version 1.23, 1996/07/16 20:57:09
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version 1.57, 2005/12/31 15:46:08
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\ A powerful locals implementation |
\ A powerful locals implementation |
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\ Copyright (C) 1995 Free Software Foundation, Inc. |
\ Copyright (C) 1995,1996,1997,1998,2000,2003,2004,2005 Free Software Foundation, Inc. |
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\ This file is part of Gforth. |
\ This file is part of Gforth. |
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\ You should have received a copy of the GNU General Public License |
\ You should have received a copy of the GNU General Public License |
\ along with this program; if not, write to the Free Software |
\ along with this program; if not, write to the Free Software |
\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. |
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\ More documentation can be found in the manual and in |
\ More documentation can be found in the manual and in |
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\ Currently locals may only be |
\ Currently locals may only be |
\ defined at the outer level and TO is not supported. |
\ defined at the outer level and TO is not supported. |
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require search-order.fs |
require search.fs |
require float.fs |
require float.fs |
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require extend.fs \ for case |
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: compile-@local ( n -- ) \ gforth compile-fetch-local |
: compile-@local ( n -- ) \ gforth compile-fetch-local |
case |
case |
Line 104 require float.fs
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Line 105 require float.fs
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( otherwise ) dup postpone f@local# , |
( otherwise ) dup postpone f@local# , |
endcase ; |
endcase ; |
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\ locals stuff needed for control structures |
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: compile-lp+! ( n -- ) \ gforth compile-l-p-plus-store |
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dup negate locals-size +! |
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0 over = if |
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else -1 cells over = if postpone lp- |
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else 1 floats over = if postpone lp+ |
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else 2 floats over = if postpone lp+2 |
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else postpone lp+!# dup , |
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then then then then drop ; |
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: adjust-locals-size ( n -- ) \ gforth |
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\ sets locals-size to n and generates an appropriate lp+! |
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locals-size @ swap - compile-lp+! ; |
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\ the locals stack grows downwards (see primitives) |
\ the locals stack grows downwards (see primitives) |
\ of the local variables of a group (in braces) the leftmost is on top, |
\ of the local variables of a group (in braces) the leftmost is on top, |
\ i.e. by going onto the locals stack the order is reversed. |
\ i.e. by going onto the locals stack the order is reversed. |
Line 114 require float.fs
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Line 130 require float.fs
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slowvoc @ |
slowvoc @ |
slowvoc on \ we want a linked list for the vocabulary locals |
slowvoc on \ we want a linked list for the vocabulary locals |
vocabulary locals \ this contains the local variables |
vocabulary locals \ this contains the local variables |
' locals >body ' locals-list >body ! |
' locals >body wordlist-id ' locals-list >body ! |
slowvoc ! |
slowvoc ! |
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create locals-buffer 1000 allot \ !! limited and unsafe |
create locals-buffer 1000 allot \ !! limited and unsafe |
Line 142 variable locals-dp \ so here's the speci
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Line 158 variable locals-dp \ so here's the speci
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swap ! |
swap ! |
postpone >l ; |
postpone >l ; |
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\ locals list operations |
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: common-list ( list1 list2 -- list3 ) \ gforth-internal |
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\ list1 and list2 are lists, where the heads are at higher addresses than |
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\ the tail. list3 is the largest sublist of both lists. |
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begin |
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2dup u<> |
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while |
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2dup u> |
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if |
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swap |
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then |
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@ |
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repeat |
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drop ; |
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: sub-list? ( list1 list2 -- f ) \ gforth-internal |
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\ true iff list1 is a sublist of list2 |
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begin |
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2dup u< |
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while |
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@ |
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repeat |
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= ; |
