Anura is a free open-source cross-platform 2D game engine written in C++. It has a built-in interpreter for FFL (Frogatto Formula Language), a pure functional language used to code its games or other modules. Its module code and configuration data are stored in FSON, a custom version of JSON. Use this tag for all issues related to building, installing, or developing content with the Anura game engine.
Questions tagged [anura]
9 questions
2
votes
2 answers
advanced ffl: conditional expression then-expressions activation
Here is a snippet from https://github.com/anura-engine/anura/blob/55bc02244f0faba5e0831578a3c1c9a82e7bf569/src/formula_function.cpp#L923-L931:
FUNCTION_DEF(if, 2, -1, "if(a,b,c)")
const int nargs = static_cast(NUM_ARGS);
…
1737973
- 159
- 18
- 42
2
votes
2 answers
keyword - FFL: Where vs. Let
I was trying to understand the following code:
def() ->commands
if(deferred_passive_abilities != [],
let [{ability: class passive_ability, creature: class creature}] items = [];
let found = false;
…
Patrick Parker
- 4,863
- 4
- 19
- 51
0
votes
1 answer
`ld` complains of no such file or directory, when it exists by exact name
I have a rather old-school Makefile which calls g++ to compile my program on Ubuntu¹. When I run make, it prints out the following error after some compilation happens.
/usr/bin/ld: cannot find -l/usr/lib/x86_64-linux-gnu/libX11.so: No such file or…
DDR
- 392
- 1
- 4
- 14
0
votes
1 answer
FFL: second identifier from where clause not recognized
I believe my syntax is correct on this one, but for some reason the Anura FFL parser is not recognizing the second identifier choice defined in my where clause. What am I missing?
def(class creature creature, class game_state game) ->commands [
…
Patrick Parker
- 4,863
- 4
- 19
- 51
0
votes
1 answer
Combine asserting clauses with where clauses
I have noticed that when I have multiple where clauses and multiple asserting clauses, that I get often get syntax errors when I combine them together. The error will say "unexpected token after where". How should I write it to avoid this error?…
Patrick Parker
- 4,863
- 4
- 19
- 51
0
votes
2 answers
filter max of N
Could it be possible to write in FFL a version of filter that stops filtering after the first negative match, i.e. the remaining items are assumed to be positive matches? more generally, a filter.
Example:
removeMaxOf1([1,2,3,4], value>=2)
Expected…
Patrick Parker
- 4,863
- 4
- 19
- 51
0
votes
1 answer
Understanding the evaluation and execution order with semicolon syntax
I already learned a little bit about FFL semicolons from my previous question. However, it is still not clear what order of evaluation or execution they enforce. So here is a more concrete example:
[ expr_a, expr_b ; expr_c, expr_d ; expr_e, expr_f…
Patrick Parker
- 4,863
- 4
- 19
- 51
0
votes
1 answer
Understanding the lib keyword
Is lib a special keyword for Frogatto Formula Language (FFL)? That seems to be the way of invoking class methods. For example:
where frog = lib.citadel.create_creature('Giant Frog')
Also, I am interested to know where can I find a list of all the…
Patrick Parker
- 4,863
- 4
- 19
- 51
0
votes
1 answer
should FFL where clause allow referring to previous variable?
So, in Frogatto Formula Language we can have a where clause with multiple assignments, like where a = yadda, b = foo
However I can't refer to a in the assignment of b ?
I was hoping to simplify by breaking it into steps, where a = ..., b =…
Patrick Parker
- 4,863
- 4
- 19
- 51