version 1.1, 1994/05/07 14:55:56
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version 1.35, 1997/10/04 17:33:53
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\ A powerful locals implementation |
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\ Copyright (C) 1995 Free Software Foundation, Inc. |
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\ This file is part of Gforth. |
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\ Gforth is free software; you can redistribute it and/or |
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\ modify it under the terms of the GNU General Public License |
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\ as published by the Free Software Foundation; either version 2 |
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\ of the License, or (at your option) any later version. |
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\ This program is distributed in the hope that it will be useful, |
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\ but WITHOUT ANY WARRANTY; without even the implied warranty of |
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\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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\ GNU General Public License for more details. |
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\ You should have received a copy of the GNU General Public License |
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\ along with this program; if not, write to the Free Software |
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\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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\ More documentation can be found in the manual and in |
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\ http://www.complang.tuwien.ac.at/papers/ertl94l.ps.gz |
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\ Local variables are quite important for writing readable programs, but |
\ Local variables are quite important for writing readable programs, but |
\ IMO (anton) they are the worst part of the standard. There they are very |
\ IMO (anton) they are the worst part of the standard. There they are very |
\ restricted and have an ugly interface. |
\ restricted and have an ugly interface. |
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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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include float.fs |
require search.fs |
include search-order.fs |
require float.fs |
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: compile-@local ( n -- ) \ gforth compile-fetch-local |
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case |
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0 of postpone @local0 endof |
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1 cells of postpone @local1 endof |
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2 cells of postpone @local2 endof |
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3 cells of postpone @local3 endof |
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( otherwise ) dup postpone @local# , |
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endcase ; |
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: compile-f@local ( n -- ) \ gforth compile-f-fetch-local |
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case |
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0 of postpone f@local0 endof |
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1 floats of postpone f@local1 endof |
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( otherwise ) dup postpone f@local# , |
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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, |
Line 71 include search-order.fs
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Line 126 include search-order.fs
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\ lp must have the strictest alignment (usually float) across calls; |
\ lp must have the strictest alignment (usually float) across calls; |
\ for simplicity we align it strictly for every group. |
\ for simplicity we align it strictly for every group. |
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slowvoc @ |
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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 Constant locals-list \ acts like a variable that contains |
' locals >body ' locals-list >body ! |
\ a linear list of locals names |
slowvoc ! |
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create locals-buffer 1000 allot \ !! limited and unsafe |
create locals-buffer 1000 allot \ !! limited and unsafe |
