Re: [SPAM] strict productions

I'm not at all sure we really want a trilingual compiler, but the parser is complete or nearly so, it's probably worth a look.

--------------------------| John L. Ries | Salford Systems | Phone: (619)543-8880 x107 | or (435)867-8885 | --------------------------|

On Wed, 15 Feb 2017, Bastiaan Veelo wrote:

  On 15 Feb 2017, at 18:10, Paul Isaacs
  <paul@redpineinstruments.org> 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.