mirror of https://github.com/hsoft/collapseos.git
Virgil Dupras
parent
b4f3fde062
commit
f8b7a3ce65
10
blk.fs
10
blk.fs
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@ -1123,7 +1123,7 @@ lblexec BSET L1 FSET ( B284 ) L2 FSET ( B286 )
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A ORr, IFZ, JP(HL), THEN,
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A DECr, ( compiled? ) IFNZ, ( no )
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3 CPi, IFZ, ( alias ) LDDE(HL), JR, lblexec BWR THEN,
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IFNC, ( switch )
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IFNC, ( ialias )
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LDDE(HL), EXDEHL, LDDE(HL), JR, lblexec BWR THEN,
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( cell or does. push PFA ) HL PUSH,
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A DECr, JRZ, lblnext BWR ( cell )
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@ -1739,7 +1739,7 @@ with "390 LOAD"
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( ----- 355 )
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: +! TUCK @ + SWAP ! ;
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: *! ( addr alias -- ) 1+ ! ;
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: **! ( addr switch -- ) 1+ @ ! ;
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: **! ( addr ialias -- ) 1+ @ ! ;
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: / /MOD NIP ;
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: MOD /MOD DROP ;
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: ALLOT HERE +! ;
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@ -2155,7 +2155,7 @@ XCURRENT @ _xapply ORG @ 0x04 ( stable ABI BOOT ) + !
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( ----- 391 )
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( Now we have "as late as possible" stuff. See bootstrap doc. )
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: :* ( addr -- ) (entry) 4 ( alias ) C, , ;
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: :** ( addr -- ) (entry) 5 ( switch ) C, , ;
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: :** ( addr -- ) (entry) 5 ( ialias ) C, , ;
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( ----- 392 )
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: _bchk DUP 0x7f + 0xff > IF LIT" br ovfl" (print) ABORT THEN ;
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: DO COMPILE 2>R H@ ; IMMEDIATE
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@ -2599,8 +2599,8 @@ lblexec BSET ( DI -> wordref )
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DI PUSHx, JMPs, lblnext @ RPCs, THEN,
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AL DECr, IFZ, ( does )
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DI PUSHx, DI INCx, DI INCx, DI [DI] MOVx[], THEN,
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( alias or switch ) DI [DI] MOVx[],
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AL DECr, IFNZ, ( switch ) DI [DI] MOVx[], THEN,
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( alias or ialias ) DI [DI] MOVx[],
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AL DECr, IFNZ, ( ialias ) DI [DI] MOVx[], THEN,
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JMPs, lblexec @ RPCs,
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THEN, ( continue to compiled )
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BP INCx, BP INCx, [BP] 0 DX MOV[]+x, ( pushRS )
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@ -66,7 +66,7 @@ WORD( a -- a Get wordref's beginning addr.
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: x ... ; -- Define a new word
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:* x a -- Define a new alias
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:** x a -- Define a new switch
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:** x a -- Define a new ialias
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CREATE x -- Create cell named x. Doesn't allocate a PF.
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[COMPILE] x -- *I* Compile word x and write it to HERE.
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IMMEDIATE words are *not* executed.
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@ -164,7 +164,7 @@ C! c a -- Store byte c in address a
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C!+ c a -- a+1 Store byte c in a and inc a.
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C!- c a -- a-1 Store byte c in a and dec a.
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*! a al -- Change alias al's addr to a.
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**! a sw -- Change switch sw's addr to a.
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**! a sw -- Change ialias sw's addr to a.
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CURRENT -- a Set a to wordref of last added entry.
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CURRENT* -- a A pointer to active CURRENT*. Useful
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when we have multiple active dicts.
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@ -185,7 +185,7 @@ MOVEW notes: this word's purpose is to interface with word-
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based systems. src and dst are addressed as *bytes* but u is a
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*word* count. Every iteration increases src and dst by 2. This
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shouldn't be used on regular memory, it will yield weird
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results. Use it with A! switch pointing to a word-based target.
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results. Use it with A! ialias pointing to a word-based target.
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# Arithmetic / Bits
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@ -109,7 +109,7 @@ compiled word.
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4: alias. See usage.txt. PFA is like a cell, but instead of
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pushing it to PS, we execute it.
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5: switch. Same as alias, but with an added indirection.
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5: ialias. Same as alias, but with an added indirection.
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# System variables
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@ -52,7 +52,7 @@ Interpreter output is unbuffered and only has EMIT. This
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word can also be overriden, mostly as a companion to the
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raison d'etre of your KEY override.
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# Aliases and Switches
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# Aliases
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A common pattern in Forth is to add an indirection layer with
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a pointer word. For example, if you have a word "FOO" for
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@ -65,7 +65,7 @@ verbose, which make us want to avoid this pattern for words
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that are often used.
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For this purpose, Collapse OS has two special word types:
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alias and switches.
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alias and ialiases (indirect alias).
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An alias is a variable that contains a pointer to another word.
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When invoked, we invoke the specified pointer with minimal over-
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@ -74,18 +74,18 @@ with "' _FOO :* FOO". Invoking FOO will then invoke "_FOO". You
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can change the alias' pointer with "*!" like this:
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"' BAR ' FOO *!". FOO now invokes BAR.
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A switch is like an alias, but with a second level of indi-
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A ialias is like an alias, but with a second level of indi-
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rection. The variable points to a cell pointing to our word.
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It works like an alias, except you have to use ":**" and "**!".
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Switches are used by core code which point to hardcoded
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Ialiases are used by core code which point to hardcoded
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addresses in RAM (because the core code is designed to run from
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ROM, we can't have regular variables). You are unlikely to
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need switches in regular code.
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need ialiases in regular code.
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# Addressed devices
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A@, A! and A, are the indirect versions of C@, C! and C,. They
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are switch words and initially point to C@, C! and C,.
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are ialias words and initially point to C@, C! and C,.
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Addressed device words can be useful to "pipe" processing to
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places outside of regular memory.
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