default_cost.json

{
    "num" : 1,
    "bool": 1,
    "hole": 0,
    "lambda": 1,
    "_let": 10,
    "list": 1,
    "tree": 100,
    "var ": 1,
    "call": {
        "foldr": 30,
        "foldl": 30,
        "foldt": 30,
        "map": 20,
        "mapt": 20,
        "filter": 20
    },
    "call_default": 10
}