\ here the names of the local variables are stored |
\ here the names of the local variables are stored |
Line 83 variable locals-dp \ so here's the speci
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Line 140 variable locals-dp \ so here's the speci
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: alignlp-w ( n1 -- n2 ) |
: alignlp-w ( n1 -- n2 ) |
\ cell-align size and generate the corresponding code for aligning lp |
\ cell-align size and generate the corresponding code for aligning lp |
dup aligned tuck - compile-lp+!# ; |
aligned dup adjust-locals-size ; |
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: alignlp-f ( n1 -- n2 ) |
: alignlp-f ( n1 -- n2 ) |
dup faligned tuck - compile-lp+!# ; |
faligned dup adjust-locals-size ; |
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\ a local declaration group (the braces stuff) is compiled by calling |
\ a local declaration group (the braces stuff) is compiled by calling |
\ the appropriate compile-pushlocal for the locals, starting with the |
\ the appropriate compile-pushlocal for the locals, starting with the |
Line 100 variable locals-dp \ so here's the speci
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Line 157 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 111 variable locals-dp \ so here's the speci
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Line 217 variable locals-dp \ so here's the speci
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postpone swap postpone >l postpone >l ; |
postpone swap postpone >l postpone >l ; |
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: compile-pushlocal-c ( a-addr -- ) ( run-time: w -- ) |
: compile-pushlocal-c ( a-addr -- ) ( run-time: w -- ) |
-1 chars compile-lp+!# |
-1 chars compile-lp+! |
locals-size @ swap ! |
locals-size @ swap ! |
postpone lp@ postpone c! ; |
postpone lp@ postpone c! ; |
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: create-local ( " name" -- a-addr ) |
: create-local ( " name" -- a-addr ) |
\ defines the local "name"; the offset of the local shall be stored in a-addr |
\ defines the local "name"; the offset of the local shall be |
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\ stored in a-addr |
create |
create |
immediate |
immediate restrict |
here 0 , ( place for the offset ) ; |
here 0 , ( place for the offset ) ; |
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: lp-offset ( n1 -- n2 ) |
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\ converts the offset from the frame start to an offset from lp and |
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\ i.e., the address of the local is lp+locals_size-offset |
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locals-size @ swap - ; |
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: lp-offset, ( n -- ) |
: lp-offset, ( n -- ) |
\ converts the offset from the frame start to an offset from lp and |
\ converts the offset from the frame start to an offset from lp and |
\ adds it as inline argument to a preceding locals primitive |
\ adds it as inline argument to a preceding locals primitive |
\ i.e., the address of the local is lp+locals_size-offset |
lp-offset , ; |
locals-size @ swap - , ; |
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vocabulary locals-types \ this contains all the type specifyers, -- and } |
vocabulary locals-types \ this contains all the type specifyers, -- and } |
locals-types definitions |
locals-types definitions |
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: W: |
: W: ( "name" -- a-addr xt ) \ gforth w-colon |
create-local ( "name" -- a-addr xt ) |
create-local |
\ xt produces the appropriate locals pushing code when executed |
\ xt produces the appropriate locals pushing code when executed |
['] compile-pushlocal-w |
['] compile-pushlocal-w |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
\ compiles a local variable access |
\ compiles a local variable access |
postpone @local# @ lp-offset, ; |
@ lp-offset compile-@local ; |
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: W^ |
: W^ ( "name" -- a-addr xt ) \ gforth w-caret |
create-local ( "name" -- a-addr xt ) |
create-local |
['] compile-pushlocal-w |
['] compile-pushlocal-w |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
postpone laddr# @ lp-offset, ; |
postpone laddr# @ lp-offset, ; |
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: F: |
: F: ( "name" -- a-addr xt ) \ gforth f-colon |
create-local ( "name" -- a-addr xt ) |
create-local |
['] compile-pushlocal-f |
['] compile-pushlocal-f |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
postpone f@local# @ lp-offset, ; |
@ lp-offset compile-f@local ; |
