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.

It is just a grammar production, which I chose to interpret recursively. Whether it's productive when interpreted corecursively depends on the particular interpretation, I guess, and may not actually depend on factors like left recursion. I haven't thought about it much. Roman