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: list-size ( list -- u ) \ gforth-internal |
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\ size of the locals frame represented by list |
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0 ( list n ) |
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begin |
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over 0<> |
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while |
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over |
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((name>)) >body @ max |
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swap @ swap ( get next ) |
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repeat |
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faligned nip ; |
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: set-locals-size-list ( list -- ) |
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dup locals-list ! |
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list-size locals-size ! ; |
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: check-begin ( list -- ) |
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\ warn if list is not a sublist of locals-list |
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locals-list @ sub-list? 0= if |
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\ !! print current position |
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." compiler was overly optimistic about locals at a BEGIN" cr |
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\ !! print assumption and reality |
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then ; |
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: compile-pushlocal-f ( a-addr -- ) ( run-time: f -- ) |
: compile-pushlocal-f ( a-addr -- ) ( run-time: f -- ) |
locals-size @ alignlp-f float+ dup locals-size ! |
locals-size @ alignlp-f float+ dup locals-size ! |
swap ! |
swap ! |
Line 228 locals-types definitions
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Line 293 locals-types definitions
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postpone laddr# @ lp-offset, ; |
postpone laddr# @ lp-offset, ; |
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\ you may want to make comments in a locals definitions group: |
\ you may want to make comments in a locals definitions group: |
' \ alias \ immediate |
' \ alias \ ( compilation 'ccc<newline>' -- ; run-time -- ) \ core-ext,block-ext backslash |
' ( alias ( immediate |
\G Comment till the end of the line if @code{BLK} contains 0 (i.e., |
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\G while not loading a block), parse and discard the remainder of the |
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\G parse area. Otherwise, parse and discard all subsequent characters |
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\G in the parse area corresponding to the current line. |
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immediate |
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' ( alias ( ( compilation 'ccc<close-paren>' -- ; run-time -- ) \ core,file paren |
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\G Comment, usually till the next @code{)}: parse and discard all |
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\G subsequent characters in the parse area until ")" is |
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\G encountered. During interactive input, an end-of-line also acts as |
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\G a comment terminator. For file input, it does not; if the |
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\G end-of-file is encountered whilst parsing for the ")" delimiter, |
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\G Gforth will generate a warning. |
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immediate |
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forth definitions |
forth definitions |
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also locals-types |
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\ these "locals" are used for comparison in TO |
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c: some-clocal 2drop |
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d: some-dlocal 2drop |
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f: some-flocal 2drop |
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w: some-wlocal 2drop |
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\ the following gymnastics are for declaring locals without type specifier. |
\ the following gymnastics are for declaring locals without type specifier. |
\ we exploit a feature of our dictionary: every wordlist |
\ we exploit a feature of our dictionary: every wordlist |
\ has it's own methods for finding words etc. |
\ has it's own methods for finding words etc. |
\ So we create a vocabulary new-locals, that creates a 'w:' local named x |
\ So we create a vocabulary new-locals, that creates a 'w:' local named x |
\ when it is asked if it contains x. |
\ when it is asked if it contains x. |
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also locals-types |
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: new-locals-find ( caddr u w -- nfa ) |
: new-locals-find ( caddr u w -- nfa ) |
\ this is the find method of the new-locals vocabulary |
\ this is the find method of the new-locals vocabulary |
\ make a new local with name caddr u; w is ignored |
\ make a new local with name caddr u; w is ignored |
\ the returned nfa denotes a word that produces what W: produces |
\ the returned nfa denotes a word that produces what W: produces |
\ !! do the whole thing without nextname |
\ !! do the whole thing without nextname |
drop nextname |
drop nextname |
['] W: >name ; |
['] W: >head-noprim ; |
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previous |
previous |
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Line 255 previous
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Line 339 previous
