diff options
Diffstat (limited to 'grammar/grammar.go')
| -rw-r--r-- | grammar/grammar.go | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/grammar/grammar.go b/grammar/grammar.go index 3344b64..b9f65dc 100644 --- a/grammar/grammar.go +++ b/grammar/grammar.go @@ -42,11 +42,14 @@ func NewGrammar(root *spec.RootNode) (*Grammar, error) { dir := prod.Directive switch dir.Name { case "mode": - if dir.Parameter == nil || dir.Parameter.ID == "" { + if len(dir.Parameters) == 0 { return nil, fmt.Errorf("'mode' directive needs an ID parameter") } - modes = []mlspec.LexModeName{ - mlspec.LexModeName(dir.Parameter.ID), + for _, param := range dir.Parameters { + if param.ID == "" { + return nil, fmt.Errorf("'mode' directive needs an ID parameter") + } + modes = append(modes, mlspec.LexModeName(param.ID)) } default: return nil, fmt.Errorf("invalid directive name '%v'", dir.Name) @@ -60,20 +63,17 @@ func NewGrammar(root *spec.RootNode) (*Grammar, error) { dir := alt.Directive switch dir.Name { case "skip": - param := dir.Parameter - if param != nil { + if len(dir.Parameters) > 0 { return nil, fmt.Errorf("'skip' directive needs no parameter") } skip = append(skip, mlspec.LexKind(prod.LHS)) case "push": - param := dir.Parameter - if param == nil || param.ID == "" { + if len(dir.Parameters) != 1 || dir.Parameters[0].ID == "" { return nil, fmt.Errorf("'push' directive needs an ID parameter") } - push = mlspec.LexModeName(param.ID) + push = mlspec.LexModeName(dir.Parameters[0].ID) case "pop": - param := dir.Parameter - if param != nil { + if len(dir.Parameters) > 0 { return nil, fmt.Errorf("'pop' directive needs no parameter") } pop = true @@ -214,10 +214,10 @@ func NewGrammar(root *spec.RootNode) (*Grammar, error) { dir := alt.Directive switch dir.Name { case "ast": - param := dir.Parameter - if param == nil || param.Tree == nil { + if len(dir.Parameters) != 1 || dir.Parameters[0].Tree == nil { return nil, fmt.Errorf("'ast' directive needs a tree parameter") } + param := dir.Parameters[0] lhsText, ok := symTab.toText(p.lhs) if !ok || param.Tree.Name != lhsText { return nil, fmt.Errorf("a name of a tree structure must be the same ID as an LHS of a production; LHS: %v", lhsText) |