On Sun, Feb 24, 2013 at 10:04 PM, Tillmann Rendel < [email protected]> wrote:
> The recursion is well-founded if (drop n1 text) is smaller then text. So > we have two cases, as Roman wrote: > > If the language defined by B contains the empty string, then n1 can be 0, > so the recursion is not well-founded and the parser might loop. > Ah! So "A ::= B A" is really /not/ the full grammar of the language but an abbreviated one, minus terminals. At the very least, partial parses make sense and the input stream is assumed finite. Because "A ::= B A" could be understood, not so much as a parsing rule, but as the full definition of a language which comprises only one word: BBBBB ... ad infinitum. So all that mention of well-foundedness was confusing. Thanks, Tillmann! -- Kim-Ee
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