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true abort" this should not happen: new-locals-reveal" ; |
true abort" this should not happen: new-locals-reveal" ; |
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create new-locals-map ( -- wordlist-map ) |
create new-locals-map ( -- wordlist-map ) |
' new-locals-find A, ' new-locals-reveal A, |
' new-locals-find A, |
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' new-locals-reveal A, |
vocabulary new-locals |
' drop A, \ rehash method |
new-locals-map ' new-locals >body cell+ A! \ !! use special access words |
' drop A, |
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new-locals-map mappedwordlist Constant new-locals-wl |
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\ slowvoc @ |
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\ slowvoc on |
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\ vocabulary new-locals |
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\ slowvoc ! |
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\ new-locals-map ' new-locals >body wordlist-map A! \ !! use special access words |
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variable old-dpp |
variable old-dpp |
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\ and now, finally, the user interface words |
\ and now, finally, the user interface words |
: { ( -- addr wid 0 ) \ gforth open-brace |
: { ( -- latestxt wid 0 ) \ gforth open-brace |
dp old-dpp ! |
dp old-dpp ! |
locals-dp dpp ! |
locals-dp dpp ! |
also new-locals |
latestxt get-current |
also get-current locals definitions locals-types |
get-order new-locals-wl swap 1+ set-order |
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also locals definitions locals-types |
0 TO locals-wordlist |
0 TO locals-wordlist |
0 postpone [ ; immediate |
0 postpone [ ; immediate |
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locals-types definitions |
locals-types definitions |
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: } ( addr wid 0 a-addr1 xt1 ... -- ) \ gforth close-brace |
: } ( latestxt wid 0 a-addr1 xt1 ... -- ) \ gforth close-brace |
\ ends locals definitions |
\ ends locals definitions |
] old-dpp @ dpp ! |
] old-dpp @ dpp ! |
begin |
begin |
Line 283 locals-types definitions
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Line 376 locals-types definitions
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repeat |
repeat |
drop |
drop |
locals-size @ alignlp-f locals-size ! \ the strictest alignment |
locals-size @ alignlp-f locals-size ! \ the strictest alignment |
set-current |
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previous previous |
previous previous |
locals-list TO locals-wordlist ; |
set-current lastcfa ! |
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locals-list 0 wordlist-id - TO locals-wordlist ; |
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: -- ( addr wid 0 ... -- ) \ gforth dash-dash |
: -- ( addr wid 0 ... -- ) \ gforth dash-dash |
} |
} |
Line 381 forth definitions
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Line 474 forth definitions
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\ If this assumption is too optimistic, the compiler will warn the user. |
\ If this assumption is too optimistic, the compiler will warn the user. |
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\ Implementation: migrated to kernal.fs |
\ Implementation: |
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\ THEN (another control flow from before joins the current one): |
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\ The new locals-list is the intersection of the current locals-list and |
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\ the orig-local-list. The new locals-size is the (alignment-adjusted) |
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\ size of the new locals-list. The following code is generated: |
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\ lp+!# (current-locals-size - orig-locals-size) |
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\ <then>: |
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\ lp+!# (orig-locals-size - new-locals-size) |
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\ Of course "lp+!# 0" is not generated. Still this is admittedly a bit |
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\ inefficient, e.g. if there is a locals declaration between IF and |
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\ ELSE. However, if ELSE generates an appropriate "lp+!#" before the |
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\ branch, there will be none after the target <then>. |
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\ explicit scoping |
\ explicit scoping |
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: scope ( compilation -- scope ; run-time -- ) \ gforth |
: scope ( compilation -- scope ; run-time -- ) \ gforth |
cs-push-part scopestart ; immediate |
cs-push-part scopestart ; immediate |
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: adjust-locals-list ( wid -- ) |
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locals-list @ common-list |
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dup list-size adjust-locals-size |
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locals-list ! ; |
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: endscope ( compilation scope -- ; run-time -- ) \ gforth |
: endscope ( compilation scope -- ; run-time -- ) \ gforth |
scope? |
scope? |
drop |
drop adjust-locals-list ; immediate |
locals-list @ common-list |
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dup list-size adjust-locals-size |
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locals-list ! ; immediate |
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\ adapt the hooks |
\ adapt the hooks |
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: locals-:-hook ( sys -- sys addr xt n ) |
: locals-:-hook ( sys -- sys addr xt n ) |
\ addr is the nfa of the defined word, xt its xt |
