Return to the
comp.compilers page.
Search the
comp.compilers archives again.
| Related articles |
|---|
| How to improve the error handling of my scanner? johnwilliams40@live.com (John Williams) (2009-01-10) |
| Re: How to improve the error handling of my scanner? DrDiettrich1@aol.com (Hans-Peter Diettrich) (2009-01-13) |
| From: | Hans-Peter Diettrich <DrDiettrich1@aol.com> |
| Newsgroups: | comp.compilers |
| Date: | Tue, 13 Jan 2009 03:58:25 +0100 |
| Organization: | Compilers Central |
| References: | 09-01-019 |
| Keywords: | parse, errors |
| Posted-Date: | 13 Jan 2009 07:32:05 EST |
John Williams schrieb:
> I finally built my scanner and parser using Coco/R, but I need some help to
> improve error handling.
>
> For example, I tried to parse the following program:
>
> MODULE Program;
> VAR 4fgnn : INTEGER;
> END Program.
>
> There's obviously an error with "4fgnn", it is a bad identifier because it
> starts by a number. This is the compiler output:
>
> line 2 col 12: "END" expected
>
> Of course it detects the error, but it is kind of vague.
It's a matter of your grammar, what errors can be caught in which places.
When "4fgnn" is scanned as a number and an identifier token, no rule
should exist that accepts a sequence of "VAR" <number>.
DoDi
Return to the
comp.compilers page.
Search the
comp.compilers archives again.