What's the meaning of "magic" pragma in nim?

Question

When going through the code in Nim project itself, I find that some proc decorated by "magic" pragma misses proc definition (example). There's no doc to explain the pragma, I guess the proc's definition is somewhere else and is merged while compiling.But I cannot still find the definition by searching the whole project.

Do I misunderstand the "magic" pragma? What's the meaning of it? And how to use it?

Rakeoff

Answer 1

The {.magic.} pragma is used to define built-in operations and types, i.e. anything that requires compiler magic in order to work (hence the name). It is not intended to be used outside the system modules.

Eruptive

Where can I get the definitions of these procs? – Rakeoff

They are all implemented in the compiler. For example, the procedure that you linked to is eventually implemented in the opcParseStmtToAst branch in the rawExecute() procedure in compiler/vm.nim. – Eruptive

In some other languages/VMs, these magic operations are also called intrinsics. See en.wikipedia.org/wiki/Intrinsic_function for additional context. – Penumbra