// typEnumDecl type checks enum declarations.
func (c *checker) typEnumDecl(e *ast.EnumDecl) Type {
var values []*Const
c.iota = constant.MakeInt64(-1)
for _, e := range e.List {
var x operand
if e.X != nil {
c.constExpr(&x, e.X)
if x.mode == invalid {
return Typ[Invalid]
}
} else {
x.val = constant.BinaryOp(c.iota, scan.Plus, constant.MakeInt64(1))
}
c.iota = x.val
pos := e.Name.Span().Start
name := e.Name.Name
obj := NewConst(pos, name, Typ[Int], c.iota)
values = append(values, obj)
c.declare(Ord, c.scope, e.Name, obj, scan.NoPos)
}
t := new(Enum)
t.values = values
return t
}
// binary type checks a binary expression.
func (c *checker) binary(x *operand, lhs, rhs ast.Expr, op scan.Type) {
var y operand
c.expr(x, lhs)
c.expr(&y, rhs)
if x.mode == invalid {
return
}
if y.mode == invalid {
x.mode = invalid
x.expr = y.expr
return
}
_, hasAssign := c.assignOp(op)
switch {
case op == scan.Comma:
// nothing
case op == scan.Assign || hasAssign:
c.assignment(x, &y)
if x.mode == invalid {
return
}
if !hasAssign {
break
}
fallthrough
default:
if !c.op(binaryOpPredicates, x, op) || !c.op(binaryOpPredicates, &y, op) {
x.mode = invalid
return
}
}
if x.mode == constant_ && y.mode == constant_ && validConstBinOp(op) {
x.val = constant.BinaryOp(x.val, op, y.val)
return
}
x.typ = c.binaryCast(*x, y, op)
x.mode = value
}