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: F^ |
: F^ ( "name" -- a-addr xt ) \ gforth f-caret |
create-local ( "name" -- a-addr xt ) |
create-local |
['] compile-pushlocal-f |
['] compile-pushlocal-f |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
postpone laddr# @ lp-offset, ; |
postpone laddr# @ lp-offset, ; |
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: D: |
: D: ( "name" -- a-addr xt ) \ gforth d-colon |
create-local ( "name" -- a-addr xt ) |
create-local |
['] compile-pushlocal-d |
['] compile-pushlocal-d |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
postpone laddr# @ lp-offset, postpone 2@ ; |
postpone laddr# @ lp-offset, postpone 2@ ; |
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: D^ |
: D^ ( "name" -- a-addr xt ) \ gforth d-caret |
create-local ( "name" -- a-addr xt ) |
create-local |
['] compile-pushlocal-d |
['] compile-pushlocal-d |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
postpone laddr# @ lp-offset, ; |
postpone laddr# @ lp-offset, ; |
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: C: |
: C: ( "name" -- a-addr xt ) \ gforth c-colon |
create-local ( "name" -- a-addr xt ) |
create-local |
['] compile-pushlocal-c |
['] compile-pushlocal-c |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
postpone laddr# @ lp-offset, postpone c@ ; |
postpone laddr# @ lp-offset, postpone c@ ; |
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: C^ |
: C^ ( "name" -- a-addr xt ) \ gforth c-caret |
create-local ( "name" -- a-addr xt ) |
create-local |
['] compile-pushlocal-c |
['] compile-pushlocal-c |
does> ( Compilation: -- ) ( Run-time: -- w ) |
does> ( Compilation: -- ) ( Run-time: -- w ) |
postpone laddr# @ lp-offset, ; |
postpone laddr# @ lp-offset, ; |
Line 192 forth definitions
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Line 303 forth definitions
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\ 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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0. 2constant last-local \ !! actually a 2value |
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also locals-types |
also locals-types |
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: new-locals-find ( caddr u w -- nfa ) |
: new-locals-find ( caddr u w -- nfa ) |
Line 201 also locals-types
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Line 310 also locals-types
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\ 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 W: \ we don't want the thing that W: produces, |
drop nextname |
['] last-local >body 2! \ but the nfa of a word that produces that value: last-local |
['] W: >name ; |
[ ' last-local >name ] Aliteral ; |
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previous |
previous |
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: new-locals-reveal ( -- ) |
: new-locals-reveal ( -- ) |
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 ' new-locals-find A, ' new-locals-reveal A, |
create new-locals-map ( -- wordlist-map ) |
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' new-locals-find A, |
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' new-locals-reveal A, |
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' drop A, \ rehash method |
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' drop A, |
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slowvoc @ |
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slowvoc on |
vocabulary new-locals |
vocabulary new-locals |
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slowvoc ! |
new-locals-map ' new-locals >body cell+ A! \ !! use special access words |
new-locals-map ' new-locals >body cell+ 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 ) |
: { ( -- lastxt wid 0 ) \ gforth open-brace |
dp old-dpp ! |
dp old-dpp ! |
locals-dp dpp ! |
locals-dp dpp ! |
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lastxt get-current |
also new-locals |
also new-locals |
also get-current locals definitions locals-types |
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 ... -- ) |
: } ( lastxt wid 0 a-addr1 xt1 ... -- ) \ gforth close-brace |
\ ends locals definitions |
\ ends locals definitions |
] old-dpp @ dpp ! |
] old-dpp @ dpp ! |
begin |
begin |
Line 238 locals-types definitions
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Line 354 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 |
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set-current lastcfa ! |
locals-list TO locals-wordlist ; |
locals-list TO locals-wordlist ; |
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: -- ( addr wid 0 ... -- ) |
: -- ( addr wid 0 ... -- ) \ gforth dash-dash |
} |
} |
