Mercurial > hg > index.cgi
changeset 43:b27b34d0afff
Fix line number parsing to actually handle first character
It turns out that if you clobber the first character of your input line
number, you don't end up with a correct result when parsing.
| author | William Astle <lost@l-w.ca> |
|---|---|
| date | Fri, 09 Dec 2022 22:00:17 -0700 |
| parents | 1f74c2df443f |
| children | c04068c37316 |
| files | src/lwbasic.s |
| diffstat | 1 files changed, 2 insertions(+), 1 deletions(-) [+] |
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--- a/src/lwbasic.s Fri Dec 09 21:34:31 2022 -0700 +++ b/src/lwbasic.s Fri Dec 09 22:00:17 2022 -0700 @@ -1137,9 +1137,10 @@ ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Parse a line number and return it in binval; raise syntax error if the line number overflows 16 bits unsigned. ; Preserves; registers except D. This will accept the entire 16 bit unsigned number range which is why there is -; a BCS after every shift or add. Enter with the first character in A with C set for digits and clear otherwise. +; a BCS after every shift or add. Enter with the input pointer pointing to the number to parse. parse_lineno ldd zero ; clear out accumlator but preserve carry flag std binval + jsr curchar ; set flags on current character; skip spaces bcc parse_lineno1 ; brif first character wasn't a digit - default to zero parse_lineno0 suba #0x30 ; adjust to binary digit pshs a ; save digit so we can add it later