diff options
Diffstat (limited to 'src/urubu/driver/parser')
-rw-r--r-- | src/urubu/driver/parser/parser.go | 416 | ||||
-rw-r--r-- | src/urubu/driver/parser/semantic_action.go | 371 | ||||
-rw-r--r-- | src/urubu/driver/parser/spec.go | 73 | ||||
-rw-r--r-- | src/urubu/driver/parser/template.go | 535 | ||||
-rw-r--r-- | src/urubu/driver/parser/token_stream.go | 65 |
5 files changed, 0 insertions, 1460 deletions
diff --git a/src/urubu/driver/parser/parser.go b/src/urubu/driver/parser/parser.go deleted file mode 100644 index 2eaa678..0000000 --- a/src/urubu/driver/parser/parser.go +++ /dev/null @@ -1,416 +0,0 @@ -package parser - -import ( - "fmt" -) - -type Grammar interface { - // InitialState returns the initial state of a parser. - InitialState() int - - // StartProduction returns the start production of grammar. - StartProduction() int - - // Action returns an ACTION entry corresponding to a (state, terminal symbol) pair. - Action(state int, terminal int) int - - // GoTo returns a GOTO entry corresponding to a (state, non-terminal symbol) pair. - GoTo(state int, lhs int) int - - // ErrorTrapperState returns true when a state can shift the error symbol. - ErrorTrapperState(state int) bool - - // LHS returns a LHS symbol of a production. - LHS(prod int) int - - // AlternativeSymbolCount returns a symbol count of p production. - AlternativeSymbolCount(prod int) int - - // RecoverProduction returns true when a production has the recover directive. - RecoverProduction(prod int) bool - - // NonTerminal retuns a string representaion of a non-terminal symbol. - NonTerminal(nonTerminal int) string - - // TerminalCount returns a terminal symbol count of grammar. - TerminalCount() int - - // SkipTerminal returns true when a terminal symbol must be skipped on syntax analysis. - SkipTerminal(terminal int) bool - - // EOF returns the EOF symbol. - EOF() int - - // Error returns the error symbol. - Error() int - - // Terminal retuns a string representaion of a terminal symbol. - Terminal(terminal int) string - - // ASTAction returns an AST action entries. - ASTAction(prod int) []int -} - -type VToken interface { - // TerminalID returns a terminal ID. - TerminalID() int - - // Lexeme returns a lexeme. - Lexeme() []byte - - // EOF returns true when a token represents EOF. - EOF() bool - - // Invalid returns true when a token is invalid. - Invalid() bool - - // BytePosition returns (position, length) pair. - // `position` is a byte position where a token appears and `length` is a length in bytes. - BytePosition() (int, int) - - // Position returns (row, column) pair. - Position() (int, int) -} - -type TokenStream interface { - Next() (VToken, error) -} - -type SyntaxError struct { - Row int - Col int - Message string - Token VToken - ExpectedTerminals []string -} - -type ParserOption func(p *Parser) error - -// DisableLAC disables LAC (lookahead correction). LAC is enabled by default. -func DisableLAC() ParserOption { - return func(p *Parser) error { - p.disableLAC = true - return nil - } -} - -func SemanticAction(semAct SemanticActionSet) ParserOption { - return func(p *Parser) error { - p.semAct = semAct - return nil - } -} - -type Parser struct { - toks TokenStream - gram Grammar - stateStack *stateStack - semAct SemanticActionSet - disableLAC bool - onError bool - shiftCount int - synErrs []*SyntaxError -} - -func NewParser(toks TokenStream, gram Grammar, opts ...ParserOption) (*Parser, error) { - p := &Parser{ - toks: toks, - gram: gram, - stateStack: &stateStack{}, - } - - for _, opt := range opts { - err := opt(p) - if err != nil { - return nil, err - } - } - - return p, nil -} - -func (p *Parser) Parse() error { - p.stateStack.push(p.gram.InitialState()) - tok, err := p.nextToken() - if err != nil { - return err - } - -ACTION_LOOP: - for { - act := p.lookupAction(tok) - - switch { - case act < 0: // Shift - nextState := act * -1 - - recovered := false - if p.onError { - p.shiftCount++ - - // When the parser performs shift three times, the parser recovers from the error state. - if