[char] } word drop ; |
[char] } parse 2drop ; |
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forth definitions |
forth definitions |
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Line 338 forth definitions
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Line 454 forth definitions
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\ Implementation: |
\ Implementation: |
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\ orig, dest and do-sys have the following structure: |
\ explicit scoping |
\ address (of the branch or the instruction to be branched to) (TOS) |
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\ locals-list (valid at address) (second) |
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\ locals-size (at address; this could be computed from locals-list, but so what) (third) |
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3 constant cs-item-size |
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: CS-PICK ( ... u -- ... destu ) |
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1+ cs-item-size * 1- >r |
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r@ pick r@ pick r@ pick |
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rdrop ; |
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: CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu ) |
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1+ cs-item-size * 1- >r |
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r@ roll r@ roll r@ roll |
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rdrop ; |
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: CS-PUSH ( -- dest/orig ) |
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locals-size @ |
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locals-list @ |
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here ; |
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: BUT sys? 1 cs-roll ; immediate restrict |
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: YET sys? 0 cs-pick ; immediate restrict |
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: common-list ( list1 list2 -- list3 ) |
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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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endif |
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@ |
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repeat |
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drop ; |
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: sub-list? ( list1 list2 -- f ) |
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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 ) |
: scope ( compilation -- scope ; run-time -- ) \ gforth |
\ size of the locals frame represented by list |
cs-push-part scopestart ; immediate |
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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cell+ 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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: x>mark ( -- orig ) |
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cs-push 0 , ; |
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variable dead-code \ true if normal code at "here" would be dead |
: endscope ( compilation scope -- ; run-time -- ) \ gforth |
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scope? |
: unreachable ( -- ) |
drop |
\ declares the current point of execution as unreachable and |
locals-list @ common-list |
\ prepares the assumptions for a possible upcoming BEGIN |
dup list-size adjust-locals-size |
dead-code on |
locals-list ! ; immediate |
dup 0<> if |
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2 pick 2 pick |
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else |
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0 0 |
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endif |
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locals-list ! |
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locals-size ! ; |
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: check-begin ( list -- ) |
\ adapt the hooks |
\ 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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endif ; |
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: xahead ( -- orig ) |
: locals-:-hook ( sys -- sys addr xt n ) |
POSTPONE branch x>mark unreachable ; immediate |
\ addr is the nfa of the defined word, xt its xt |
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DEFERS :-hook |
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last @ lastcfa @ |
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clear-leave-stack |
