pfe-locals-ext ? Locals + extensions
(LOCAL) ?=>? ( | ); | ? |
"[ANS] FORTH";LOCALS| ( xN ... x2 x1 [name1 .. nameN <|>] -- ) ?=>? ( | ); | ? |
"[ANS] FORTH";LVALUE ( value [name] -- ) ?=>? ( | ); | ? |
"EXTENSIONS";LBUFFER: ( size [name] -- ) ?=>? ( | ); | ? |
"EXTENSIONS";"ENVIRONMENT #LOCALS" ( -- number ) * the number of local names allowed during compilation. * portable programs can check this with => ENVIRONMENT?
(LOCAL) - no description, sorry
LOCALS| ( xN ... x2 x1 [name1 .. nameN <|>] -- ) => "[ANS] FORTH"
create local identifiers to be used in the current definition.
At runtime, each identifier will be assigned a value from
the parameter stack.
The identifiers may be treated as if being a VALUE , it does
also implement the ansi TO extensions for locals. Note that
the identifiers are only valid inside the currently compiled
word, the SEE decompiled word will show them as
<A> <B> ... <N> a.s.o.
see also LVALUE
LVALUE ( value [name] -- ) => "EXTENSIONS"
declares a single local VALUE using (LOCAL) - a
sequence of LVALUE declarations can replace a
LOCALS| argument, ie. LOCALS| a b c |
is the same as LVALUE a LVALUE b LVALUE c .
This should also clarify the runtime stack behaviour of
LOCALS| where the stack parameters seem to be
assigned in reverse order as opposed to their textual
identifier declarations.
compare with VALUE and the pfe's convenience word
VAR.
: LVALUE
STATE @ IF
VALUE
ELSE
BL WORD COUNT DUP (LOCAL) (TO)
THEN
; IMMEDIATE
LBUFFER: ( size [name] -- ) => "EXTENSIONS"
declares a single local VALUE using (LOCAL) - which
will hold the address of an area like BUFFER: but carved
from the return-stack (as in C with alloca). This local buffer
will be automatically given up at the end of the word. The
return-stack-pointer will be increased only at the time of
this function (and the address assigned to the LVALUE)
so that the provided size gets determined at runtime. Note
that in some configurations the forth-return-stack area is
quite small - for large string operations you should consider
to use a POCKET-PAD in pfe.
: LBUFFER:
STATE @ IF
BUFFER:
ELSE
:NONAME ( size -- rp* ) R> RP@ - DUP RP! SWAP >R ;NONAME
COMPILE, POSTPONE LVALUE
THEN
; IMMEDIATE