jespercockx/agda2scheme

Compiler backend for generating Scheme code

agda2scheme's Issues

Add support for imports

In order to make the backend practically useable, it needs to have support for imports from other files.

One choice that needs to be made is whether we compile each Agda file to a separate Scheme file, or if we join all files together into a single master file. Since Chez Scheme does not do cross-module optimizations, the latter would have better performance, but it would mean we give up on separate compilation.

Support more built-in types

The following built-in types of Agda are not yet supported:

• Integers
• Floats
• Chars
• Strings
• Word64

Note that by default, Scheme uses complex numbers, so we need to use the flo-prefixed versions of operations on floats.

Add support for main function

Currently Agda2Scheme compiles Agda definitions to Scheme definitions, but there is no way yet to indicate a main function.

One question here is whether we want something like the IO monad in Haskell to mediate basic input/output effects, or if we just use a more direct style of doing IO.

Don't store constructor tag for records and single-constructor datatypes

Currently constructors always store a tag, even when there is only a single option.

As a stretch goal, we could even skip the constructor tag if there are several constructors, as long as there is only a single constructor of each given arity. We can then just determine which constructor we have by looking at the length of the argument list.

Use projections instead of match for single-case matches

Instead of matching, we could instead just project out the fields of the record directly.

Add a Makefile

Add a benchmarking suite

Here is how I am running my benchmarks so far:

cd test
agda2scheme --lazy Triples.agda
echo '(display (test1)) (display "\n")' >> Triples.ss
echo '(compile-file "Triples.ss")' | chezscheme -q
time chezscheme --script Triples.so

It would definitely be good to automate this.

Adding CI using Github Actions?

Hello,
Thank you for creating this repository. I am studying this to learn how to write backend in Agda!

I play around with adding CI support to this on my fork here lemastero#1, would it make sense to open such PR towards this repository?

Compile nat-like and int-like types to integers

It would be cool if we could detect automatically types that are sufficiently like natural numbers or integers, and represent them using actual integers in the compiled code. As a stretch goal, we could even try to detect that certain functions are just addition/subtraction/... and compile them to more efficient versions as well.

Don't use lazy thunks for arguments that are always used

Currently compiling code with the --lazy flag incurs a quite heavy performance overhead (e.g. the slowdown is over 10x on Triples.agda). If we could analyze which arguments are always used by a given function, then we could avoid creating delay thunks for those arguments and instead evaluate them strictly. I started implementing this analysis in 2834874, but it is not yet clear to me how to do this analysis properly for mutually recursive functions.

Add a test runner

Use arrays instead of lists to represent constructors

Arrays give constant-time access to their elements so they might be more efficient, especially for record types with many fields.

We could also consider using arrays to represent argument lists for functions with a high arity.

Automate unit tests

Hello,
In test directory there are golden tests, but there is no code that actually illustrate how to run them.
Since this repo works as example how to build backend, it would be nice to have unit tests encoded in Haskell.

Add support for foreign functions

In order to support custom primitives for doing IO and such, it would be good to support FOREIGN pragmas to include snippets of Scheme code into the Agda source.