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0 locals-size ! |
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locals-buffer locals-dp ! |
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0 locals-list ! |
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dead-code off |
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defstart ; |
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: xif ( -- orig ) |
: locals-;-hook ( sys addr xt sys -- sys ) |
POSTPONE ?branch x>mark ; immediate |
def? |
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0 TO locals-wordlist |
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0 adjust-locals-size ( not every def ends with an exit ) |
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lastcfa ! last ! |
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DEFERS ;-hook ; |
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\ THEN (another control flow from before joins the current one): |
\ THEN (another control flow from before joins the current one): |
\ The new locals-list is the intersection of the current locals-list and |
\ The new locals-list is the intersection of the current locals-list and |
Line 441 variable dead-code \ true if normal code
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Line 498 variable dead-code \ true if normal code
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\ inefficient, e.g. if there is a locals declaration between IF and |
\ inefficient, e.g. if there is a locals declaration between IF and |
\ ELSE. However, if ELSE generates an appropriate "lp+!#" before the |
\ ELSE. However, if ELSE generates an appropriate "lp+!#" before the |
\ branch, there will be none after the target <then>. |
\ branch, there will be none after the target <then>. |
: xthen ( orig -- ) |
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sys? dup @ ?struc |
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dead-code @ |
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if |
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>resolve |
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locals-list ! |
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locals-size ! |
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else |
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locals-size @ 3 roll - compile-lp+!# |
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>resolve |
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locals-list @ common-list locals-list ! |
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locals-size @ locals-list @ list-size - compile-lp+!# |
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endif |
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dead-code off ; immediate |
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: scope ( -- dest ) |
: (then-like) ( orig -- ) |
cs-push ; immediate |
dead-orig = |
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if |
: endscope ( dest -- ) |
>resolve drop |
drop |
else |
locals-list @ common-list locals-list ! |
dead-code @ |
locals-size @ locals-list @ list-size - compile-lp+!# |
if |
drop ; immediate |
>resolve set-locals-size-list dead-code off |
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else \ both live |
: xexit ( -- ) |
over list-size adjust-locals-size |
locals-size @ compile-lp+!# POSTPONE exit unreachable ; immediate |
>resolve |
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locals-list @ common-list dup list-size adjust-locals-size |
: x?exit ( -- ) |
locals-list ! |
POSTPONE xif POSTPONE xexit POSTPONE xthen ; immediate |
then |
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then ; |
: xelse ( orig1 -- orig2 ) |
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sys? |
: (begin-like) ( -- ) |
POSTPONE xahead |
dead-code @ if |
1 cs-roll |
\ set up an assumption of the locals visible here. if the |
POSTPONE xthen ; immediate |
\ users want something to be visible, they have to declare |
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\ that using ASSUME-LIVE |
: xbegin ( -- dest ) |
backedge-locals @ set-locals-size-list |
cs-push dead-code off ; immediate |
then |
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dead-code off ; |
: xwhile ( dest -- orig dest ) |
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sys? |
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POSTPONE xif |
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1 cs-roll ; immediate |
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\ AGAIN (the current control flow joins another, earlier one): |
\ AGAIN (the current control flow joins another, earlier one): |
\ If the dest-locals-list is not a subset of the current locals-list, |
