izaya/collapseos
1
0
Fork 0
mirror of https://github.com/hsoft/collapseos.git synced 2024-11-10 09:48:05 +11:00
Code Issues Releases Wiki Activity
11f8843a16
collapseos/blk/370

15 lines
427 B
Plaintext
Raw Normal View History

Make string length-prefixed instead of null-terminated I'm not sure why I chose null-terminated initially. Probably because the z80asm version had null-terminated strings. Length-prefixes strings are the traditional form of strings in Forth and it's a bit easier to work with them with traditional forth words when they're under this form.
2020-05-26 10:34:52 +10:00
: MOVE ( a1 a2 u -- )
MOVE: do not crash when u is 0 (#126) This commit adds ?DUP IF guards to MOVE and MOVE- that make them exit when u is 0. Without these guards a DO loop was executed 65535 times instead of 0. In particular, this fixes a crash when "105 LOAD I " is executed immediately after boot. Block editor word "I" passes IBUF length (0) to MOVE- and MOVE in this case, causing a crash.
2020-06-21 20:49:45 +10:00
?DUP IF ( u ) 0 DO ( a1 a2 )
Make string length-prefixed instead of null-terminated I'm not sure why I chose null-terminated initially. Probably because the z80asm version had null-terminated strings. Length-prefixes strings are the traditional form of strings in Forth and it's a bit easier to work with them with traditional forth words when they're under this form.
2020-05-26 10:34:52 +10:00
SWAP C@+ ( a2 a1+1 x )
ROT C!+ ( a1+1 a2+1 )
MOVE: do not crash when u is 0 (#126) This commit adds ?DUP IF guards to MOVE and MOVE- that make them exit when u is 0. Without these guards a DO loop was executed 65535 times instead of 0. In particular, this fixes a crash when "105 LOAD I " is executed immediately after boot. Block editor word "I" passes IBUF length (0) to MOVE- and MOVE in this case, causing a crash.
2020-06-21 20:49:45 +10:00
LOOP THEN 2DROP ;
Make string length-prefixed instead of null-terminated I'm not sure why I chose null-terminated initially. Probably because the z80asm version had null-terminated strings. Length-prefixes strings are the traditional form of strings in Forth and it's a bit easier to work with them with traditional forth words when they're under this form.
2020-05-26 10:34:52 +10:00
: MOVE- ( a1 a2 u -- )
MOVE: do not crash when u is 0 (#126) This commit adds ?DUP IF guards to MOVE and MOVE- that make them exit when u is 0. Without these guards a DO loop was executed 65535 times instead of 0. In particular, this fixes a crash when "105 LOAD I " is executed immediately after boot. Block editor word "I" passes IBUF length (0) to MOVE- and MOVE in this case, causing a crash.
2020-06-21 20:49:45 +10:00
?DUP IF TUCK + 1- ( a1 u a2+u-1 )
Make string length-prefixed instead of null-terminated I'm not sure why I chose null-terminated initially. Probably because the z80asm version had null-terminated strings. Length-prefixes strings are the traditional form of strings in Forth and it's a bit easier to work with them with traditional forth words when they're under this form.
2020-05-26 10:34:52 +10:00
ROT 2 PICK + 1- ( u a2+u-1 a1+u-1 )
ROT ( u ) 0 DO ( a2 a1 )
C@- ( a2 a1-1 x )
ROT C!- ( a1-1 a2-1 ) SWAP ( a2 a1 )
MOVE: do not crash when u is 0 (#126) This commit adds ?DUP IF guards to MOVE and MOVE- that make them exit when u is 0. Without these guards a DO loop was executed 65535 times instead of 0. In particular, this fixes a crash when "105 LOAD I " is executed immediately after boot. Block editor word "I" passes IBUF length (0) to MOVE- and MOVE in this case, causing a crash.
2020-06-21 20:49:45 +10:00
LOOP THEN 2DROP ;
Make string length-prefixed instead of null-terminated I'm not sure why I chose null-terminated initially. Probably because the z80asm version had null-terminated strings. Length-prefixes strings are the traditional form of strings in Forth and it's a bit easier to work with them with traditional forth words when they're under this form.
2020-05-26 10:34:52 +10:00
: MOVE, ( a u -- ) H@ OVER ALLOT SWAP MOVE ;
: PREV 3 - DUP @ - ;
Reference in New Issue Copy Permalink