Node:Compiling words, Next:The Text Interpreter, Previous:Tokens for Words, Up:Words
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 below) allow
running arbitrary code while compiling a colon definition (exception:
you must not allot dictionary space).