<MARK( -- DP-mark ) compile-only => "FORTH"
memorizes the current DP on the CS-STACK
used for later. Useful for creation of
compiling words, eg. BEGIN , see AHEAD
simulate:
: <MARK ?COMP HERE ;
primitive code = [p4_backward_mark]
<RESOLVE( DP-mark -- ) compile-only => "FORTH"
resolves a previous , actually pushes
the DP-address memorized at BRANCH or => ?BRANCH in compiling
words like UNTIL
simulate:
: <RESOLVE ?COMP , ;
primitive code = [p4_backward_resolve]
MARK>( -- DP-mark ) compile-only => "FORTH"
makes room for a pointer in the dictionary to
be resolved through RESOLVE> and does therefore
memorize that cell's address on the CS-STACK
Mostly used after BRANCH or => ?BRANCH in compiling
words like IF or ELSE
simulate:
: MARK> ?COMP HERE 0 , ;
primitive code = [p4_forward_mark]
RESOLVE>( DP-mark -- ) compile-only => "FORTH"
resolves a pointer created by MARK>
Mostly used in compiling words like THEN
simulate:
: RESOLVE> ?COMP HERE SWAP ! ;
primitive code = [p4_forward_resolve]
BRANCH( -- ) => "FORTH"
compiles a branch-runtime into the dictionary that
can be resolved with MARK<d or <RESOLVE.
Usage:
BRANCH MARK< or
BRANCH >RESOLVE or ...
this is the runtime-portion of ELSE - the use of
ELSE should be preferred. See also => ?BRANCH
: BRANCH COMPILE (BRANCH) ;
immediate code = [p4_branch]
?BRANCH( -- ) => "FORTH"
compiles a cond-branch-runtime into the dictionary that
can be resolved with >MARK&d or RESOLVE>.
Usage:
?BRANCH MARK< or
?BRANCH >RESOLVE or ...
this is the runtime-portion of IF - the use of
IF should be preferred. See also BRANCH
: ?BRANCH COMPILE (?BRANCH) ;
immediate code = [p4_q_branch]