In contrast to most other languages, Forth has no strict boundary
between compilation and run-time. E.g., you can run arbitrary code
between defining words (or for computing data used by defining words
like constant). Moreover, Immediate
(see Interpretation and Compilation Semantics) and
[...] (see see Literals) allow running arbitrary
code while compiling a colon definition (exception: any dictionary space you allot must be in a different section, see Sections).