global

global pragma

The global pragma can be applied to a variable within a proc to instruct the compiler to store it in a global location and initialize it once at program startup.

proc isHexNumber(s: string): bool =
var pattern {.global.} = re"[0-9a-fA-F]+"
result = s.match(pattern)

When used within a generic proc, a separate unique global variable will be created for each instantiation of the proc. The order of initialization of the created global variables within a module is not defined, but all of them will be initialized after any top-level variables in their originating module and before any variable in a module that imports it.