diff --git a/mixed_case_keywords_mod.txt b/mixed_case_keywords_mod.txt new file mode 100644 index 0000000..06b142a --- /dev/null +++ b/mixed_case_keywords_mod.txt @@ -0,0 +1,195 @@ +Tokenizer mixed case keyword recognition + +This modification is based on a patch by user ArnoldLayne of the 6502.org +forum: http://forum.6502.org/viewtopic.php?f=5&t=4383 + +In EhBasic keywords must be upper case. This may be inconvenient on computers +with mixed case support. The modification below changes the tokenizer to match +lower, upper or even mixed case keywords. However, the listing will still show +keywords in upper case. + +; crunch keywords into Basic tokens +; position independent buffer version .. +; faster, dictionary search version .... + +LAB_13A6 + LDY #$FF ; set save index (makes for easy math later) + + SEC ; set carry for subtract + LDA Bpntrl ; get basic execute pointer low byte + SBC #= go save byte then continue crunching + + CMP #'<' ; compare with "<" + BCS LAB_13CC ; if >= go crunch now + + CMP #'0' ; compare with "0" + BCS LAB_13EC ; if >= go save byte then continue crunching + + STA Scnquo ; save buffer byte as search character + CMP #$22 ; is it quote character? + BEQ LAB_1410 ; branch if so (copy quoted string) + + CMP #'*' ; compare with "*" + BCC LAB_13EC ; if < go save byte then continue crunching + + ; else crunch now +LAB_13CC + BIT Oquote ; get open quote/DATA token flag + BVS LAB_13EC ; branch if b6 of Oquote set (was DATA) + ; go save byte then continue crunching + + STX TempB ; save buffer read index + STY csidx ; copy buffer save index + LDY #TAB_1STC ; get keyword first character table high address + STY ut2_ph ; save pointer high byte + LDY #$00 ; clear table pointer + +LAB_13D0 + CMP (ut2_pl),Y ; compare with keyword first character table byte + BEQ LAB_13D1 ; go do word_table_chr if match + +; *** replace +; BCC LAB_13EA ; if < keyword first character table byte go restore +; *** with + BCC PATCH_LC2 ; if < keyword first character table byte go restore +; *** end + ; Y and save to crunched + + INY ; else increment pointer + BNE LAB_13D0 ; and loop (branch always) + +; have matched first character of some keyword + +LAB_13D1 + TYA ; copy matching index + ASL ; *2 (bytes per pointer) + TAX ; copy to new index + LDA TAB_CHRT,X ; get keyword table pointer low byte + STA ut2_pl ; save pointer low byte + LDA TAB_CHRT+1,X ; get keyword table pointer high byte + STA ut2_ph ; save pointer high byte + + LDY #$FF ; clear table pointer (make -1 for start) + + LDX TempB ; restore buffer read index + +LAB_13D6 + INY ; next table byte + LDA (ut2_pl),Y ; get byte from table +LAB_13D8 + BMI LAB_13EA ; all bytes matched so go save token + + INX ; next buffer byte + CMP Ibuffs,X ; compare with byte from input buffer + BEQ LAB_13D6 ; go compare next if match + +;*** add + ORA #$20 ; repeat with lower case + CMP Ibuffs,X ; compare with byte from input buffer + BEQ LAB_13D6 ; go compare next if match +; *** end + + BNE LAB_1417 ; branch if >< (not found keyword) + +LAB_13EA + LDY csidx ; restore save index + + ; save crunched to output +LAB_13EC + INX ; increment buffer index (to next input byte) + INY ; increment save index (to next output byte) + STA Ibuffs,Y ; save byte to output + CMP #$00 ; set the flags, set carry + BEQ LAB_142A ; do exit if was null [EOL] + + ; A holds token or byte here + SBC #':' ; subtract ":" (carry set by CMP #00) + BEQ LAB_13FF ; branch if it was ":" (is now $00) + + ; A now holds token-$3A + CMP #TK_DATA-$3A ; compare with DATA token - $3A + BNE LAB_1401 ; branch if not DATA + + ; token was : or DATA +LAB_13FF + STA Oquote ; save token-$3A (clear for ":", TK_DATA-$3A for DATA) +LAB_1401 + EOR #TK_REM-$3A ; effectively subtract REM token offset + BNE LAB_13AC ; If wasn't REM then go crunch rest of line + + STA Asrch ; else was REM so set search for [EOL] + + ; loop for REM, "..." etc. + +LAB_1408 + LDA Ibuffs,X ; get byte from input buffer + BEQ LAB_13EC ; branch if null [EOL] + + CMP Asrch ; compare with stored character + BEQ LAB_13EC ; branch if match (end quote) + + ; entry for copy string in quotes, don't crunch +LAB_1410 + INY ; increment buffer save index + STA Ibuffs,Y ; save byte to output + INX ; increment buffer read index + BNE LAB_1408 ; loop while <> 0 (should never be 0!) + + ; not found keyword this go +LAB_1417 + LDX TempB ; compare has failed, restore buffer index (start byte!) + + ; now find the end of this word in the table +LAB_141B + LDA (ut2_pl),Y ; get table byte + PHP ; save status + INY ; increment table index + PLP ; restore byte status + BPL LAB_141B ; if not end of keyword go do next + + LDA (ut2_pl),Y ; get byte from keyword table + BNE LAB_13D8 ; go test next word if not zero byte (end of table) + + ; reached end of table with no match +; *** add label +PATCH_LC2 +; *** end +; *** end patch: lower case token recognition *** + + LDA Ibuffs,X ; restore byte from input buffer + BPL LAB_13EA ; branch always (all bytes in buffer are $00-$7F) + ; go save byte in output and continue crunching + + ; reached [EOL] +LAB_142A + INY ; increment pointer + INY ; increment pointer (makes it next line pointer high byte) + STA Ibuffs,Y ; save [EOL] (marks [EOT] in immediate mode) + INY ; adjust for line copy + INY ; adjust for line copy + INY ; adjust for line copy + DEC Bpntrl ; allow for increment (change if buffer starts at $xxFF) + RTS