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get regex searching working

This commit is contained in:
~d6 2022-02-19 01:23:39 -05:00
parent de85141c84
commit 21a31755b6
2 changed files with 38 additions and 8 deletions
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8
grep.tal
View File

@ -3,7 +3,7 @@
( by d_m )
( print a character to STDOUT )
%emit { #18 DEO }
%emitt { #18 DEO }
( the first argument to grep is the regex )
( arguments are passed on STDIN, so we just )
@ -18,8 +18,8 @@
@println ( s* -> )
&loop LDAk #00 EQU ,&eof JCN ( did we reach \0 ? )
LDAk emit INC2 ,&loop JMP ( no so emit a char and repeat )
&eof #0a emit POP2 JMP2r ( yes so emit \n and return )
LDAk emitt INC2 ,&loop JMP ( no so emit a char and repeat )
&eof #0a emitt POP2 JMP2r ( yes so emit \n and return )
@r-read-stdin ( -> )
#12 DEI #0a EQU ,&execute JCN ( did we read \n ? )
@ -34,7 +34,7 @@
,&need-regex JCN ( jump if unset )
( regex is set )
;buffer ;regex LDA2 ;match JSR2 ( match regex )
;buffer ;regex LDA2 ;search JSR2 ( search line for a regex match )
#00 EQU ,&no-match JCN ( did we match? )
;buffer ;println JSR2 ( print any match )
&no-match BRK ( return )

38
regex.tal
View File

@ -35,6 +35,14 @@
%newline { #0a emit }
%quit! { #01 #0f DEO BRK }
( now that uxnasm throws errors about writing into the zero page )
( we have to do something like this to be able to compile library )
( code. we have to guess what offset to use since it needs to )
( avoid conficting with the program we're included in. )
( )
( remove this if needed when including it in other projects. )
|2000
( ERROR HANDLING )
( using error! will print the given message before causing )
@ -66,9 +74,24 @@
( )
( returns true if the string, and false otherwise. )
@match ( str* regex* -> bool^ )
#00 ;search-mode STA
;reset-stack JSR2
;loop JMP2
( )
@search ( str* regex* -> bool^ )
#01 ;search-mode STA STH2 ( s* [r*] )
&loop LDAk #00 EQU ,&eof JCN ( s* [r*] )
;reset-stack JSR2 ( s* [r*] )
DUP2 ;search-start STA2 ( s* [r*] )
DUP2 STH2kr ;loop JSR2 ( s* b^ [r*] )
,&found JCN ( s* [r*] )
INC2 ,&loop JMP ( s+1* [r*] )
&found POP2 POP2r #01 JMP2r ( 01 )
&eof ;reset-stack JSR2 ( s* [r*] )
DUP2 ;search-start STA2 ( s* [r*] )
STH2r ;loop JMP2 ( b^ )
( loop used during matching )
( )
( we don't use the return stack here since that )
@ -95,9 +118,11 @@
( follow the given address (next*) to continue matching )
@goto-next ( str* next* -> bool^ )
DUP2 #0000 GTH2 ,&has-next JCN
POP2 LDA null? ,&end-of-string JCN
;goto-backtrack JMP2
&end-of-string #01 JMP2r
POP2 LDAk null? ,&end-of-string JCN
;search-mode LDA ,&end-of-search JCN
POP2 ;goto-backtrack JMP2
&end-of-search DUP2 ;search-end STA2
&end-of-string POP2 #01 JMP2r
&has-next ;loop JMP2
( handle the empty node -- just follow the next pointer )
@ -133,6 +158,11 @@
( REGEX PARSING )
( are we in searching mode? )
@search-mode $1
@search-start $2
@search-end $2
( track the position in the input string )
@pos $2
@ -589,4 +619,4 @@
&above POPr POP &below #00 JMP2r
@iv-find ( c^ iv* -> bool^ )
)
)