p.shiftCount >= 3 { - p.onError = false - p.shiftCount = 0 - recovered = true - } - } - - p.shift(nextState) - - if p.semAct != nil { - p.semAct.Shift(tok, recovered) - } - - tok, err = p.nextToken() - if err != nil { - return err - } - case act > 0: // Reduce - prodNum := act - - recovered := false - if p.onError && p.gram.RecoverProduction(prodNum) { - p.onError = false - p.shiftCount = 0 - recovered = true - } - - accepted := p.reduce(prodNum) - if accepted { - if p.semAct != nil { - p.semAct.Accept() - } - - return nil - } - - if p.semAct != nil { - p.semAct.Reduce(prodNum, recovered) - } - default: // Error - if p.onError { - tok, err = p.nextToken() - if err != nil { - return err - } - if tok.EOF() { - if p.semAct != nil { - p.semAct.MissError(tok) - } - - return nil - } - - continue ACTION_LOOP - } - - row, col := tok.Position() - p.synErrs = append(p.synErrs, &SyntaxError{ - Row: row, - Col: col, - Message: "unexpected token", - Token: tok, - ExpectedTerminals: p.searchLookahead(p.stateStack.top()), - }) - - count, ok := p.trapError() - if !ok { - if p.semAct != nil { - p.semAct.MissError(tok) - } - - return nil - } - - p.onError = true - p.shiftCount = 0 - - act, err := p.lookupActionOnError() - if err != nil { - return err - } - - p.shift(act * -1) - - if p.semAct != nil { - p.semAct.TrapAndShiftError(tok, count) - } - } - } -} - -// validateLookahead validates whether `term` is a valid lookahead in the current context. When `term` is valid, -// this method returns `true`. -func (p *Parser) validateLookahead(term int) bool { - p.stateStack.enableExploratoryMode() - defer p.stateStack.disableExploratoryMode() - - for { - act := p.gram.Action(p.stateStack.topExploratorily(), term) - - switch { - case act < 0: // Shift - return true - case act > 0: // Reduce - prodNum := act - - lhs := p.gram.LHS(prodNum) - if lhs == p.gram.LHS(p.gram.StartProduction()) { - return true - } - n := p.gram.AlternativeSymbolCount(prodNum) - p.stateStack.popExploratorily(n) - state := p.gram.GoTo(p.stateStack.topExploratorily(), lhs) - p.stateStack.pushExploratorily(state) - default: // Error - return false - } - } -} - -func (p *Parser) nextToken() (VToken, error) { - for { - // We don't have to check whether the token is invalid because the kind ID of the invalid token is 0, - // and the parsing table doesn't have an entry corresponding to the kind ID 0. Thus we can detect - // a syntax error because the parser cannot find an entry corresponding to the invalid token. - tok, err := p.toks.Next() - if err != nil { - return nil, err - } - - if p.gram.SkipTerminal(tok.TerminalID()) { - continue - } - - return tok, nil - } -} - -func (p *Parser) tokenToTerminal(tok VToken) int { - if tok.EOF() { - return p.gram.EOF() - } - - return tok.TerminalID() -} - -func (p *Parser) lookupAction(tok VToken) int { - if !p.disableLAC { - term := p.tokenToTerminal(tok) - if !p.validateLookahead(term) { - return 0 - } - } - - return p.gram.Action(p.stateStack.top(), p.tokenToTerminal(tok)) -} - -func (p *Parser) lookupActionOnError() (int, error) { - act := p.gram.Action(p.stateStack.top(), p.gram.Error()) - if act >= 0 { - return 0, fmt.Errorf("an entry must be a shift action by the error symbol; entry: %v, state: %v, symbol: %v", act, p.stateStack.top(), p.gram.Terminal(p.gram.Error())) - } - - return act, nil -} - -func (p *Parser) shift(nextState int) { - p.stateStack.push(nextState) -} - -func (p *Parser) reduce(prodNum int) bool { - lhs := p.gram.LHS(prodNum) - if lhs == p.gram.LHS(p.gram.StartProduction()) { - return true - } - n := p.gram.AlternativeSymbolCount(prodNum) - p.stateStack.pop(n) - nextState := p.gram.GoTo(p.stateStack.top(), lhs) - p.stateStack.push(nextState) - return false -} - -func (p *Parser) trapError() (int, bool) { - count := 0 - for { - if p.gram.ErrorTrapperState(p.stateStack.top()) { - return count, true - } - - if p.stateStack.top() != p.gram.InitialState() { - p.stateStack.pop(1) - count++ - } else { - return 0, false - } - } -} - -func (p *Parser) SyntaxErrors() []*SyntaxError { - return p.synErrs -} - -func (p *Parser) searchLookahead(state int) []string { - kinds := []string{} - termCount := p.gram.TerminalCount() - for term := 0; term < termCount; term++ { - if p.disableLAC { - if p.gram.Action(p.stateStack.top(), term) == 0 { - continue - } - } else { - if !p.validateLookahead(term) { - continue - } - } - - // We don't add the error symbol to the look-ahead symbols because users cannot input the error symbol - // intentionally. - if term == p.gram.Error() { - continue - } - - kinds = append(kinds, p.gram.Terminal(term)) - } - - return kinds -} - -type stateStack struct { - items []int - itemsExp []int -} - -func (s *stateStack) enableExploratoryMode() { - s.itemsExp = make([]int, len(s.items)) - copy(s.itemsExp, s.items) -} - -func (s *stateStack) disableExploratoryMode() { - s.itemsExp = nil -} - -func (s *stateStack) top() int { - return s.items[len(s.items)-1] -} - -func (s *stateStack) topExploratorily() int { - return s.itemsExp[len(s.itemsExp)-1] -} - -func (s *stateStack) push(state int) { - s.items = append(s.items, state) -} - -func (s *stateStack) pushExploratorily(state int) { - s.itemsExp = append(s.itemsExp, state) -} - -func (s *stateStack) pop(n int) { - s.items = s.items[:len(s.items)-n] -} - -func (s *stateStack) popExploratorily(n int) { - s.itemsExp = s.itemsExp[:len(s.itemsExp)-n] -} diff --git a/src/urubu/driver/parser/semantic_action.go b/src/urubu/driver/parser/semantic_action.go deleted file mode 100644 index 6bb78cf..0000000 --- a/src/urubu/driver/parser/semantic_action.go +++ /dev/null @@ -1,371 +0,0 @@ -package parser - -import ( - "encoding/json" - "fmt" - "io" - "strconv" -) - -// SemanticActionSet is a set of semantic actions a parser calls. -type SemanticActionSet interface { - // Shift runs when the parser shifts a symbol onto a state stack. `tok` is a token corresponding to the symbol. - // When the parser recovered from an error state by shifting the token, `recovered` is true. - Shift(tok VToken, recovered bool) - - // Reduce runs when the parser reduces an RHS of a production to its LHS. `prodNum` is a number of the production. - // When the parser recovered from an error state by reducing the production, `recovered` is true. - Reduce(prodNum int, recovered bool) - - // Accept runs when the parser accepts an input. - Accept() - - // TrapAndShiftError runs when the parser traps a syntax error and shifts a error symbol onto the state stack. - // `cause` is a token that caused a syntax error. `popped` is the number of frames that the parser discards - // from the state stack. - // Unlike `Shift` function, this function doesn't take a token to be shifted as an argument because a token - // corresponding to the error symbol doesn't exist. - TrapAndShiftError(cause VToken, popped int) - - // MissError runs when the parser fails to trap a syntax error. `cause` is a token that caused a syntax error. - MissError(cause VToken) -} - -var _ SemanticActionSet = &SyntaxTreeActionSet{} - -// SyntaxTreeNode is a node of a syntax tree. A node type used in SyntaxTreeActionSet must implement SyntaxTreeNode interface. -type SyntaxTreeNode interface { - // ChildCount returns a child count of a node. A parser calls this method to know the child count to be expanded by an `#ast` - // directive with `...` operator. - ChildCount() int - - // ExpandChildren returns children of a node. A parser calls this method to fetch the children to be expanded by an `#ast` - // directive with `...