diff options
| author | Jacques Comeaux <jacquesrcomeaux@gmail.com> | 2022-08-20 15:57:06 -0500 |
|---|---|---|
| committer | Jacques Comeaux <jacquesrcomeaux@gmail.com> | 2022-08-20 15:57:06 -0500 |
| commit | ef373cb4047e51381819b1ffe5385fa8d2edcc7f (patch) | |
| tree | 14ab211b099c3f27f8035de61ff35d4b65454d21 /print.s | |
| parent | ac8d628827aa1cdf746fce8b4cdce140558e0f89 (diff) | |
Add S-Exp printer
Diffstat (limited to 'print.s')
| -rw-r--r-- | print.s | 73 |
1 files changed, 62 insertions, 11 deletions
@@ -1,11 +1,62 @@ - MOV R1, -(SP) - BR 20$ -10$: - TSTB @#177564 - BEQ 10$ - MOVB R1, @#177566 -20$: - MOVB (R0)+, R1 - BNE 10$ - MOV (SP)+, R1 - RTS PC +print: +004000 012705 MOV #6000, R5 ; store print buffer address in R5 +004002 006000 +004004 032700 BIT #1, R0 ; test if sexp is cons or atom +004006 000001 +004010 001003 BNE 6 +004012 004727 JSR PC, #handle_cons +004014 004100 +004016 000402 BR 4 +004020 004727 JSR PC, #handle_atom +004022 004200 +004024 012725 MOV #"\n\0", (R5)+ ; move newline and null byte into print buffer +004026 000012 +004030 000127 JMP #print_buffer +004032 004300 + +handle_cons: +004100 016046 MOV 2(R0), -(SP) ; push cdr onto stack +004102 000002 +004104 011000 MOV @R0, R0 ; traverse to car +004106 032700 BIT #1, R0 ; test if car is cons or atom +004110 000001 +004112 001005 BNE 12 +004114 112725 MOVB #"(", (R5)+ ; if cons output open paren +004116 000050 +004120 004727 JSR PC, #handle_cons ; recurse +004122 004100 +004124 000402 BR 4 +004126 004727 JSR PC, #handle_atom ; if atom output atom +004130 004200 +004132 012600 MOV (SP)+, R0 ; pop cdr from stack +004134 032700 BIT #1, R0 ; test if cdr is cons or atom +004136 001005 BNE 12 +004140 112725 MOVB #" ", (R5)+ ; if cons output space +004142 000040 +004144 004727 JSR PC, #handle_cons ; recurse +004156 004100 +004150 000402 BR 4 +004152 112725 MOVB #")", (R5)+ ; if atom output close paren +004154 000051 +004156 000207 RTS PC + +handle_atom: +004200 000401 BR 2 ; +004202 110125 MOVB R1, (R5)+ ; move char to print buffer +004204 112001 MOVB (R0)+, R1 ; get next byte +004206 001372 BNE -6 ; if not null continue +004210 000207 RTS PC ; + +print_buffer: +004300 012705 MOV #6000, R5 ; restore print buffer pointer +004302 006000 +004304 000404 BR 12 +004306 105737 TSTB @#177564 ; test if console ready +004310 177564 +004312 001772 BEQ -6 ; loop while not ready +004314 110137 MOVB R1, @#177566 ; send char to console +004316 177566 +004320 112501 MOVB (R5)+, R1 ; get next byte +004322 001362 BNE -16 ; if not null continue +004324 000127 JMP #read (002000) +004326 002000 |