When an empty nkArgList `varargs[untyped]` is passed around it is now
reused for efficiency sake and to prevent the introduction of a spurious
element: before this commit we'd pass the caller a
nkArgList[nkHiddenStdConv[nkBracket]] node instead of just an empty
nkArgList.
Fixes#8706
This is a temporary fix that will be reworked in a follow up commit
that aims to eliminate the tfExplicit flag from the compiler. The
complete and proper fix was considered too risky for inclusion just
before our 0.19 release.
* late instantiation for the generic procs' default param values
* automatic mixin behaviour in concepts
Other fixes:
* don't render the automatically inserted default params in calls
* better rendering of tyFromExpr
This resulted in a codegen error in C++ mode, because the generic
types were not defined in modules where calls requiring downcasts
were used (generating a downcast forces the inclusion of the full
definition of the involved types).
This enables macros accepting arbitrary keyword arguments:
log("foo", prop1 = "bar", prop2 = "baz")
As an added bonus, simple templates with varargs arguments can now
forward their params to procs accepting keyword arguments.
This allows you to pass a template or a macro to another macro
which can then inspect the implementation of the former template/macro
using `getImpl`.
Since templates can be freely redefined, this allows you to treat
their symbols as compile-time variables that have lexical scope.
A motivating PoC example for a logging library taking advantage of
this will be provided in the next commit.
Implementation details:
* The name of a template or a macro will be consider a symbol if
the template/macro requires parameters
* For parameterless templates/macros, you can use `bindSym`, which
was extended to also work outside of compile-time procs.
