The most pressing unsolved problem. Assume we have:
type
IfTree = object
condition, thenPart, elsePart: Tree
ProcTree = object
fn: Tree
args: seq[Tree]
UnaryOp = object
arg: Tree
Tree = ref case
of StrValue: string
of IntValue: int
of IfStmt: IfTree
of ProcCall: ProcTree
of Minus, BitwiseNot: UnaryOp
Run
And now we pattern match:
let x = ProcCall(fn: StrValue"abc", args: @[]) # some test data
case x
of StrValue(s):
# s is of type: string
of IfStmt(cond, thenPart, elsePart):
# obvious unpacking: cond, thenPart, elsePart of type: Tree
of ProcCall: ..
of Minus(x):
# is x of type UnaryOp or of type Tree?
Run