` operator. - ExpandChildren() []SyntaxTreeNode -} - -var _ SyntaxTreeNode = &Node{} - -// SyntaxTreeBuilder allows you to construct a syntax tree containing arbitrary user-defined node types. -// The parser uses SyntaxTreeBuilder interface as a part of semantic actions via SyntaxTreeActionSet interface. -type SyntaxTreeBuilder interface { - Shift(kindName string, tok VToken) SyntaxTreeNode - ShiftError(kindName string) SyntaxTreeNode - Reduce(kindName string, children []SyntaxTreeNode) SyntaxTreeNode - Accept(f SyntaxTreeNode) -} - -var _ SyntaxTreeBuilder = &DefaultSyntaxTreeBuilder{} - -// DefaultSyntaxTreeBuilder is a implementation of SyntaxTreeBuilder. -type DefaultSyntaxTreeBuilder struct { - tree *Node -} - -// NewDefaultSyntaxTreeBuilder returns a new DefaultSyntaxTreeBuilder. -func NewDefaultSyntaxTreeBuilder() *DefaultSyntaxTreeBuilder { - return &DefaultSyntaxTreeBuilder{} -} - -// Shift is a implementation of SyntaxTreeBuilder.Shift. -func (b *DefaultSyntaxTreeBuilder) Shift(kindName string, tok VToken) SyntaxTreeNode { - bytePos, byteLen := tok.BytePosition() - row, col := tok.Position() - return &Node{ - Type: NodeTypeTerminal, - KindName: kindName, - Text: string(tok.Lexeme()), - BytePos: bytePos, - ByteLen: byteLen, - Row: row, - Col: col, - } -} - -// ShiftError is a implementation of SyntaxTreeBuilder.ShiftError. -func (b *DefaultSyntaxTreeBuilder) ShiftError(kindName string) SyntaxTreeNode { - return &Node{ - Type: NodeTypeError, - KindName: kindName, - } -} - -// Reduce is a implementation of SyntaxTreeBuilder.Reduce. -func (b *DefaultSyntaxTreeBuilder) Reduce(kindName string, children []SyntaxTreeNode) SyntaxTreeNode { - cNodes := make([]*Node, len(children)) - for i, c := range children { - cNodes[i] = c.(*Node) - } - return &Node{ - Type: NodeTypeNonTerminal, - KindName: kindName, - Children: cNodes, - } -} - -// Accept is a implementation of SyntaxTreeBuilder.Accept. -func (b *DefaultSyntaxTreeBuilder) Accept(f SyntaxTreeNode) { - b.tree = f.(*Node) -} - -// Tree returns a syntax tree when the parser has accepted an input. If a syntax error occurs, the return value is nil. -func (b *DefaultSyntaxTreeBuilder) Tree() *Node { - return b.tree -} - -// SyntaxTreeActionSet is a implementation of SemanticActionSet interface and constructs a syntax tree. -type SyntaxTreeActionSet struct { - gram Grammar - builder SyntaxTreeBuilder - semStack *semanticStack - disableASTAction bool -} - -// NewASTActionSet returns a new SyntaxTreeActionSet that constructs an AST (Abstract Syntax Tree). -// When grammar `gram` contains `#ast` directives, the new SyntaxTreeActionSet this function returns interprets them. -func NewASTActionSet(gram Grammar, builder SyntaxTreeBuilder) *SyntaxTreeActionSet { - return &SyntaxTreeActionSet{ - gram: gram, - builder: builder, - semStack: newSemanticStack(), - } -} - -// NewCSTTActionSet returns a new SyntaxTreeActionSet that constructs a CST (Concrete Syntax Tree). -// Even if grammar `gram` contains `#ast` directives, the new SyntaxTreeActionSet this function returns ignores them. -func NewCSTActionSet(gram Grammar, builder SyntaxTreeBuilder) *SyntaxTreeActionSet { - return &SyntaxTreeActionSet{ - gram: gram, - builder: builder, - semStack: newSemanticStack(), - disableASTAction: true, - } -} - -// Shift is a implementation of SemanticActionSet.Shift method. -func (a *SyntaxTreeActionSet) Shift(tok VToken, recovered bool) { - term := a.tokenToTerminal(tok) - a.semStack.push(a.builder.Shift(a.gram.Terminal(term), tok)) -} - -// Reduce is a implementation of SemanticActionSet.Reduce method. -func (a *SyntaxTreeActionSet) Reduce(prodNum int, recovered bool) { - lhs := a.gram.LHS(prodNum) - - // When an alternative is empty, `n` will be 0, and `handle` will be empty slice. - n := a.gram.AlternativeSymbolCount(prodNum) - handle := a.semStack.pop(n) - - var astAct []int - if !a.disableASTAction { - astAct = a.gram.ASTAction(prodNum) - } - var children []SyntaxTreeNode - if astAct != nil { - // Count the number of children in advance to avoid frequent growth in a slice for children. - { - l := 0 - for _, e := range astAct { - if e > 0 { - l++ - } else { - offset := e*-1 - 1 - l += handle[offset].ChildCount() - } - } - - children = make([]SyntaxTreeNode, l) - } - - p := 0 - for _, e := range astAct { - if e > 0 { - offset := e - 1 - children[p] = handle[offset] - p++ - } else { - offset := e*-1 - 1 - for _, c := range handle[offset].ExpandChildren() { - children[p] = c - p++ - } - } - } - } else { - // If an alternative has no AST action, a driver generates - // a node with the same