diff options
Diffstat (limited to 'grammar/slr_test.go')
| -rw-r--r-- | grammar/slr_test.go | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/grammar/slr_test.go b/grammar/slr_test.go new file mode 100644 index 0000000..089b73b --- /dev/null +++ b/grammar/slr_test.go @@ -0,0 +1,481 @@ +package grammar + +import ( + "fmt" + "strings" + "testing" + + "github.com/nihei9/vartan/spec" +) + +func TestGenSLRParsingTable(t *testing.T) { + src := ` +expr + : expr add term + | term + ; +term + : term mul factor + | factor + ; +factor + : l_paren expr r_paren + | id + ; +add: "\+"; +mul: "\*"; +l_paren: "\("; +r_paren: "\)"; +id: "[A-Za-z_][0-9A-Za-z_]*"; +` + + var ptab *ParsingTable + var automaton *lr0Automaton + var gram *Grammar + var nonTermCount int + var termCount int + { + ast, err := spec.Parse(strings.NewReader(src)) + if err != nil { + t.Fatal(err) + } + gram, err = NewGrammar(ast) + if err != nil { + t.Fatal(err) + } + first, err := genFirstSet(gram.productionSet) + if err != nil { + t.Fatal(err) + } + follow, err := genFollowSet(gram.productionSet, first) + if err != nil { + t.Fatal(err) + } + automaton, err = genLR0Automaton(gram.productionSet, gram.augmentedStartSymbol) + if err != nil { + t.Fatal(err) + } + + nonTermTexts, err := gram.symbolTable.getNonTerminalTexts() + if err != nil { + t.Fatal(err) + } + termTexts, err := gram.symbolTable.getTerminalTexts() + if err != nil { + t.Fatal(err) + } + nonTermCount = len(nonTermTexts) + termCount = len(termTexts) + + ptab, err = genSLRParsingTable(automaton, gram.productionSet, follow, termCount, nonTermCount) + if err != nil { + t.Fatalf("failed to create a SLR parsing table: %v", err) + } + if ptab == nil { + t.Fatal("genSLRParsingTable returns nil without any error") + } + } + + genSym := newTestSymbolGenerator(t, gram.symbolTable) + genProd := newTestProductionGenerator(t, genSym) + genLR0Item := newTestLR0ItemGenerator(t, genProd) + + expectedKernels := map[int][]*lr0Item{ + 0: { + genLR0Item("expr'", 0, "expr"), + }, + 1: { + genLR0Item("expr'", 1, "expr"), + genLR0Item("expr", 1, "expr", "add", "term"), + }, + 2: { + genLR0Item("expr", 1, "term"), + genLR0Item("term", 1, "term", "mul", "factor"), + }, + 3: { + genLR0Item("term", 1, "factor"), + }, + 4: { + genLR0Item("factor", 1, "l_paren", "expr", "r_paren"), + }, + 5: { + genLR0Item("factor", 1, "id"), + }, + 6: { + genLR0Item("expr", 2, "expr", "add", "term"), + }, + 7: { + genLR0Item("term", 2, "term", "mul", "factor"), + }, + 8: { + genLR0Item("expr", 1, "expr", "add", "term"), + genLR0Item("factor", 2, "l_paren", "expr", "r_paren"), + }, + 9: { + genLR0Item("expr", 3, "expr", "add", "term"), + genLR0Item("term", 1, "term", "mul", "factor"), + }, + 10: { + genLR0Item("term", 3, "term", "mul", "factor"), + }, + 11: { + genLR0Item("factor", 3, "l_paren", "expr", "r_paren"), + }, + } + + expectedStates := []struct { + kernelItems []*lr0Item + acts map[symbol]testActionEntry + goTos map[symbol][]*lr0Item + }{ + { + kernelItems: expectedKernels[0], + acts: map[symbol]testActionEntry{ + genSym("l_paren"): { + ty: ActionTypeShift, + nextState: expectedKernels[4], + }, + genSym("id"): { + ty: ActionTypeShift, + nextState: expectedKernels[5], + }, + }, + goTos: map[symbol][]*lr0Item{ + genSym("expr"): expectedKernels[1], + genSym("term"): expectedKernels[2], + genSym("factor"): expectedKernels[3], + }, + }, + { + kernelItems: expectedKernels[1], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeShift, + nextState: expectedKernels[6], + }, + symbolEOF: { + ty: ActionTypeReduce, + production: genProd("expr'", "expr"), + }, + }, + }, + { + kernelItems: expectedKernels[2], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeReduce, + production: genProd("expr", "term"), + }, + genSym("mul"): { + ty: ActionTypeShift, + nextState: expectedKernels[7], + }, + genSym("r_paren"): { + ty: ActionTypeReduce, + production: genProd("expr", "term"), + }, + symbolEOF: { + ty: ActionTypeReduce, + production: genProd("expr", "term"), + }, + }, + }, + { + kernelItems: expectedKernels[3], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeReduce, + production: genProd("term", "factor"), + }, + genSym("mul"): { + ty: ActionTypeReduce, + production: genProd("term", "factor"), + }, + genSym("r_paren"): { + ty: ActionTypeReduce, + production: genProd("term", "factor"), + }, + symbolEOF: { + ty: ActionTypeReduce, + production: genProd("term", "factor"), + }, + }, + }, + { + kernelItems: expectedKernels[4], + acts: map[symbol]testActionEntry{ + genSym("l_paren"): { + ty: ActionTypeShift, + nextState: expectedKernels[4], + }, + genSym("id"): { + ty: ActionTypeShift, + nextState: expectedKernels[5], + }, + }, + goTos: map[symbol][]*lr0Item{ + genSym("expr"): expectedKernels[8], + genSym("term"): expectedKernels[2], + genSym("factor"): expectedKernels[3], + }, + }, + { + kernelItems: expectedKernels[5], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeReduce, + production: genProd("factor", "id"), + }, + genSym("mul"): { + ty: ActionTypeReduce, + production: genProd("factor", "id"), + }, + genSym("r_paren"): { + ty: ActionTypeReduce, + production: genProd("factor", "id"), + }, + symbolEOF: { + ty: ActionTypeReduce, + production: genProd("factor", "id"), + }, + }, + }, + { + kernelItems: expectedKernels[6], + acts: map[symbol]testActionEntry{ + genSym("l_paren"): { + ty: ActionTypeShift, + nextState: expectedKernels[4], + }, + genSym("id"): { + ty: ActionTypeShift, + nextState: expectedKernels[5], + }, + }, + goTos: map[symbol][]*lr0Item{ + genSym("term"): expectedKernels[9], + genSym("factor"): expectedKernels[3], + }, + }, + { + kernelItems: expectedKernels[7], + acts: map[symbol]testActionEntry{ + genSym("l_paren"): { + ty: ActionTypeShift, + nextState: expectedKernels[4], + }, + genSym("id"): { + ty: ActionTypeShift, + nextState: expectedKernels[5], + }, + }, + goTos: map[symbol][]*lr0Item{ + genSym("factor"): expectedKernels[10], + }, + }, + { + kernelItems: expectedKernels[8], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeShift, + nextState: expectedKernels[6], + }, + genSym("r_paren"): { + ty: ActionTypeShift, + nextState: expectedKernels[11], + }, + }, + }, + { + kernelItems: expectedKernels[9], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeReduce, + production: genProd("expr", "expr", "add", "term"), + }, + genSym("mul"): { + ty: ActionTypeShift, + nextState: expectedKernels[7], + }, + genSym("r_paren"): { + ty: ActionTypeReduce, + production: genProd("expr", "expr", "add", "term"), + }, + symbolEOF: { + ty: ActionTypeReduce, + production: genProd("expr", "expr", "add", "term"), + }, + }, + }, + { + kernelItems: expectedKernels[10], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeReduce, + production: genProd("term", "term", "mul", "factor"), + }, + genSym("mul"): { + ty: ActionTypeReduce, + production: genProd("term", "term", "mul", "factor"), + }, + genSym("r_paren"): { + ty: ActionTypeReduce, + production: genProd("term", "term", "mul", "factor"), + }, + symbolEOF: { + ty: ActionTypeReduce, + production: genProd("term", "term", "mul", "factor"), + }, + }, + }, + { + kernelItems: expectedKernels[11], + acts: map[symbol]testActionEntry{ + genSym("add"): { + ty: ActionTypeReduce, + production: genProd("factor", "l_paren", "expr", "r_paren"), + }, + genSym("mul"): { + ty: ActionTypeReduce, + production: genProd("factor", "l_paren", "expr", "r_paren"), + }, + genSym("r_paren"): { + ty: ActionTypeReduce, + production: genProd("factor", "l_paren", "expr", "r_paren"), + }, + symbolEOF: { + ty: ActionTypeReduce, + production: genProd("factor", "l_paren", "expr", "r_paren"), + }, + }, + }, + } + + t.Run("initial state", func(t *testing.T) { + iniState := findStateByNum(automaton.states, ptab.InitialState) + if iniState == nil { + t.Fatalf("the initial state was not found: #%v", ptab.InitialState) + } + eIniState, err := newKernel(expectedKernels[0]) + if err != nil { + t.Fatalf("failed to create a kernel item: %v", err) + } + if iniState.id != eIniState.id { + t.Fatalf("the initial state is mismatched; want: %v, got: %v", eIniState.id, iniState.id) + } + }) + + for i, eState := range expectedStates { + t.Run(fmt.Sprintf("#%v", i), func(t *testing.T) { + k, err := newKernel(eState.kernelItems) + if err != nil { + t.Fatalf("failed to create a kernel item: %v", err) + } + state, ok := automaton.states[k.id] + if !ok { + t.Fatalf("state was not found: #%v", 0) + } + + // ACTION + { + nonEmptyEntries := map[symbolNum]struct{}{} + for eSym, eAct := range eState.acts { + nonEmptyEntries[eSym.num()] = struct{}{} + + ty, stateNum, prodNum := ptab.getAction(state.num, eSym.num()) + if ty != eAct.ty { + t.Fatalf("action type is mismatched; want: %v, got: %v", eAct.ty, ty) + } + switch eAct.ty { + case ActionTypeShift: + eNextState, err := newKernel(eAct.nextState) + if err != nil { + t.Fatal(err) + } + nextState := findStateByNum(automaton.states, stateNum) + if nextState == nil { + t.Fatalf("state was not found; state: #%v", stateNum) + } + if nextState.id != eNextState.id { + t.Fatalf("next state is mismatched; symbol: %v, want: %v, got: %v", eSym, eNextState.id, nextState.id) + } + case ActionTypeReduce: + prod := findProductionByNum(gram.productionSet, prodNum) + if prod == nil { + t.Fatalf("production was not found: #%v", prodNum) + } + if prod.id != eAct.production.id { + t.Fatalf("production is mismatched; symbol: %v, want: %v, got: %v", eSym, eAct.production.id, prod.id) + } + } + } + for symNum := 0; symNum < termCount; symNum++ { + if _, checked := nonEmptyEntries[symbolNum(symNum)]; checked { + continue + } + ty, stateNum, prodNum := ptab.getAction(state.num, symbolNum(symNum)) + if ty != ActionTypeError { + t.Errorf("unexpected ACTION entry; state: #%v, symbol: #%v, action type: %v, next state: #%v, prodction: #%v", state.num, symNum, ty, stateNum, prodNum) + } + } + } + + // GOTO + { + nonEmptyEntries := map[symbolNum]struct{}{} + for eSym, eGoTo := range eState.goTos { + nonEmptyEntries[eSym.num()] = struct{}{} + + eNextState, err := newKernel(eGoTo) + if err != nil { + t.Fatal(err) + } + ty, stateNum := ptab.getGoTo(state.num, eSym.num()) + if ty != GoToTypeRegistered { + t.Fatalf("GOTO entry was not found; state: #%v, symbol: #%v", state.num, eSym) + } + nextState := findStateByNum(automaton.states, stateNum) + if nextState == nil { + t.Fatalf("state was not found: #%v", stateNum) + } + if nextState.id != eNextState.id { + t.Fatalf("next state is mismatched; symbol: %v, want: %v, got: %v", eSym, eNextState.id, nextState.id) + } + } + for symNum := 0; symNum < nonTermCount; symNum++ { + if _, checked := nonEmptyEntries[symbolNum(symNum)]; checked { + continue + } + ty, _ := ptab.getGoTo(state.num, symbolNum(symNum)) + if ty != GoToTypeError { + t.Errorf("unexpected GOTO entry; state: #%v, symbol: #%v", state.num, symNum) + } + } + } + }) + } +} + +type testActionEntry struct { + ty ActionType + nextState []*lr0Item + production *production +} + +func findStateByNum(states map[kernelID]*lr0State, num stateNum) *lr0State { + for _, state := range states { + if state.num == num { + return state + } + } + return nil +} + +func findProductionByNum(prods *productionSet, num productionNum) *production { + for _, prod := range prods.getAllProductions() { + if prod.num == num { + return prod + } + } + return nil +} |