\ If the dest-locals-list is not a subset of the current locals-list, |
\ issue a warning (see below). The following code is generated: |
\ issue a warning (see below). The following code is generated: |
\ lp+!# (current-local-size - dest-locals-size) |
\ lp+!# (current-local-size - dest-locals-size) |
\ branch <begin> |
\ branch <begin> |
: xagain ( dest -- ) |
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sys? |
: (again-like) ( dest -- addr ) |
locals-size @ 3 roll - compile-lp+!# |
over list-size adjust-locals-size |
POSTPONE branch |
swap check-begin POSTPONE unreachable ; |
<resolve |
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check-begin |
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unreachable ; immediate |
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\ UNTIL (the current control flow may join an earlier one or continue): |
\ UNTIL (the current control flow may join an earlier one or continue): |
\ Similar to AGAIN. The new locals-list and locals-size are the current |
\ Similar to AGAIN. The new locals-list and locals-size are the current |
\ ones. The following code is generated: |
\ ones. The following code is generated: |
\ lp+!# (current-local-size - dest-locals-size) |
\ ?branch-lp+!# <begin> (current-local-size - dest-locals-size) |
\ ?branch <begin> |
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\ lp+!# (dest-local-size - current-locals-size) |
|
\ (Another inefficiency. Maybe we should introduce a ?branch-lp+!# |
|
\ primitive. This would also solve the interrupt problem) |
|
: until-like ( dest xt -- ) |
|
>r |
|
sys? |
|
locals-size @ dup 4 roll - compile-lp+!# ( list dest-addr old-locals-size ) |
|
r> compile, |
|
>r <resolve |
|
check-begin |
|
locals-size @ r> - compile-lp+!# ; |
|
|
|
: xuntil ( dest -- ) |
|
['] ?branch until-like ; immediate |
|
|
|
: xrepeat ( orig dest -- ) |
|
3 pick 0= ?struc |
|
postpone xagain |
|
postpone xthen ; immediate |
|
|
|
\ counted loops |
|
|
|
\ leave poses a little problem here |
|
\ we have to store more than just the address of the branch, so the |
|
\ traditional linked list approach is no longer viable. |
|
\ This is solved by storing the information about the leavings in a |
|
\ special stack. The leavings of different DO-LOOPs are separated |
|
\ by a 0 entry |
|
|
|
\ !! remove the fixed size limit. 'Tis easy. |
|
20 constant leave-stack-size |
|
create leave-stack leave-stack-size cs-item-size * cells allot |
|
variable leave-sp leave-stack leave-sp ! |
|
|
|
: clear-leave-stack ( -- ) |
|
leave-stack leave-sp ! ; |
|
|
|
\ : leave-empty? ( -- f ) |
|
\ leave-sp @ leave-stack = ; |
|
|
|
: >leave ( orig -- ) |
|
\ push on leave-stack |
|
leave-sp @ |
|
dup [ leave-stack leave-stack-size cs-item-size * cells + ] Aliteral >= |
|
if |
|
abort" leave-stack full" |
|
endif |
|
tuck ! cell+ |
|
tuck ! cell+ |
|
tuck ! cell+ |
|
leave-sp ! ; |
|
|
|
: leave> ( -- orig ) |
|
\ pop from leave-stack |
|
leave-sp @ |
|
dup leave-stack <= if |
|
abort" leave-stack empty" |
|
endif |
|
cell - dup @ swap |
|
cell - dup @ swap |
|
cell - dup @ swap |
|
leave-sp ! ; |
|
|
|
: done ( -- ) |
|
\ !! the original done had ( addr -- ) |
|
begin |
|
leave> |
|
dup |
|
while |
|
POSTPONE xthen |
|
repeat |
|
2drop drop ; immediate |
|
|
|
: xleave ( -- ) |
|
POSTPONE xahead |
|
>leave ; immediate |
|
|
|
: x?leave ( -- ) |
|
POSTPONE 0= POSTPONE xif |
|
>leave ; immediate |
|
|
|
: xdo ( -- do-sys ) |
|
POSTPONE (do) |
|
POSTPONE xbegin |
|
0 0 0 >leave ; immediate |
|
|
|
: x?do ( -- do-sys ) |
|
0 0 0 >leave |
|
POSTPONE (?do) |
|
x>mark >leave |
|
POSTPONE xbegin ; immediate |
|
|
|
: xfor ( -- do-sys ) |
|
POSTPONE (for) |
|
POSTPONE xbegin |
|
0 0 0 >leave ; immediate |
|
|
|
\ LOOP etc. are just like UNTIL |
: (until-like) ( list addr xt1 xt2 -- ) |
\ the generated code for ?DO ... LOOP with locals is inefficient, this |
\ list and addr are a fragment of a cs-item |
\ could be changed by introducing (loop)-lp+!# etc. |
\ xt1 is the conditional branch without lp adjustment, xt2 is with |
|
>r >r |
|
locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment ) |
|
r> drop r> compile, |
|
swap <resolve ( list adjustment ) , |
|
else ( list dest-addr adjustment ) |
|
drop |
|
r> compile, <resolve |
|
r> drop |
|
then ( list ) |
|
check-begin ; |
|
|
: loop-like ( do-sys xt -- ) |
: (exit-like) ( -- ) |
until-like POSTPONE done POSTPONE unloop ; |
0 adjust-locals-size ; |
|
|
: xloop ( do-sys -- ) |
|
['] (loop) loop-like ; immediate |
|
|
|
: x+loop ( do-sys -- ) |
|
['] (+loop) loop-like ; immediate |
|
|
|
: xs+loop ( do-sys -- ) |
|
['] (s+loop) loop-like ; immediate |
|
|
|
: locals-:-hook ( sys -- sys addr xt ) |
