hornc / fountain-expts Goto Github PK

I managed to start looking at this just (hours?) before a version update, and now my examples don't work :)

Updating 389450e..29fb426

is the 'it worked' -> 'doesn't work now' transition.

I'll figure out what needs to change.

Looks like I am relying on catch-all pre-conditions, which used to work, now doesn't in 0.4.

Round<a, rounds, drop> ::=
    (
         <. drop = 3 .> Drop<a>
       | <. drop = 7 .>  Catch<a> <. drop -= 7 .>
       | Catch<a>                  
    ) #10
;

Error msg: fountain.exe: No pre-condition present on these Alt choices: (Catch<a>)

Now that I check official examples, I'm not seeing a catch all pattern. I may have just made that up as a technique because it seemed to work.

In my current experiments, I'm using a lot of rules to change values with "" (empty string / ε) as the output...

This is not reversible, and probably breaks Fountain's ability to make sense parsing the generated output...

I haven't tried running these examples' outputs through the parsing direction, but it's just occurred to me that I might be relying heavily on a "feature" that's likely to disappear

Terminals probably shouldn't be blank... looking at the EBNF at https://github.com/catseye/Fountain/blob/29fb426732c4f83abb54f39f1a247d9f9e348ce5/doc/Definition-of-Fountain.md

It looks like that's what is specified : <<">> <<any except ">>+ <<">> (one or more character) but 0.4 is letting me get away with <<">> <<any except ">>* <<">> i.e. zero or more.

Probably can get around this but outputting something, but it'll be very noisy with the current constructs I have.