Item10386: OP_where parses successfully even when the closing bracket is missing

OP_where parses successfully even when the closing ] is missing

Which may lead to ambiguity if there is anything following it?

-- SvenDowideit - 21 Feb 2011

There is no risk of ambiguity. The parser is a simple-stack-based parser, where brackets are parsed bvy a stack push and recursive call of the parser until either (1) the matching bracket or (2) the end of the string is hit. If the EOS is hit earlier, it forces a stack flush of however levels remain open.So it will parse "A[B" and "A[B[C" successfully (and correctly).

It would be easy to modify this behaviour to report an error, but the error handling through the SEARCH macro is so crap that I chose to be lenient. The language definition requires the closing braces, even if the implementation does not.

-- CrawfordCurrie - 22 Feb 2011

I think you have just confirmed that. yes, there is ambiguity for the user. i realise there is only one way the parser will deal with it - the point is that like all code, if what the parser does due to missing syntax is not what the user intended, then we've created an ambiguous situation.

-- SvenDowideit - 22 Feb 2011

In the grand scheme of things, I think we can live with this.

-- CrawfordCurrie - 15 Mar 2011

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