolT } return &symbolTableAndLexSpec{ - symTab: symTab, - anonPat2Sym: anonPat2Sym, - sym2AnonPat: sym2AnonPat, + symTab: symTab, lexSpec: &mlspec.LexSpec{ Entries: entries, }, @@ -652,7 +593,6 @@ type productionsAndActions struct { func (b *GrammarBuilder) genProductionsAndActions(root *spec.RootNode, symTabAndLexSpec *symbolTableAndLexSpec) (*productionsAndActions, error) { symTab := symTabAndLexSpec.symTab - anonPat2Sym := symTabAndLexSpec.anonPat2Sym errSym := symTabAndLexSpec.errSym if len(root.Productions) == 0 { @@ -751,33 +691,15 @@ func (b *GrammarBuilder) genProductionsAndActions(root *spec.RootNode, symTabAnd offsets := map[string]int{} ambiguousIDOffsets := map[string]struct{}{} for i, elem := range alt.Elements { - var sym symbol - if elem.Pattern != "" { - var pattern string - if elem.Literally { - pattern = mlspec.EscapePattern(elem.Pattern) - } else { - pattern = elem.Pattern - } - - var ok bool - sym, ok = anonPat2Sym[pattern] - if !ok { - // All patterns are assumed to be pre-detected, so it's a bug if we cannot find them here. - return nil, fmt.Errorf("pattern '%v' is undefined", pattern) - } - } else { - var ok bool - sym, ok = symTab.toSymbol(elem.ID) - if !ok { - b.errs = append(b.errs, &verr.SpecError{ - Cause: semErrUndefinedSym, - Detail: elem.ID, - Row: elem.Pos.Row, - Col: elem.Pos.Col, - }) - continue LOOP_RHS - } + sym, ok := symTab.toSymbol(elem.ID) + if !ok { + b.errs = append(b.errs, &verr.SpecError{ + Cause: semErrUndefinedSym, + Detail: elem.ID, + Row: elem.Pos.Row, + Col: elem.Pos.Col, + }) + continue LOOP_RHS } altSyms[i] = sym @@ -933,6 +855,9 @@ func (b *GrammarBuilder) genProductionsAndActions(root *spec.RootNode, symTabAnd if param.Expansion { elem := alt.Elements[offset] if elem.Pattern != "" { + // Currently, it is a bug to reach here because it is + // forbidden to have anything other than ID appear in + // production rules. b.errs = append(b.errs, &verr.SpecError{ Cause: semErrDirInvalidParam, Detail: fmt.Sprintf("the expansion symbol cannot be applied to a pattern (%v: \"%v\")", param.ID, elem.Pattern), @@ -1319,13 +1244,6 @@ func Compile(gram *Grammar, opts ...CompileOption) (*spec.CompiledGrammar, *spec if err != nil { return nil, nil, err } - terms := make([]string, len(termTexts)) - for i, t := range termTexts { - // NOTE: For anonymous symbol, `t` is a name with `x_` as a prefix. However, - // this name is not intentionally set by a user, so a message containing this - // name will result in an unfriendly message. - terms[i] = t - } nonTerms, err := gram.symbolTable.nonTerminalTexts() if err != nil { @@ -1353,10 +1271,9 @@ func Compile(gram *Grammar, opts ...CompileOption) (*spec.CompiledGrammar, *spec b := &lrTableBuilder{ automaton: lalr1.lr0Automaton, prods: gram.productionSet, - termCount: len(terms), + termCount: len(termTexts), nonTermCount: len(nonTerms), symTab: gram.symbolTable, - sym2AnonPat: gram.sym2AnonPat, precAndAssoc: gram.precAndAssoc, } tab, err = b.build() @@ -1426,7 +1343,7 @@ func Compile(gram *Grammar, opts ...CompileOption) (*spec.CompiledGrammar, *spec StartProduction: productionNumStart.Int(), LHSSymbols: lhsSyms, AlternativeSymbolCounts: altSymCounts, - Terminals: terms, + Terminals: termTexts, TerminalCount: tab.terminalCount, NonTerminals: nonTerms, NonTerminalCount: tab.nonTerminalCount, |