diff options
Diffstat (limited to 'parser/expr.go')
| -rw-r--r-- | parser/expr.go | 52 |
1 files changed, 27 insertions, 25 deletions
diff --git a/parser/expr.go b/parser/expr.go index 1944827..149b5e2 100644 --- a/parser/expr.go +++ b/parser/expr.go @@ -17,9 +17,9 @@ func (p *Parser) parseExpr(in Tokens, typeStr string) (out Tokens, err error) { var ops Tokens var ctype string - popop := func() (t scanner.Token) { + popop := func() scanner.Token { l := len(ops) - 1 - t = ops[l] + t := ops[l] ops = ops[:l] if t.Tok.IsLogicalOp() { t.Tok = lang.Label // Implement conditional branching directly. @@ -27,6 +27,15 @@ func (p *Parser) parseExpr(in Tokens, typeStr string) (out Tokens, err error) { return t } + // addop adds an operator to the operator stack. + addop := func(t scanner.Token) { + // Operators on stack with a lower precedence are poped out and output first. + for len(ops) > 0 && p.precedence(t) < p.precedence(ops[len(ops)-1]) { + out = append(out, popop()) + } + ops = append(ops, t) + } + lin := len(in) for i := 0; i < lin; i++ { switch t := in[i]; t.Tok { @@ -47,18 +56,19 @@ func (p *Parser) parseExpr(in Tokens, typeStr string) (out Tokens, err error) { case lang.Period: // TODO: fail if next is not an ident. t.Str += in[i+1].Str // Hardwire selector argument. - for len(ops) > 0 && p.precedence(t) < p.precedence(ops[len(ops)-1]) { - out = append(out, popop()) - } - ops = append(ops, t) + addop(t) i++ // Skip over next ident. + case lang.Next: + out = append(out, t) + + case lang.Range: + ops = ops[:len(ops)-1] // Suppress previous assign or define. + addop(t) + case lang.Colon: t.Str = typeStr - for len(ops) > 0 && p.precedence(t) < p.precedence(ops[len(ops)-1]) { - out = append(out, popop()) - } - ops = append(ops, t) + addop(t) case lang.Add, lang.And, lang.Assign, lang.Define, lang.Equal, lang.Greater, lang.Less, lang.Mul, lang.Not, lang.Sub, lang.Shl, lang.Shr: if i == 0 || in[i-1].Tok.IsOperator() { @@ -66,30 +76,21 @@ func (p *Parser) parseExpr(in Tokens, typeStr string) (out Tokens, err error) { t.Tok = lang.UnaryOp[t.Tok] // FIXME: parsetype for composite if & or * } - for len(ops) > 0 && p.precedence(t) < p.precedence(ops[len(ops)-1]) { - out = append(out, popop()) - } - ops = append(ops, t) + addop(t) case lang.Land: - for len(ops) > 0 && p.precedence(t) < p.precedence(ops[len(ops)-1]) { - out = append(out, popop()) - } + addop(t) xp := strconv.Itoa(p.labelCount[p.scope]) p.labelCount[p.scope]++ out = append(out, scanner.Token{Tok: lang.JumpSetFalse, Str: p.scope + "x" + xp}) - t.Str = p.scope + "x" + xp - ops = append(ops, t) + ops[len(ops)-1].Str = p.scope + "x" + xp case lang.Lor: - for len(ops) > 0 && p.precedence(t) < p.precedence(ops[len(ops)-1]) { - out = append(out, popop()) - } + addop(t) xp := strconv.Itoa(p.labelCount[p.scope]) p.labelCount[p.scope]++ out = append(out, scanner.Token{Tok: lang.JumpSetTrue, Str: p.scope + "x" + xp}) - t.Str = p.scope + "x" + xp - ops = append(ops, t) + ops[len(ops)-1].Str = p.scope + "x" + xp case lang.Ident: s, sc, ok := p.Symbols.Get(t.Str, p.scope) @@ -145,7 +146,8 @@ func (p *Parser) parseExpr(in Tokens, typeStr string) (out Tokens, err error) { return out, err } ctype = typ.String() - p.Symbols.Add(symbol.UnsetAddr, ctype, vm.NewValue(typ), symbol.Type, typ, p.funcScope != "") + // p.Symbols.Add(symbol.UnsetAddr, ctype, vm.NewValue(typ), symbol.Type, typ, p.funcScope != "") + p.Symbols.Add(symbol.UnsetAddr, ctype, vm.NewValue(typ), symbol.Type, typ, false) out = append(out, scanner.Token{Tok: lang.Ident, Pos: t.Pos, Str: ctype}) i += n - 1 break |