\ addr is the nfa of the defined word, xt its xt |
DEFERS :-hook |
DEFERS :-hook |
last @ lastcfa @ |
latest latestxt |
clear-leave-stack |
clear-leave-stack |
0 locals-size ! |
0 locals-size ! |
locals-buffer locals-dp ! |
locals-buffer locals-dp ! |
Line 428 forth definitions
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Line 510 forth definitions
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lastcfa ! last ! |
lastcfa ! last ! |
DEFERS ;-hook ; |
DEFERS ;-hook ; |
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\ THEN (another control flow from before joins the current one): |
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\ The new locals-list is the intersection of the current locals-list and |
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\ the orig-local-list. The new locals-size is the (alignment-adjusted) |
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\ size of the new locals-list. The following code is generated: |
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\ lp+!# (current-locals-size - orig-locals-size) |
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\ <then>: |
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\ lp+!# (orig-locals-size - new-locals-size) |
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\ Of course "lp+!# 0" is not generated. Still this is admittedly a bit |
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\ inefficient, e.g. if there is a locals declaration between IF and |
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\ ELSE. However, if ELSE generates an appropriate "lp+!#" before the |
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\ branch, there will be none after the target <then>. |
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: (then-like) ( orig -- ) |
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dead-orig = |
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if |
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>resolve drop |
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else |
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dead-code @ |
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if |
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>resolve set-locals-size-list dead-code off |
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else \ both live |
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over list-size adjust-locals-size |
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>resolve |
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adjust-locals-list |
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then |
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then ; |
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: (begin-like) ( -- ) |
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dead-code @ if |
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\ set up an assumption of the locals visible here. if the |
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\ users want something to be visible, they have to declare |
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\ that using ASSUME-LIVE |
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backedge-locals @ set-locals-size-list |
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then |
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dead-code off ; |
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\ AGAIN (the current control flow joins another, earlier one): |
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\ If the dest-locals-list is not a subset of the current locals-list, |
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\ issue a warning (see below). The following code is generated: |
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\ lp+!# (current-local-size - dest-locals-size) |
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\ branch <begin> |
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: (again-like) ( dest -- addr ) |
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over list-size adjust-locals-size |
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swap check-begin POSTPONE unreachable ; |
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\ UNTIL (the current control flow may join an earlier one or continue): |
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\ Similar to AGAIN. The new locals-list and locals-size are the current |
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\ ones. The following code is generated: |
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\ ?branch-lp+!# <begin> (current-local-size - dest-locals-size) |
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: (until-like) ( list addr xt1 xt2 -- ) |
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\ list and addr are a fragment of a cs-item |
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\ xt1 is the conditional branch without lp adjustment, xt2 is with |
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>r >r |
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locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment ) |
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r> drop r> compile, |
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swap <resolve ( list adjustment ) , |
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else ( list dest-addr adjustment ) |
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drop |
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r> compile, <resolve |
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r> drop |
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then ( list ) |
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check-begin ; |
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: (exit-like) ( -- ) |
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0 adjust-locals-size ; |
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' locals-:-hook IS :-hook |
' locals-:-hook IS :-hook |
' locals-;-hook IS ;-hook |
' locals-;-hook IS ;-hook |
