mirror of https://git.sr.ht/~rabbits/uxn
75 lines
1.6 KiB
Tal
75 lines
1.6 KiB
Tal
( brainfuck interpreter )
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%DEC { #01 SUB }
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%DEC2 { #0001 SUB2 }
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%DECr { LITr 01 SUBr }
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%HALT { #0101 #0e DEO2 }
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%EMIT { #18 DEO }
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|0100 ( -> )
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;memory
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;program
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&while
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( Move the pointer to the right )
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LDAk LIT '> NEQ ,&movr JCN [ SWP2 INC2 SWP2 ] &movr
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( Move the pointer to the left )
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LDAk LIT '< NEQ ,&movl JCN [ SWP2 DEC2 SWP2 ] &movl
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( Increment the memory cell at the pointer )
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LDAk LIT '+ NEQ ,&incr JCN [ OVR2 STH2k LDA INC STH2r STA ] &incr
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( Decrement the memory cell at the pointer )
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LDAk LIT '- NEQ ,&decr JCN [ OVR2 STH2k LDA DEC STH2r STA ] &decr
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( Output the character signified by the cell at the pointer )
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LDAk LIT '. NEQ ,&emit JCN [ OVR2 LDA EMIT ] &emit
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( Jump past the matching ] if the cell at the pointer is 0 )
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LDAk LIT '[ NEQ ,&next JCN [ ,goto-next JSR ] &next
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( Jump back to the matching [ if the cell at the pointer is nonzero )
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LDAk LIT '] NEQ ,&prev JCN [ ,goto-back JSR ] &prev
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INC2 LDAk ,&while JCN
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POP2
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HALT
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BRK
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@goto-next ( -- )
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OVR2 LDA #00 EQU JMP JMP2r
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( depth ) LITr 00
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INC2
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&loop
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LDAk LIT '[ NEQ JMP INCr
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LDAk LIT '] NEQ ,&no-end JCN
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STHkr #00 EQU ,&end JCN
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DECr
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&no-end
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INC2 LDAk ,&loop JCN
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&end
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( depth ) POPr
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JMP2r
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@goto-back ( -- )
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OVR2 LDA #00 NEQ JMP JMP2r
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( depth ) LITr 00
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DEC2
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&loop
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LDAk LIT '] NEQ JMP INCr
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LDAk LIT '[ NEQ ,&no-end JCN
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STHkr #00 EQU ,&end JCN
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DECr
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&no-end
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DEC2 LDAk ,&loop JCN
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&end
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( depth ) POPr
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JMP2r
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@program ( Hello World! )
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"++++++++[>++++[>++>+++>+++>+<<<<
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"-]>+>+>->>+[<]<-]>>.>---.+++++++
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"..+++.>>.<-.<.+++.------.-------
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"-.>>+.>++. $1
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@memory |