diff options
Diffstat (limited to 'parser/parse.go')
| -rw-r--r-- | parser/parse.go | 50 |
1 files changed, 25 insertions, 25 deletions
diff --git a/parser/parse.go b/parser/parse.go index cfbff27..4f186bd 100644 --- a/parser/parse.go +++ b/parser/parse.go @@ -1,8 +1,6 @@ package parser -import ( - "github.com/gnolang/parscan/scanner" -) +import "github.com/gnolang/parscan/scanner" const ( Stmt = 1 << iota @@ -31,25 +29,29 @@ func (p *Parser) Parse(src string) (n []*Node, err error) { return p.ParseTokens(tokens) } -func (p *Parser) ParseTokens(token []scanner.Token) (roots []*Node, err error) { +func (p *Parser) ParseTokens(tokens []scanner.Token) (roots []*Node, err error) { // TODO: error handling. - var root *Node // current root node - var expr *Node // current expression root node - var prev, c *Node - var lce *Node - for i, t := range token { + var root *Node // current root node + var expr *Node // current expression root node + var prev, c *Node // previous and current nodes + var lce *Node // last complete expression node + unaryOp := map[*Node]bool{} // unaryOp indicates if a node is an unary operator. + + for i, t := range tokens { prev = c c = &Node{ Token: t, Kind: p.Spec[t.Name()].Kind, - unary: t.Kind() == scanner.Operator && (i == 0 || token[i-1].Kind() == scanner.Operator), } - if c.Kind == 0 { + if t.IsOperator() && (i == 0 || tokens[i-1].IsOperator()) { + unaryOp[c] = true + } + if c.Kind == Undefined { switch t.Kind() { case scanner.Number: - c.Kind = p.Spec["#num"].Kind + c.Kind = NumberLit case scanner.Identifier: - c.Kind = p.Spec["#id"].Kind + c.Kind = Ident } } @@ -65,20 +67,20 @@ func (p *Parser) ParseTokens(token []scanner.Token) (roots []*Node, err error) { continue } - if t.Kind() == scanner.Block { + if t.IsBlock() { if expr != nil { - if p.hasBlockProp(c, ExprSep) && p.isExprSep(root) { + if p.hasProp(c, ExprSep) && p.isExprSep(root) { // A bracket block may end a previous expression. root.Child = append(root.Child, expr) expr = nil - } else if p.hasBlockProp(c, Call) && !p.hasProp(root, Decl) && p.canCallToken(token[i-1]) { + } else if p.hasProp(c, Call) && !p.hasProp(root, Decl) && p.canCallToken(tokens[i-1]) { // Handle (possibly nested) call expressions. if lce == nil || lce != expr { // TODO(marc): not general, fix it. lce = prev } lce.Child = []*Node{{Token: lce.Token, Child: lce.Child, Kind: lce.Kind}} lce.Token = scanner.NewToken("Call", c.Pos()) - lce.Kind = p.Spec["#call"].Kind + lce.Kind = CallExpr } } tcont := t.Content() @@ -91,10 +93,10 @@ func (p *Parser) ParseTokens(token []scanner.Token) (roots []*Node, err error) { } // Process the end of an expression or a statement. - if t.Kind() == scanner.Separator { + if t.IsSeparator() { if expr != nil && p.hasProp(root, Stmt) { root.Child = append(root.Child, expr) - if p.hasBlockProp(expr, ExprSep) { + if p.hasProp(expr, ExprSep) { roots = append(roots, root) root = nil } @@ -129,7 +131,7 @@ func (p *Parser) ParseTokens(token []scanner.Token) (roots []*Node, err error) { ep := p.Spec[expr.Content()].Order cp := p.Spec[c.Content()].Order a := expr - if c.unary { + if unaryOp[c] { cp = 0 } if cp != 0 { @@ -143,7 +145,7 @@ func (p *Parser) ParseTokens(token []scanner.Token) (roots []*Node, err error) { c1 := expr for { a = c1 - if c1.unary { + if unaryOp[c1] { c1, c = c, c1 a = c1 if c == expr { @@ -155,7 +157,7 @@ func (p *Parser) ParseTokens(token []scanner.Token) (roots []*Node, err error) { break } c1 = c1.Child[1] - if c1.Token.Kind() != scanner.Operator || c1.unary || cp > p.Spec[c1.Content()].Order { + if !c1.IsOperator() || unaryOp[c1] || cp > p.Spec[c1.Content()].Order { break } } @@ -194,9 +196,7 @@ func (p *Parser) isExprSep(n *Node) bool { return p.Spec[n.Content()].F func (p *Parser) isExpr(n *Node) bool { return !p.isStatement(n) && !p.isExprSep(n) } func (p *Parser) isSep(n *Node) bool { return n.Token.Kind() == scanner.Separator } func (p *Parser) IsBlock(n *Node) bool { return n.Token.Kind() == scanner.Block } -func (p *Parser) hasBlockProp(n *Node, prop uint) bool { - return p.Spec[n.Content()[:n.Start()]].Flags&prop != 0 -} + func (p *Parser) precedenceToken(t scanner.Token) int { s := t.Content() if l := t.Start(); l > 0 { |