Erroneous ~ not highlighted

[ojwb]

Following on from #20...

The current state is better than before the fix for #20, but ~ now seems to be treated as an operator like +, etc but really it's more like ' as it can't be used in most expressions. I think it only works in PRINT and as the next token after STR$ (so A$=STR$~(12) and B$=STR$~12 work, but C$=STR$(~12) doesn't.)

Admittedly a minor issue, but ideally A=~B should show ~ in red.

[ojwb]

Similarly these are also currently treated as operators or symbols but aren't valid in general and it would be nicer to show them in red when misused:

• ' is only valid in INPUT and PRINT.
• # is only valid right after certain tokens - BGET#, BPUT#, CLOSE#, EOF#, EXT#, INPUT#, PRINT#, PTR#,
• ; is only valid in INPUT, PRINT and VDU

[ojwb]

• # is only valid right after certain tokens - BGET#, BPUT#, CLOSE#, EOF#, EXT#, INPUT#, PRINT#, PTR#,

I've pushed a fix for # handling so it's now coloured as a syntax error in places where it isn't valid.

We don't currently take account of the more restricted syntax of INPUT# and PRINT# but we don't try to handle the exact syntax of most BASIC commands either. Also INPUT# and PRINT# are relatively obscure and aren't likely to be useful with the bot because there's no disk or tape to read from/write to.