Re: [SPAM] strict productions

> On 15 Feb 2017, at 18:10, Paul Isaacs <[email protected]> wrote:
> Interesting:
> 
> function-access1 = record-function1.field1  => using function-access|record-function
> record-function1 = function-access2         => using record-function production
> function-access2 = record-function2.field2  => using function-access|record-function
> record-function2 = x( a )                   => using function-access|entire-function
> 
> function-access2 = x( a ).field2            => reducing function-access2
> record-function1 = x( a ).field2            => reducing record-function1
> function-access1 = x( a ).field2.field1     => reducing function-access1
> 
> x( a ).field2 compiles and executes
> 
> x( a ).field2.field1 of course does not compile unless field1 is a field of field2. 

I can’t say I follow you exactly...

> But is it a syntacticly correct result of these productions?
> If so is it an ambiguity in the grammar? Do the productions have precedence rules?
> e.g. variable-access has higher precedence than function-access

I wrote a recursive descent parser for Extended Pascal in the D language using the Pegged library, which takes the rules of the standard almost literally. I remember changing the order of options in some rules, but I am unsure whether that was for efficiency or for giving precedence to common constructs. I do remember seeing ambiguities in variable access and function access, which I imagine can be resolved by keeping a symbol table of earlier definitions.

My parser is an interesting project but turned out to be rather inefficient at the moment. If there is an interest I will consider to put it online.

Bastiaan.

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