structure as a CST. - children = handle - } - - a.semStack.push(a.builder.Reduce(a.gram.NonTerminal(lhs), children)) -} - -// Accept is a implementation of SemanticActionSet.Accept method. -func (a *SyntaxTreeActionSet) Accept() { - top := a.semStack.pop(1) - a.builder.Accept(top[0]) -} - -// TrapAndShiftError is a implementation of SemanticActionSet.TrapAndShiftError method. -func (a *SyntaxTreeActionSet) TrapAndShiftError(cause VToken, popped int) { - a.semStack.pop(popped) - a.semStack.push(a.builder.ShiftError(a.gram.Terminal(a.gram.Error()))) -} - -// MissError is a implementation of SemanticActionSet.MissError method. -func (a *SyntaxTreeActionSet) MissError(cause VToken) { -} - -func (a *SyntaxTreeActionSet) tokenToTerminal(tok VToken) int { - if tok.EOF() { - return a.gram.EOF() - } - - return tok.TerminalID() -} - -type semanticStack struct { - frames []SyntaxTreeNode -} - -func newSemanticStack() *semanticStack { - return &semanticStack{ - frames: make([]SyntaxTreeNode, 0, 100), - } -} - -func (s *semanticStack) push(f SyntaxTreeNode) { - s.frames = append(s.frames, f) -} - -func (s *semanticStack) pop(n int) []SyntaxTreeNode { - fs := s.frames[len(s.frames)-n:] - s.frames = s.frames[:len(s.frames)-n] - - return fs -} - -type NodeType int - -const ( - NodeTypeError = 0 - NodeTypeTerminal = 1 - NodeTypeNonTerminal = 2 -) - -// Node is a implementation of SyntaxTreeNode interface. -type Node struct { - Type NodeType - KindName string - Text string - BytePos int - ByteLen int - Row int - Col int - Children []*Node -} - -func (n *Node) MarshalJSON() ([]byte, error) { - switch n.Type { - case NodeTypeError: - return json.Marshal(struct { - Type NodeType `json:"type"` - KindName string `json:"kind_name"` - }{ - Type: n.Type, - KindName: n.KindName, - }) - case NodeTypeTerminal: - if n.KindName == "" { - return json.Marshal(struct { - Type NodeType `json:"type"` - Text string `json:"text"` - Row int `json:"row"` - Col int `json:"col"` - }{ - Type: n.Type, - Text: n.Text, - Row: n.Row, - Col: n.Col, - }) - } - return json.Marshal(struct { - Type NodeType `json:"type"` - KindName string `json:"kind_name"` - Text string `json:"text"` - Row int `json:"row"` - Col int `json:"col"` - }{ - Type: n.Type, - KindName: n.KindName, - Text: n.Text, - Row: n.Row, - Col: n.Col, - }) - case NodeTypeNonTerminal: - return json.Marshal(struct { - Type NodeType `json:"type"` - KindName string `json:"kind_name"` - Children []*Node `json:"children"` - }{ - Type: n.Type, - KindName: n.KindName, - Children: n.Children, - }) - default: - return nil, fmt.Errorf("invalid node type: %v", n.Type) - } -} - -// ChildCount is a implementation of SyntaxTreeNode.ChildCount. -func (n *Node) ChildCount() int { - return len(n.Children) -} - -// ExpandChildren is a implementation of SyntaxTreeNode.ExpandChildren. -func (n *Node) ExpandChildren() []SyntaxTreeNode { - fs := make([]SyntaxTreeNode, len(n.Children)) - for i, n := range n.Children { - fs[i] = n - } - return fs -} - -// PrintTree prints a syntax tree whose root is `node`. -func PrintTree(w io.Writer, node *Node) { - printTree(w, node, "", "") -} - -func printTree(w io.Writer, node *Node, ruledLine string, childRuledLinePrefix string) { - if node == nil { - return - } - - switch node.Type { - case NodeTypeError: - fmt.Fprintf(w, "%v%v\n", ruledLine, node.KindName) - case NodeTypeTerminal: - fmt.Fprintf(w, "%v%v %v\n", ruledLine, node.KindName, strconv.Quote(node.Text)) - case NodeTypeNonTerminal: - fmt.Fprintf(w, "%v%v\n", ruledLine, node.KindName) - - num := len(node.Children) - for i, child := range node.Children { - var line string - if num > 1 && i < num-1 { - line = "├─ " - } else { - line = "└─ " - } - - var prefix string - if i >= num-1 { - prefix = " " - } else { - prefix = "│ " - } - - printTree(w, child, childRuledLinePrefix+line, childRuledLinePrefix+prefix) - } - } -} diff --git a/src/urubu/driver/parser/spec.go b/src/urubu/driver/parser/spec.go deleted file mode 100644 index 6dc7c3f..0000000 --- a/src/urubu/driver/parser/spec.go +++ /dev/null @@ -1,73 +0,0 @@ -package parser - -import spec "urubu/spec/grammar" - -type grammarImpl struct { - g *spec.CompiledGrammar -} - -func NewGrammar(g *spec.CompiledGrammar) *grammarImpl { - return &grammarImpl{ - g: g, - } -} - -func (g *grammarImpl) InitialState() int { - return g.g.Syntactic.InitialState -} - -func (g *grammarImpl) StartProduction() int { - return g.g.Syntactic.StartProduction -} - -func (g *grammarImpl) RecoverProduction(prod int) bool { - return g.g.Syntactic.RecoverProductions[prod] != 0 -} - -func (g *grammarImpl) Action(state int, terminal int) int { - return g.g.Syntactic.Action[state*g.g.Syntactic.TerminalCount+terminal] -} - -func (g *grammarImpl) GoTo(state int, lhs int) int { - return g.g.Syntactic.GoTo[state*g.g.Syntactic.NonTerminalCount+lhs] -} - -func (g *grammarImpl) AlternativeSymbolCount(prod int) int { - return g.g.Syntactic.AlternativeSymbolCounts[prod] -} - -func (g *grammarImpl) TerminalCount() int { - return g.g.Syntactic.TerminalCount -} - -func (g *grammarImpl) SkipTerminal(terminal int) bool { - return g.g.Syntactic.TerminalSkip[terminal] == 1 -} - -func (g *grammarImpl) ErrorTrapperState(state int) bool { - return g.g.Syntactic.ErrorTrapperStates[state] != 0 -} - -func (g *grammarImpl) NonTerminal(nonTerminal int) string { - return g.g.Syntactic.NonTerminals[nonTerminal] -} - -func (g *grammarImpl) LHS(prod int) int { - return g.g.Syntactic.LHSSymbols[prod] -} - -func (g *grammarImpl) EOF() int { - return g.g.Syntactic.EOFSymbol -} - -func (g *grammarImpl) Error() int { - return g.g.Syntactic.ErrorSymbol -} - -func (g *grammarImpl) Terminal(terminal int) string { - return g.g.Syntactic.Terminals[terminal] -} - -func (g *grammarImpl) ASTAction(prod int) []int { - return g.g.ASTAction.Entries[prod] -} diff --git a/src/urubu/driver/parser/template.go b/src/urubu/driver/parser/template.go deleted file mode 100644 index 33d097c..0000000 --- a/src/urubu/driver/parser/template.go +++ /dev/null @@ -1,535 +0,0 @@ -package parser - -import ( - "bytes" - _ "embed" - "fmt" - "go/ast" - "go/format" - "go/parser" - "go/token" - goToken "go/token" - "strconv" - "strings" - "text/template" - - spec "urubu/spec/grammar" -) - -// go:embed parser.go -var parserCoreSrc string - -// go:embed semantic_action.go -var semActSrc string - -func GenParser(cgram *spec.CompiledGrammar, pkgName string) ([]byte, error) { - var parserSrc string - { - fset := goToken.NewFileSet() - f, err := parser.ParseFile(fset, "parser.go", parserCoreSrc, parser.ParseComments) - if err != nil { - return nil, err - } - - var b strings.Builder - err = format.Node(&b, fset, f) - if err != nil { - return nil, err - } - - parserSrc = b.String() - } - - var grammarSrc string - { - t, err := template.New("").Funcs(genGrammarTemplateFuncs(cgram)).Parse(grammarSrcTmplate) - if err != nil { - return nil, err - } - - var b strings.Builder - err = t.Execute(&b, map[string]interface{}{ - "initialState": cgram.Syntactic.InitialState, - "startProduction": cgram.Syntactic.StartProduction, - "terminalCount": cgram.Syntactic.TerminalCount, - "nonTerminalCount": cgram.Syntactic.NonTerminalCount, - "eofSymbol": cgram.Syntactic.EOFSymbol, - "errorSymbol": cgram.Syntactic.ErrorSymbol, - }) - if err != nil { - return nil, err - } - - grammarSrc = b.String() - } - - var lexerSrc string - { - t, err := template.New("").Funcs(genLexerTemplateFuncs(cgram)).Parse(lexerSrcTmplate) - if err != nil { - return nil, err - } - - var b strings.Builder - err = t.Execute(&b, nil) - if err != nil { - return nil, err - } - - lexerSrc = b.String() - } - - var src string - { - tmpl := `// Code generated by vartan-go. DO NOT EDIT. -{{ .parserSrc }} - -{{ .grammarSrc }} - -{{ .lexerSrc }} -` - t, err := template.New("").Parse(tmpl) - if err != nil { - return nil, err - } - - var b strings.Builder - err = t.Execute(&b, map[string]string{ - "parserSrc": parserSrc, - "grammarSrc": grammarSrc, - "lexerSrc": lexerSrc, - }) - if err != nil { - return nil, err - } - - src = b.String() - } - - fset := goToken.NewFileSet() - f, err := parser.ParseFile(fset, "", src, parser.ParseComments) - if err != nil { - return nil, err - } - - f.Name = ast.NewIdent(pkgName) - - // Complete an import statement. - for _, d := range f.Decls { - gd, ok := d.