diff options
Diffstat (limited to 'grammar/lalr1.go')
| -rw-r--r-- | grammar/lalr1.go | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/grammar/lalr1.go b/grammar/lalr1.go index f1b8149..1667d84 100644 --- a/grammar/lalr1.go +++ b/grammar/lalr1.go @@ -1,6 +1,10 @@ package grammar -import "fmt" +import ( + "fmt" + + "github.com/nihei9/vartan/grammar/symbol" +) type stateAndLRItem struct { kernelID kernelID @@ -19,8 +23,8 @@ type lalr1Automaton struct { func genLALR1Automaton(lr0 *lr0Automaton, prods *productionSet, first *firstSet) (*lalr1Automaton, error) { // Set the look-ahead symbol <EOF> to the initial item: [S' → ・S, $] iniState := lr0.states[lr0.initialState] - iniState.items[0].lookAhead.symbols = map[symbol]struct{}{ - symbolEOF: {}, + iniState.items[0].lookAhead.symbols = map[symbol.Symbol]struct{}{ + symbol.SymbolEOF: {}, } var props []*propagation @@ -55,7 +59,7 @@ func genLALR1Automaton(lr0 *lr0Automaton, prods *productionSet, first *firstSet) return nil, fmt.Errorf("reducible item not found: %v", item.id) } if reducibleItem.lookAhead.symbols == nil { - reducibleItem.lookAhead.symbols = map[symbol]struct{}{} + reducibleItem.lookAhead.symbols = map[symbol.Symbol]struct{}{} } for a := range item.lookAhead.symbols { reducibleItem.lookAhead.symbols[a] = struct{}{} @@ -104,7 +108,7 @@ func genLALR1Automaton(lr0 *lr0Automaton, prods *productionSet, first *firstSet) } if nextItem.lookAhead.symbols == nil { - nextItem.lookAhead.symbols = map[symbol]struct{}{} + nextItem.lookAhead.symbols = map[symbol.Symbol]struct{}{} } for a := range item.lookAhead.symbols { @@ -138,7 +142,7 @@ func genLALR1Automaton(lr0 *lr0Automaton, prods *productionSet, first *firstSet) func genLALR1Closure(srcItem *lrItem, prods *productionSet, first *firstSet) ([]*lrItem, error) { items := []*lrItem{} - knownItems := map[lrItemID]map[symbol]struct{}{} + knownItems := map[lrItemID]map[symbol.Symbol]struct{}{} knownItemsProp := map[lrItemID]struct{}{} uncheckedItems := []*lrItem{} items = append(items, srcItem) @@ -146,7 +150,7 @@ func genLALR1Closure(srcItem *lrItem, prods *productionSet, first *firstSet) ([] for len(uncheckedItems) > 0 { nextUncheckedItems := []*lrItem{} for _, item := range uncheckedItems { - if item.dottedSymbol.isTerminal() { + if item.dottedSymbol.IsTerminal() { continue } @@ -155,7 +159,7 @@ func genLALR1Closure(srcItem *lrItem, prods *productionSet, first *firstSet) ([] return nil, fmt.Errorf("production not found: %v", item.prod) } - var fstSyms []symbol + var fstSyms []symbol.Symbol var isFstNullable bool { fst, err := first.find(p, item.dot+1) @@ -163,7 +167,7 @@ func genLALR1Closure(srcItem *lrItem, prods *productionSet, first *firstSet) ([] return nil, err } - fstSyms = make([]symbol, len(fst.symbols)) + fstSyms = make([]symbol.Symbol, len(fst.symbols)) i := 0 for s := range fst.symbols { fstSyms[i] = s @@ -176,7 +180,7 @@ func genLALR1Closure(srcItem *lrItem, prods *productionSet, first *firstSet) ([] ps, _ := prods.findByLHS(item.dottedSymbol) for _, prod := range ps { - var lookAhead []symbol + var lookAhead []symbol.Symbol { var lookAheadCount int if isFstNullable { @@ -185,7 +189,7 @@ func genLALR1Closure(srcItem *lrItem, prods *productionSet, first *firstSet) ([] lookAheadCount = len(fstSyms) } - lookAhead = make([]symbol, lookAheadCount) + lookAhead = make([]symbol.Symbol, lookAheadCount) i := 0 for _, s := range fstSyms { lookAhead[i] = s @@ -210,13 +214,13 @@ func genLALR1Closure(srcItem *lrItem, prods *productionSet, first *firstSet) ([] } } - newItem.lookAhead.symbols = map[symbol]struct{}{ + newItem.lookAhead.symbols = map[symbol.Symbol]struct{}{ a: {}, } items = append(items, newItem) if knownItems[newItem.id] == nil { - knownItems[newItem.id] = map[symbol]struct{}{} + knownItems[newItem.id] = map[symbol.Symbol]struct{}{} } knownItems[newItem.id][a] = struct{}{} nextUncheckedItems = append(nextUncheckedItems, newItem) @@ -297,7 +301,7 @@ func propagateLookAhead(lr0 *lr0Automaton, props []*propagation) error { } if destItem.lookAhead.symbols == nil { - destItem.lookAhead.symbols = map[symbol]struct{}{} + destItem.lookAhead.symbols = map[symbol.Symbol]struct{}{} } destItem.lookAhead.symbols[a] = struct{}{} |