Exemplo n.º 1
0
func writeTerminals(gSymbols *symbols.Symbols, cfg config.Config) {
	buf := new(bytes.Buffer)
	for _, t := range gSymbols.ListTerminals() {
		fmt.Fprintf(buf, "%s\n", t)
	}
	io.WriteFile(path.Join(cfg.OutDir(), "terminals.txt"), buf.Bytes())
}
Exemplo n.º 2
0
// TODO: optimise loop
// g is a BNF grammar. Items returns the sets of Items of the grammar g.
func GetItemSets(g *ast.Grammar, s *symbols.Symbols, firstSets *first.FirstSets) *ItemSets {
	C := &ItemSets{
		sets: []*ItemSet{InitialItemSet(g, s, firstSets).Closure()},
	}
	symbols := s.List()
	included := -1
	for again := true; again; {
		again = false
		for i, I := range C.sets {
			if i > included {
				for _, X := range symbols {
					gto := I.Goto(X)
					if gto.Size() > 0 {
						idx := C.GetIndex(gto)
						if idx == -1 {
							C.sets, again = append(C.sets, gto), true
							idx = len(C.sets) - 1
							gto.SetNo = idx
						}
						I.AddTransition(X, idx)
					}
				}
				included = i
			}
		}
	}
	return C
}
Exemplo n.º 3
0
func getGotoRowData(itemSet *items.ItemSet, sym *symbols.Symbols) []gotoRowElement {
	row := make([]gotoRowElement, sym.NumNTSymbols())
	for i, nt := range sym.NTList() {
		row[i].NT = nt
		row[i].State = itemSet.NextSetIndex(nt)
	}
	return row
}
Exemplo n.º 4
0
func getGotoTableData(itemSets *items.ItemSets, sym *symbols.Symbols) *gotoTableData {
	data := &gotoTableData{
		NumNTSymbols: sym.NumNTSymbols(),
		Rows:         make([]string, itemSets.Size()),
	}
	for i, set := range itemSets.List() {
		data.Rows[i] = genGotoRow(set, sym)
	}
	return data
}
Exemplo n.º 5
0
func getProdsTab(header string, prods ast.SyntaxProdList, symbols *symbols.Symbols,
	itemsets *items.ItemSets, tokMap *token.TokenMap) *prodsTabData {

	data := &prodsTabData{
		Header:  header,
		ProdTab: make([]prodTabEntry, len(prods)),
	}
	for i, prod := range prods {
		data.ProdTab[i].String = fmt.Sprintf("`%s`", prod.String())
		data.ProdTab[i].Id = prod.Id
		data.ProdTab[i].NTType = symbols.NTType(prod.Id)
		if prod.Body.Symbols[0].SymbolString() == "empty" {
			data.ProdTab[i].NumSymbols = 0
			data.ProdTab[i].ReduceFunc = fmt.Sprintf("return nil, nil")
		} else {
			data.ProdTab[i].NumSymbols = len(prod.Body.Symbols)
			switch {
			case prod.Body.SDT != "":
				data.ProdTab[i].ReduceFunc = fmt.Sprintf("return %s", prod.Body.SDT)
			default:
				data.ProdTab[i].ReduceFunc = fmt.Sprintf("return X[0], nil")
			}
		}
	}

	return data
}
Exemplo n.º 6
0
//Returns the FirstSets of the Grammar.
func GetFirstSets(g *ast.Grammar, symbols *symbols.Symbols) *FirstSets {
	firstSets := &FirstSets{
		firstSets: make(map[string]SymbolSet),
		symbols:   symbols,
	}

	if g.SyntaxPart == nil {
		return firstSets
	}

	for i, again := 1, true; again; i++ {
		again = false
		for _, prod := range g.SyntaxPart.ProdList {
			switch {
			case len(prod.Body.Symbols) == 0:
				if firstSets.AddToken(prod.Id, EMPTY) {
					again = true
				}
			case symbols.IsTerminal(prod.Body.Symbols[0].SymbolString()):
				if firstSets.AddToken(prod.Id, prod.Body.Symbols[0].SymbolString()) {
					again = true
				}
			default:
				first := FirstS(firstSets, stringList(prod.Body.Symbols))
				if !first.Equal(firstSets.GetSet(prod.Id)) {
					if firstSets.AddSet(prod.Id, first) {
						again = true
					}
				}
			}
		}
	}

	return firstSets
}
Exemplo n.º 7
0
func getParserData(pkg string, prods ast.SyntaxProdList, itemSets *items.ItemSets, symbols *symbols.Symbols, cfg config.Config) *parserData {
	return &parserData{
		Debug:          cfg.DebugParser(),
		ErrorImport:    path.Join(pkg, "errors"),
		TokenImport:    path.Join(pkg, "token"),
		NumProductions: len(prods),
		NumStates:      itemSets.Size(),
		NumSymbols:     symbols.NumSymbols(),
	}
}