// MakeConst makes an ideal constant from a literal
// token and the corresponding literal string.
func MakeConst(tok token.Token, lit string) Const {
switch tok {
case token.INT:
var x big.Int
_, ok := x.SetString(lit, 0)
assert(ok)
return Const{&x}
case token.FLOAT:
var y big.Rat
_, ok := y.SetString(lit)
assert(ok)
return Const{&y}
case token.IMAG:
assert(lit[len(lit)-1] == 'i')
var im big.Rat
_, ok := im.SetString(lit[0 : len(lit)-1])
assert(ok)
return Const{cmplx{big.NewRat(0, 1), &im}}
case token.CHAR:
assert(lit[0] == '\'' && lit[len(lit)-1] == '\'')
code, _, _, err := strconv.UnquoteChar(lit[1:len(lit)-1], '\'')
assert(err == nil)
return Const{big.NewInt(int64(code))}
case token.STRING:
s, err := strconv.Unquote(lit)
assert(err == nil)
return Const{s}
}
panic("unreachable")
}
