Can't use bigint as count for repeat

[jfhamlin]

Actual

user=> (repeat 2N 1)
argument 0: cannot coerce *lang.BigInt to int64

Expected

user=> (repeat 2N 1)
(1 1)

[mateodif]

I've been looking into this issue.

Here's what I got so far:
The coercion of values happens in coerceGoValue, in apply.go.

• There are a couple special cases (for Slice and Func) and a default case that should handle the rest.
• We don't seem to handle pointers, which is the case for this particular issue (*lang.BigInt). This can be easily fixed by checking for reflect.Ptr in the default case.
• BigInt, BigDecimal, etc are wrappers of their native types i.e. big.Int, big.Decimal respectively.
  • This causes the Convert function of reflect to not be able to know how to convert the type to, for example, int64.
  • These wrapper types have internal methods for converting to types such as Int64(), String(), etc.

A way of going around this issue would be to use something like MethodByName and check for methods with the same name as the targetType. This is a bit ugly, and we have the issue that MethodByName is case sensitive, although that could be easily fixed by getting the native type as a string and doing .Title() to it or with a helper function.

I have a working solution based on these points, but I recognize that it's an ugly hack. Let me know your thoughts.

[jfhamlin]

Thanks for taking a look! I'm afk right now so I may be mistaken on some of this, but I think the ideal solve here is a dedicated Go implementation of Repeat for BigInt that supports the arbitrarily large count that it implies. When in doubt, refer to clojure's source for this: both core.clj and the core Java classes.

[jfhamlin]

Looks like my memory on this was dodgy re Clojure's support for Repeat, and you're probably on the right track here!