|
DEFERS :-hook |
|
last @ lastcfa @ |
|
clear-leave-stack |
|
0 locals-size ! |
|
locals-buffer locals-dp ! |
|
0 locals-list ! ; ( clear locals vocabulary ) |
|
|
|
: locals-;-hook ( sys addr xt -- sys ) |
|
0 TO locals-wordlist |
|
locals-size @ compile-lp+!# |
|
lastcfa ! last ! |
|
DEFERS ;-hook ; |
|
|
|
' locals-:-hook IS :-hook |
' locals-:-hook IS :-hook |
' locals-;-hook IS ;-hook |
' locals-;-hook IS ;-hook |
|
|
|
' (then-like) IS then-like |
|
' (begin-like) IS begin-like |
|
' (again-like) IS again-like |
|
' (until-like) IS until-like |
|
' (exit-like) IS exit-like |
|
|
\ 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. |
|
|
Line 643 variable leave-sp leave-stack leave-sp
|
Line 575 variable leave-sp leave-stack leave-sp
|
\ 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. |
|
|
\ !! The lp gymnastics for UNTIL are also a real problem: locals cannot be |
|
\ used in signal handlers (or anything else that may be called while |
|
\ locals live beyond the lp) without changing the locals stack. |
|
|
|
\ About warning against uses of dead locals. There are several options: |
\ About warning against uses of dead locals. There are several options: |
|
|
\ 1) Do not complain (After all, this is Forth;-) |
\ 1) Do not complain (After all, this is Forth;-) |
Line 676 variable leave-sp leave-stack leave-sp
|
Line 604 variable leave-sp leave-stack leave-sp
|
|
|
\ And here's finally the ANS standard stuff |
\ And here's finally the ANS standard stuff |
|
|
: (local) ( addr u -- ) |
: (local) ( addr u -- ) \ local paren-local-paren |
\ a little space-inefficient, but well deserved ;-) |
\ a little space-inefficient, but well deserved ;-) |
\ In exchange, there are no restrictions whatsoever on using (local) |
\ In exchange, there are no restrictions whatsoever on using (local) |
dup |
\ as long as you use it in a definition |
if |
dup |
nextname POSTPONE { [ also locals-types ] W: } [ previous ] |
if |
else |
nextname POSTPONE { [ also locals-types ] W: } [ previous ] |
2drop |
else |
endif ; |
2drop |
|
endif ; |
\ \ !! untested |
|
\ : TO ( c|w|d|r "name" -- ) |
: >definer ( xt -- definer ) |
\ \ !! state smart |
\ this gives a unique identifier for the way the xt was defined |
\ 0 0 0. 0.0e0 { c: clocal w: wlocal d: dlocal f: flocal } |
\ words defined with different does>-codes have different definers |
\ ' dup >definer |
\ the definer can be used for comparison and in definer! |
\ state @ |
dup >does-code |
\ if |
?dup-if |
\ case |
nip 1 or |
\ [ ' locals-wordlist >definer ] literal \ value |
else |
\ OF >body POSTPONE Aliteral POSTPONE ! ENDOF |
>code-address |
\ [ ' clocal >definer ] literal |
then ; |
\ OF POSTPONE laddr# >body @ lp-offset, POSTPONE c! ENDOF |
|
\ [ ' wlocal >definer ] literal |
: definer! ( definer xt -- ) |
\ OF POSTPONE laddr# >body @ lp-offset, POSTPONE ! ENDOF |
\ gives the word represented by xt the behaviour associated with definer |
\ [ ' dlocal >definer ] literal |
over 1 and if |
\ OF POSTPONE laddr# >body @ lp-offset, POSTPONE d! ENDOF |
swap [ 1 invert ] literal and does-code! |
\ [ ' flocal >definer ] literal |
else |
\ OF POSTPONE laddr# >body @ lp-offset, POSTPONE f! ENDOF |
code-address! |
\ abort" can only store TO value or local value" |
then ; |
\ endcase |
|
\ else |
:noname |
\ [ ' locals-wordlist >definer ] literal = |
' dup >definer [ ' locals-wordlist ] literal >definer = |
\ if |
if |
\ >body ! |
>body ! |
\ else |
else |
\ abort" can only store TO value" |
-&32 throw |
\ endif |
endif ; |
\ endif ; |
:noname |
|
0 0 0. 0.0e0 { c: clocal w: wlocal d: dlocal f: flocal } |
\ : locals| |
comp' drop dup >definer |
\ !! should lie around somewhere |
case |
|
[ ' locals-wordlist ] literal >definer \ value |
|
OF >body POSTPONE Aliteral POSTPONE ! ENDOF |
|
\ !! dependent on c: etc. being does>-defining words |
|
\ this works, because >definer uses >does-code in this case, |
|
\ which produces a relocatable address |
|
[ comp' clocal drop >definer ] literal |
|
OF POSTPONE laddr# >body @ lp-offset, POSTPONE c! ENDOF |
|
[ comp' wlocal drop >definer ] literal |
|
OF POSTPONE laddr# >body @ lp-offset, POSTPONE ! ENDOF |
|
[ comp' dlocal drop >definer ] literal |
|
OF POSTPONE laddr# >body @ lp-offset, POSTPONE 2! ENDOF |
|
[ comp' flocal drop >definer ] literal |
|
OF POSTPONE laddr# >body @ lp-offset, POSTPONE f! ENDOF |
|
-&32 throw |
|
endcase ; |
|
interpret/compile: TO ( c|w|d|r "name" -- ) \ core-ext,local |
|
|
|
: locals| |
|
\ don't use 'locals|'! use '{'! A portable and free '{' |
|
\ implementation is compat/anslocals.fs |
|
BEGIN |
|
name 2dup s" |" compare 0<> |
|
WHILE |
|
(local) |
|
REPEAT |
|
drop 0 (local) ; immediate restrict |