Define a lexical specification interface

1 files changed, 73 insertions, 0 deletions

diff --git a/driver/spec.go b/driver/spec.go
new file mode 100644
index 0000000..149d922
--- /dev/null
+++ b/driver/spec.go
@@ -0,0 +1,73 @@
+package driver
+
+import (
+	"github.com/nihei9/maleeni/spec"
+)
+
+type lexSpec struct {
+	spec *spec.CompiledLexSpec
+}
+
+func NewLexSpec(spec *spec.CompiledLexSpec) *lexSpec {
+	return &lexSpec{
+		spec: spec,
+	}
+}
+
+func (s *lexSpec) InitialMode() ModeID {
+	return ModeID(s.spec.InitialModeID.Int())
+}
+
+func (s *lexSpec) Pop(mode ModeID, modeKind ModeKindID) bool {
+	return s.spec.Specs[mode].Pop[modeKind] == 1
+}
+
+func (s *lexSpec) Push(mode ModeID, modeKind ModeKindID) (ModeID, bool) {
+	modeID := s.spec.Specs[mode].Push[modeKind]
+	return ModeID(modeID.Int()), !modeID.IsNil()
+}
+
+func (s *lexSpec) ModeName(mode ModeID) string {
+	return s.spec.ModeNames[mode].String()
+}
+
+func (s *lexSpec) InitialState(mode ModeID) StateID {
+	return StateID(s.spec.Specs[mode].DFA.InitialStateID.Int())
+}
+
+func (s *lexSpec) NextState(mode ModeID, state StateID, v int) (StateID, bool) {
+	switch s.spec.CompressionLevel {
+	case 2:
+		tran := s.spec.Specs[mode].DFA.Transition
+		rowNum := tran.RowNums[state]
+		d := tran.UniqueEntries.RowDisplacement[rowNum]
+		if tran.UniqueEntries.Bounds[d+v] != rowNum {
+			return StateID(tran.UniqueEntries.EmptyValue.Int()), false
+		}
+		return StateID(tran.UniqueEntries.Entries[d+v].Int()), true
+	case 1:
+		tran := s.spec.Specs[mode].DFA.Transition
+		next := tran.UncompressedUniqueEntries[tran.RowNums[state]*tran.OriginalColCount+v]
+		if next == spec.StateIDNil {
+			return StateID(spec.StateIDNil.Int()), false
+		}
+		return StateID(next.Int()), true
+	}
+
+	modeSpec := s.spec.Specs[mode]
+	next := modeSpec.DFA.UncompressedTransition[state.Int()*modeSpec.DFA.ColCount+v]
+	if next == spec.StateIDNil {
+		return StateID(spec.StateIDNil), false
+	}
+	return StateID(next.Int()), true
+}
+
+func (s *lexSpec) Accept(mode ModeID, state StateID) (ModeKindID, bool) {
+	modeKindID := s.spec.Specs[mode].DFA.AcceptingStates[state]
+	return ModeKindID(modeKindID.Int()), modeKindID != spec.LexModeKindIDNil
+}
+
+func (s *lexSpec) KindIDAndName(mode ModeID, modeKind ModeKindID) (KindID, string) {
+	kindID := s.spec.KindIDs[mode][modeKind]
+	return KindID(kindID.Int()), s.spec.KindNames[kindID].String()
+}