Re: [Haskell-cafe] Parser left recursion

* Kim-Ee Yeoh [2013-02-24 19:22:33+0700]

On Sun, Feb 24, 2013 at 7:09 PM, Roman Cheplyaka wrote:

...

Thus, your recursion is well-founded — you enter the recursion with the input strictly smaller than you had in the beginning.

Perhaps you meant /productive/ corecursion? Because the definition "A ::= B A" you gave is codata.

Or perhaps you meant that the production itself, when interpreted as a definition, is corecursive? Well, yes, and so is any CFG written in BNF. But that doesn't buy us much, and is irrelevant to the discussion of parsing left-recursive grammars. Roman