A Nim debugEcho with file, line number, and callsite.

here.nim

import std/macros

# calls debugEcho with the lineInfo
macro here*(x: varargs[typed, `$`]):untyped {.noSideEffect.} =
   {.cast(noSideEffect), warning[Deprecated]:off.}: # callsite is deprecated, there's no alternative: https://github.com/nim-lang/RFCs/issues/387 
    result = newTree(nnkCommand, ident "debugEcho")
    result.add newStrLitNode("--- " & x[0].lineInfo & " ---\n")
    result.add newStrLitNode("    " & callsite().toStrLit().strVal & " -> \n")
    for c in x:
      result.add c