- IMMEDIATE mode words aren't just for the FORTH compiler to use. You can define your
- own IMMEDIATE words too. The IMMEDIATE word toggles the F_IMMED (IMMEDIATE flag) on the
- most recently defined word, or on the current word if you call it in the middle of a
- definition.
+ EXTENDING THE COMPILER ----------------------------------------------------------------------
+
+ Words flagged with IMMEDIATE (F_IMMED) aren't just for the FORTH compiler to use. You can define
+ your own IMMEDIATE words too, and this is a crucial aspect when extending basic FORTH, because
+ it allows you in effect to extend the compiler itself. Does gcc let you do that?
+
+ Standard FORTH words like IF, WHILE, .", [ and so on are all written as extensions to the basic
+ compiler, and are all IMMEDIATE words.
+
+ The IMMEDIATE word toggles the F_IMMED (IMMEDIATE flag) on the most recently defined word,
+ or on the current word if you call it in the middle of a definition.