1 files changed, 104 insertions, 0 deletions
diff --git a/compiler/dfa_test.go b/compiler/dfa_test.go
new file mode 100644
index 0000000..26ee189
--- /dev/null
+++ b/compiler/dfa_test.go
@@ -0,0 +1,104 @@
+package compiler
+
+import (
+	"testing"
+)
+
+func TestGenDFA(t *testing.T) {
+	root, symTab, err := parse(map[int][]byte{
+		1: []byte("(a|b)*abb"),
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	dfa := genDFA(root, symTab)
+	if dfa == nil {
+		t.Fatalf("DFA is nil")
+	}
+
+	symPos := func(n uint8) symbolPosition {
+		return newSymbolPosition(n, false)
+	}
+
+	endPos := func(n uint8) symbolPosition {
+		return newSymbolPosition(n, true)
+	}
+
+	s0 := newSymbolPositionSet().add(symPos(1)).add(symPos(2)).add(symPos(3))
+	s1 := newSymbolPositionSet().add(symPos(1)).add(symPos(2)).add(symPos(3)).add(symPos(4))
+	s2 := newSymbolPositionSet().add(symPos(1)).add(symPos(2)).add(symPos(3)).add(symPos(5))
+	s3 := newSymbolPositionSet().add(symPos(1)).add(symPos(2)).add(symPos(3)).add(endPos(6))
+
+	rune2Int := func(char rune, index int) uint8 {
+		return uint8([]byte(string(char))[index])
+	}
+
+	tranS0 := [256]string{}
+	tranS0[rune2Int('a', 0)] = s1.hash()
+	tranS0[rune2Int('b', 0)] = s0.hash()
+
+	tranS1 := [256]string{}
+	tranS1[rune2Int('a', 0)] = s1.hash()
+	tranS1[rune2Int('b', 0)] = s2.hash()
+
+	tranS2 := [256]string{}
+	tranS2[rune2Int('a', 0)] = s1.hash()
+	tranS2[rune2Int('b', 0)] = s3.hash()
+
+	tranS3 := [256]string{}
+	tranS3[rune2Int('a', 0)] = s1.hash()
+	tranS3[rune2Int('b', 0)] = s0.hash()
+
+	expectedTranTab := map[string][256]string{
+		s0.hash(): tranS0,
+		s1.hash(): tranS1,
+		s2.hash(): tranS2,
+		s3.hash(): tranS3,
+	}
+	if len(dfa.TransitionTable) != len(expectedTranTab) {
+		t.Errorf("transition table is mismatched; want: %v entries, got: %v entries", len(expectedTranTab), len(dfa.TransitionTable))
+	}
+	for h, eTranTab := range expectedTranTab {
+		tranTab, ok := dfa.TransitionTable[h]
+		if !ok {
+			t.Errorf("no entry; hash: %v", h)
+			continue
+		}
+		if len(tranTab) != len(eTranTab) {
+			t.Errorf("transition table is mismatched; hash: %v, want: %v entries, got: %v entries", h, len(eTranTab), len(tranTab))
+		}
+		for c, eNext := range eTranTab {
+			if eNext == "" {
+				continue
+			}
+
+			next := tranTab[c]
+			if next == "" {
+				t.Errorf("no enatry; hash: %v, char: %v", h, c)
+			}
+			if next != eNext {
+				t.Errorf("next state is mismatched; want: %v, got: %v", eNext, next)
+			}
+		}
+	}
+
+	if dfa.InitialState != s0.hash() {
+		t.Errorf("initial state is mismatched; want: %v, got: %v", s0.hash(), dfa.InitialState)
+	}
+
+	accTab := map[string]int{
+		s3.hash(): 1,
+	}
+	if len(dfa.AcceptingStatesTable) != len(accTab) {
+		t.Errorf("accepting states are mismatched; want: %v entries, got: %v entries", len(accTab), len(dfa.AcceptingStatesTable))
+	}
+	for eState, eID := range accTab {
+		id, ok := dfa.AcceptingStatesTable[eState]
+		if !ok {
+			t.Errorf("accepting state is not found; state: %v", eState)
+		}
+		if id != eID {
+			t.Errorf("ID is mismatched; state: %v, want: %v, got: %v", eState, eID, id)
+		}
+	}
+}