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' (then-like) IS then-like |
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' (begin-like) IS begin-like |
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' (again-like) IS again-like |
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' (until-like) IS until-like |
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' (exit-like) IS exit-like |
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\ The words in the locals dictionary space are not deleted until the end |
\ The words in the locals dictionary space are not deleted until the end |
\ of the current word. This is a bit too conservative, but very simple. |
\ of the current word. This is a bit too conservative, but very simple. |
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Line 441 forth definitions
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Line 598 forth definitions
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\ things above are not control flow joins. Everything should be taken |
\ things above are not control flow joins. Everything should be taken |
\ over from the live flow. No lp+!# is generated. |
\ over from the live flow. No lp+!# is generated. |
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\ !! The lp gymnastics for UNTIL are also a real problem: locals cannot be |
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\ used in signal handlers (or anything else that may be called while |
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\ locals live beyond the lp) without changing the locals stack. |
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\ About warning against uses of dead locals. There are several options: |
\ About warning against uses of dead locals. There are several options: |
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\ 1) Do not complain (After all, this is Forth;-) |
\ 1) Do not complain (After all, this is Forth;-) |
Line 485 forth definitions
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Line 638 forth definitions
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2drop |
2drop |
endif ; |
endif ; |
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: >definer ( xt -- definer ) |
: >definer ( xt -- definer ) \ gforth |
\ this gives a unique identifier for the way the xt was defined |
\G @var{Definer} is a unique identifier for the way the @var{xt} |
\ words defined with different does>-codes have different definers |
\G was defined. Words defined with different @code{does>}-codes |
\ the definer can be used for comparison and in definer! |
\G have different definers. The definer can be used for |
dup >code-address [ ' spaces >code-address ] Literal = |
\G comparison and in @code{definer!}. |
\ !! this definition will not work on some implementations for `bits' |
dup >does-code |
if \ if >code-address delivers the same value for all does>-def'd words |
?dup-if |
>does-code 1 or \ bit 0 marks special treatment for does codes |
nip 1 or |
else |
else |
>code-address |
>code-address |
then ; |
then ; |
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: definer! ( definer xt -- ) |
: definer! ( definer xt -- ) \ gforth |
\ gives the word represented by xt the behaviour associated with definer |
\G The word represented by @var{xt} changes its behaviour to the |
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\G behaviour associated with @var{definer}. |
over 1 and if |
over 1 and if |
swap [ 1 invert ] literal and does-code! |
swap [ 1 invert ] literal and does-code! |
else |
else |
Line 506 forth definitions
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Line 660 forth definitions
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then ; |
then ; |
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:noname |
:noname |
' dup >definer [ ' locals-wordlist >definer ] literal = |
' dup >definer [ ' locals-wordlist ] literal >definer = |
if |
if |
>body ! |
>body ! |
else |
else |
-&32 throw |
-&32 throw |
endif ; |
endif ; |
:noname |
:noname |
0 0 0. 0.0e0 { c: clocal w: wlocal d: dlocal f: flocal } |
comp' drop dup >definer |
' dup >definer |
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case |
case |
[ ' locals-wordlist >definer ] literal \ value |
[ ' locals-wordlist ] literal >definer \ value |
OF >body POSTPONE Aliteral POSTPONE ! ENDOF |
OF >body POSTPONE Aliteral POSTPONE ! ENDOF |
[ ' clocal >definer ] literal |
\ !! dependent on c: etc. being does>-defining words |
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\ this works, because >definer uses >does-code in this case, |
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\ which produces a relocatable address |
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[ comp' some-clocal drop ] literal >definer |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE c! ENDOF |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE c! ENDOF |
[ ' wlocal >definer ] literal |
[ comp' some-wlocal drop ] literal >definer |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE ! ENDOF |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE ! ENDOF |
[ ' dlocal >definer ] literal |
[ comp' some-dlocal drop ] literal >definer |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE 2! ENDOF |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE 2! ENDOF |
[ ' flocal >definer ] literal |
[ comp' some-flocal drop ] literal >definer |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE f! ENDOF |
OF POSTPONE laddr# >body @ lp-offset, POSTPONE f! ENDOF |
-&32 throw |
-&32 throw |
endcase ; |
endcase ; |
special: TO ( c|w|d|r "name" -- ) \ core-ext,local |
interpret/compile: TO ( c|w|d|r "name" -- ) \ core-ext,local |
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: locals| |
: locals| |
\ don't use 'locals|'! use '{'! A portable and free '{' |
\ don't use 'locals|'! use '{'! A portable and free '{' |
\ implementation is compat/anslocals.fs |
\ implementation is compat/anslocals.fs |
BEGIN |
BEGIN |
name 2dup s" |" compare 0<> |
name 2dup s" |" str= 0= |
WHILE |
WHILE |
(local) |
(local) |
REPEAT |
REPEAT |