[whatwg] Conformance requirements on conformance checkers

[Henri Sivonen]

Quoting from http://whatwg.org/specs/web-apps/current-work/#parsing :
> Conformance checkers must report all parse error conditions (both hard 
> and easy errors) to the user, but may apply error correction 
> algorithms (those described in the spec for easy errors, and those 
> reverse-engineered from other UAs for hard errors) in an attempt to 
> continue past the location of the error and find the remaining errors.

The latter part of the sentence somewhat implies that the parser might 
not be required (in the MUST sense) continue to find all errors. 
However, the start of the requirement could be clearer.

I'd prefer something like this:
Conformance checkers must report at least one parse error condition to 
the user if one or more parse error conditions exist in the document 
and must not report parse error conditions if none exist in the 
document. Conformance checkers may report more than one parse error 
condition if more than one parse error conditions exist in the 
document. Conformance checkers are not required to recover from parse 
errors (not even easy parse errors).

Rationale:
Considering the purpose of a conformance checker, it should be 
sufficient for the conformance checker to find out whether the document 
is conforming. Additional reporting should be a feature bargain between 
the conformance checker developer and users--not a hard spec 
requirement. Besides, XHTML flavor conformance checking is likely to 
stop on the first well-formedness error anyway.

-- 
Henri Sivonen
hsivonen at iki.fi
http://hsivonen.iki.fi/