// setConst sets x to the untyped constant for literal lit.
func (x *operand) setConst(tok token.Token, lit string) {
val := exact.MakeFromLiteral(lit, tok)
if val == nil {
// TODO(gri) Should we make it an unknown constant instead?
x.mode = invalid
return
}
var kind BasicKind
switch tok {
case token.INT:
kind = UntypedInt
case token.FLOAT:
kind = UntypedFloat
case token.IMAG:
kind = UntypedComplex
case token.CHAR:
kind = UntypedRune
case token.STRING:
kind = UntypedString
}
x.mode = constant
x.typ = Typ[kind]
x.val = val
}
// number = int_lit [ "p" int_lit ] .
//
func (p *gcParser) parseNumber() (x operand) {
x.mode = constant
// mantissa
mant := exact.MakeFromLiteral(p.parseInt(), token.INT)
assert(mant != nil)
if p.lit == "p" {
// exponent (base 2)
p.next()
exp, err := strconv.ParseInt(p.parseInt(), 10, 0)
if err != nil {
p.error(err)
}
if exp < 0 {
denom := exact.MakeInt64(1)
denom = exact.Shift(denom, token.SHL, uint(-exp))
x.typ = Typ[UntypedFloat]
x.val = exact.BinaryOp(mant, token.QUO, denom)
return
}
if exp > 0 {
mant = exact.Shift(mant, token.SHL, uint(exp))
}
x.typ = Typ[UntypedFloat]
x.val = mant
return
}
x.typ = Typ[UntypedInt]
x.val = mant
return
}