diff options
Diffstat (limited to 'grammar/grammar.go')
| -rw-r--r-- | grammar/grammar.go | 59 |
1 files changed, 29 insertions, 30 deletions
diff --git a/grammar/grammar.go b/grammar/grammar.go index 7dbd0ed..9d1933b 100644 --- a/grammar/grammar.go +++ b/grammar/grammar.go @@ -759,69 +759,68 @@ func (b *GrammarBuilder) genProductionsAndActions(root *spec.RootNode, symTabAnd dir := alt.Directive switch dir.Name { case "ast": - if len(dir.Parameters) != 1 || dir.Parameters[0].Tree == nil { + if len(dir.Parameters) == 0 { b.errs = append(b.errs, &verr.SpecError{ Cause: semErrDirInvalidParam, - Detail: "'ast' directive needs a tree parameter", + Detail: "'ast' directive needs at least one symbol position parameter", Row: dir.Pos.Row, Col: dir.Pos.Col, }) continue LOOP_RHS } - param := dir.Parameters[0] - lhsText, ok := symTab.toText(p.lhs) - if !ok || param.Tree.Name != lhsText { - b.errs = append(b.errs, &verr.SpecError{ - Cause: semErrDirInvalidParam, - Detail: fmt.Sprintf("a name of a tree structure must be the same ID as an LHS of a production; LHS: %v", lhsText), - Row: param.Pos.Row, - Col: param.Pos.Col, - }) - continue LOOP_RHS - } - astAct := make([]*astActionEntry, len(param.Tree.Children)) - for i, c := range param.Tree.Children { - if c.Position > len(alt.Elements) { + astAct := make([]*astActionEntry, len(dir.Parameters)) + for i, param := range dir.Parameters { + if param.SymbolPosition == nil { + b.errs = append(b.errs, &verr.SpecError{ + Cause: semErrDirInvalidParam, + Detail: "'ast' directive can take only symbol position parameters", + Row: dir.Pos.Row, + Col: dir.Pos.Col, + }) + continue LOOP_RHS + } + symPos := param.SymbolPosition + if symPos.Position > len(alt.Elements) { b.errs = append(b.errs, &verr.SpecError{ Cause: semErrDirInvalidParam, - Detail: fmt.Sprintf("a position must be less than or equal to the length of an alternativ (%v)", len(alt.Elements)), - Row: c.Pos.Row, - Col: c.Pos.Col, + Detail: fmt.Sprintf("a symbol position must be less than or equal to the length of an alternativ (%v)", len(alt.Elements)), + Row: symPos.Pos.Row, + Col: symPos.Pos.Col, }) continue LOOP_RHS } - if c.Expansion { - offset := c.Position - 1 + if symPos.Expansion { + offset := symPos.Position - 1 elem := alt.Elements[offset] if elem.Pattern != "" { b.errs = append(b.errs, &verr.SpecError{ Cause: semErrDirInvalidParam, - Detail: fmt.Sprintf("the expansion symbol cannot be applied to a pattern ($%v: %v)", c.Position, elem.Pattern), - Row: c.Pos.Row, - Col: c.Pos.Col, + Detail: fmt.Sprintf("the expansion symbol cannot be applied to a pattern ($%v: %v)", symPos.Position, elem.Pattern), + Row: symPos.Pos.Row, + Col: symPos.Pos.Col, }) continue LOOP_RHS } elemSym, ok := symTab.toSymbol(elem.ID) if !ok { // If the symbol was not found, it's a bug. - return nil, fmt.Errorf("a symbol corresponding to a position ($%v: %v) was not found", c.Position, elem.ID) + return nil, fmt.Errorf("a symbol corresponding to a position ($%v: %v) was not found", symPos.Position, elem.ID) } if elemSym.isTerminal() { b.errs = append(b.errs, &verr.SpecError{ Cause: semErrDirInvalidParam, - Detail: fmt.Sprintf("the expansion symbol cannot be applied to a terminal symbol ($%v: %v)", c.Position, elem.ID), - Row: c.Pos.Row, - Col: c.Pos.Col, + Detail: fmt.Sprintf("the expansion symbol cannot be applied to a terminal symbol ($%v: %v)", symPos.Position, elem.ID), + Row: symPos.Pos.Row, + Col: symPos.Pos.Col, }) continue LOOP_RHS } } astAct[i] = &astActionEntry{ - position: c.Position, - expansion: c.Expansion, + position: symPos.Position, + expansion: symPos.Expansion, } } astActs[p.id] = astAct |