Could you explain how/why it works?
I have reproduced that pattern in my project and it works **sometimes but not
always** , and I don't understand why.
When it does not work, I have changed the `callApi` template to be like:
template callApi =
when declaredInScope(inFoo):
callApiFromFoo()
elif declaredInScope(inBar):
callApiFromBar()
else:
echo "inFoo scope? = ", declaredInScope(inFoo)
echo "inBar scope? = ", decalredInScope(inBar)
error("You can call API only in foo or bar scopes!")
Run
And in the `foobar` proc (a macro in my case), I dump the whole AST tree. I can
see that `inFoo` or `inBar` are correctly defined and deeper in the tree I find
LetSection
IdentDefs
PragmaExpr
Ident "inFoo"
Pragma
Ident "inject"
Ident "used"
Sym "Bool"
Call
...
Command
Ident "echo"
Call
Ident "callApi"
Run
(in that specific case, `callApi` returns a `string`)
But the call `callApi` goes in the `else:` branch and I see
echo ["inFoo scope? = ", "false"]
echo ["inBar scope? = ", "false"]
error("You can call API only in foo or bar scopes!",
nil)
Run
The case where it fails is more complex than this example. It is like
`declaredInScope` does not return the correct result in that particular
situation. I've tried to look at the code for `declaredInScope` but that's a
[magic
function](https://github.com/nim-lang/Nim/blob/version-1-2/lib/system.nim#L163)
and I can't find it to understand how it works.
In case it could be useful to find the source of the problem, compilation fails
with the error message (which is true because `callApi` expects to return a
`string` but that's the error case...)
Error: expression has no type:
echo ["inFoo scope? = ", "false"]
echo ["inBar scope? = ", "false"]
error("You can call API only in foo or bar scopes!",
nil)
Run