(*ast.GenDecl) - if !ok || gd.Tok != token.IMPORT { - continue - } - gd.Specs = append(gd.Specs, &ast.ImportSpec{ - Path: &ast.BasicLit{ - Value: `"io"`, - }, - }) - break - } - - var b bytes.Buffer - err = format.Node(&b, fset, f) - if err != nil { - return nil, err - } - - return b.Bytes(), nil -} - -const grammarSrcTmplate = ` -type grammarImpl struct { - recoverProductions []int - action []int - goTo []int - alternativeSymbolCounts []int - errorTrapperStates []int - nonTerminals []string - lhsSymbols []int - terminals []string - terminalSkip []int - astActions [][]int -} - -func NewGrammar() *grammarImpl { - return &grammarImpl{ - recoverProductions: {{ genRecoverProductions }}, - action: {{ genAction }}, - goTo: {{ genGoTo }}, - alternativeSymbolCounts: {{ genAlternativeSymbolCounts }}, - errorTrapperStates: {{ genErrorTrapperStates }}, - nonTerminals: {{ genNonTerminals }}, - lhsSymbols: {{ genLHSSymbols }}, - terminals: {{ genTerminals }}, - terminalSkip: {{ genTerminalSkip }}, - astActions: {{ genASTActions }}, - } -} - -func (g *grammarImpl) InitialState() int { - return {{ .initialState }} -} - -func (g *grammarImpl) StartProduction() int { - return {{ .startProduction }} -} - -func (g *grammarImpl) RecoverProduction(prod int) bool { - return g.recoverProductions[prod] != 0 -} - -func (g *grammarImpl) Action(state int, terminal int) int { - return g.action[state*{{ .terminalCount }}+terminal] -} - -func (g *grammarImpl) GoTo(state int, lhs int) int { - return g.goTo[state*{{ .nonTerminalCount }}+lhs] -} - -func (g *grammarImpl) AlternativeSymbolCount(prod int) int { - return g.alternativeSymbolCounts[prod] -} - -func (g *grammarImpl) TerminalCount() int { - return {{ .terminalCount }} -} - -func (g *grammarImpl) SkipTerminal(terminal int) bool { - return g.terminalSkip[terminal] == 1 -} - -func (g *grammarImpl) ErrorTrapperState(state int) bool { - return g.errorTrapperStates[state] != 0 -} - -func (g *grammarImpl) NonTerminal(nonTerminal int) string { - return g.nonTerminals[nonTerminal] -} - -func (g *grammarImpl) LHS(prod int) int { - return g.lhsSymbols[prod] -} - -func (g *grammarImpl) EOF() int { - return {{ .eofSymbol }} -} - -func (g *grammarImpl) Error() int { - return {{ .errorSymbol }} -} - -func (g *grammarImpl) Terminal(terminal int) string { - return g.terminals[terminal] -} - -func (g *grammarImpl) ASTAction(prod int) []int { - return g.astActions[prod] -} -` - -func genGrammarTemplateFuncs(cgram *spec.CompiledGrammar) template.FuncMap { - return template.FuncMap{ - "genRecoverProductions": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.RecoverProductions { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genAction": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.Action { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genGoTo": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.GoTo { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genAlternativeSymbolCounts": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.AlternativeSymbolCounts { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genErrorTrapperStates": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.ErrorTrapperStates { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genNonTerminals": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]string{\n") - for _, v := range cgram.Syntactic.NonTerminals { - fmt.Fprintf(&b, "%v,\n", strconv.Quote(v)) - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genLHSSymbols": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.LHSSymbols { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genTerminals": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]string{\n") - for _, v := range cgram.Syntactic.Terminals { - fmt.Fprintf(&b, "%v,\n", strconv.Quote(v)) - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genTerminalSkip": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.TerminalSkip { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - "genASTActions": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[][]int{\n") - for _, entries := range cgram.ASTAction.Entries { - if len(entries) == 0 { - fmt.Fprintf(&b, "nil,\n") - continue - } - - fmt.Fprintf(&b, "{\n") - c := 1 - for _, v := range entries { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "},\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - } -} - -const lexerSrcTmplate = ` -type vToken struct { - terminalID int - tok *Token -} - -func (t *vToken) TerminalID() int { - return t.terminalID -} - -func (t *vToken) Lexeme() []byte { - return t.tok.Lexeme -} - -func (t *vToken) EOF() bool { - return t.tok.EOF -} - -func (t *vToken) Invalid() bool { - return t.tok.Invalid -} - -func (t *vToken) BytePosition() (int, int) { - return t.tok.BytePos, t.tok.ByteLen -} - -func (t *vToken) Position() (int, int) { - return t.tok.Row, t.tok.Col -} - -var kindToTerminal = {{ genKindToTerminal }} - -type tokenStream struct { - lex *Lexer - kindToTerminal []int -} - -func NewTokenStream(src io.Reader) (*tokenStream, error) { - lex, err := NewLexer(NewLexSpec(), src) - if err != nil { - return nil, err - } - - return &tokenStream{ - lex: lex, - }, nil -} - -func (t *tokenStream) Next() (VToken, error) { - tok, err := t.lex.Next() - if err != nil { - return nil, err - } - return &vToken{ - terminalID: kindToTerminal[tok.KindID], - tok: tok, - }, nil -} -` - -func genLexerTemplateFuncs(cgram *spec.CompiledGrammar) template.FuncMap { - return template.FuncMap{ - "genKindToTerminal": func() string { - var b strings.Builder - fmt.Fprintf(&b, "[]int{\n") - c := 1 - for _, v := range cgram.Syntactic.KindToTerminal { - fmt.Fprintf(&b, "%v, ", v) - if c == 20 { - fmt.Fprintf(&b, "\n") - c = 1 - } else { - c++ - } - } - if c > 1 { - fmt.Fprintf(&b, "\n") - } - fmt.Fprintf(&b, "}") - return b.String() - }, - } -} - -func GenSemanticAction(pkgName string) ([]byte, error) { - var src string - { - tmpl := `// Code generated by vartan-go. DO NOT EDIT. -{{ .semActSrc }} -` - t, err := template.New("").Parse(tmpl) - if err != nil { - return nil, err - } - - var b strings.Builder - err = t.Execute(&b, map[string]string{ - "semActSrc": semActSrc, - }) - if err != nil { - return nil, err - } - - src = b.String() - } - - fset := goToken.NewFileSet() - f, err := parser.ParseFile(fset, "", src, parser.ParseComments) - if err != nil { - return nil, err - } - - f.Name = ast.NewIdent(pkgName) - - var b bytes.Buffer - err = format.Node(&b, fset, f) - if err != nil { - return nil, err - } - - return b.Bytes(), nil -} diff --git a/src/urubu/driver/parser/token_stream.go b/src/urubu/driver/parser/token_stream.go deleted file mode 100644 index 788e521..0000000 --- a/src/urubu/driver/parser/token_stream.go +++ /dev/null @@ -1,65 +0,0 @@ -package parser - -import ( - "io" - - "urubu/driver/lexer" - spec "urubu/spec/grammar" -) - -type vToken struct { - terminalID int - tok *lexer.Token -} - -func (t *vToken) TerminalID() int { - return t.terminalID -} - -func (t *vToken) Lexeme() []byte { - return t.tok.Lexeme -} - -func (t *vToken) EOF() bool { - return t.tok.EOF -} - -func (t *vToken) Invalid() bool { - return t.tok.Invalid -} - -func (t *vToken) BytePosition() (int, int) { - return t.tok.BytePos, t.tok.ByteLen -} - -func (t *vToken) Position() (int, int) { - return t.tok.Row, t.tok.Col -} - -type tokenStream struct { - lex *lexer.Lexer - kindToTerminal []int -} - -func NewTokenStream(g *spec.CompiledGrammar, src io.Reader) (TokenStream, error) { - lex, err := lexer.NewLexer(lexer.NewLexSpec(g.Lexical), src) - if err != nil { - return nil, err - } - - return &tokenStream{ - lex: lex, - kindToTerminal: g.Syntactic.KindToTerminal, - }, nil -} - -func (l *tokenStream) Next() (VToken, error) { - tok, err := l.lex.Next() - if err != nil { - return nil, err - } - return &vToken{ - terminalID: l.kindToTerminal[tok.KindID], - tok: tok, - }, nil -} |