Builtin definition by YAML/JSON/NEON

[Mte90]

Taking as example #311

An idea is to write builtin in this way:

builtin:

  name: ChangeDirectory
  keyword: cd
  failable: true
  output: cd {} || exit
  description: Some text lorem ipsum
  parameters:
    1: 
        - label: destination
        - type: string

So to compile will read the definitions files and will add in the engine.
It will be less code to maintain and it is more easy to generate documentation and implement them.

[Ph0enixKM]

It's a good idea untill we need to change some builtin a little bit in a way that can't be expressed in YAML

[Mte90]

I don't know if it is missing something in my proposal but evverything that can simplify the Amber code I think that is important for stability and keep up with internal changes like we are now with the doc generator PR.

[b1ek]

im not sure i feel comfortable with this sort of change. as of right now builtins are structs which are defined statically in their .rs file.

maintaining macros is a pain in the ass, especially big and complex ones like this

[Mte90]

Yeah I think that we can work on a better structure and what kind of builtins we want to define in this way.

Right now what we have as builtin are just command wrapper with anything else.

[mks-h]

The output of a builtin may need to be different depending on its context, and may need to programmatic.

[CymDeveloppement]

why not an alias (or other keyword) definition :
alias failable cd="cd {}" cd "/mydir"
alias unsafe print_int ="printf \"%d\" {}" print_int 14
this can be easy to integrate all compatible posix command in stdlib
User can extend with her own definition

[CymDeveloppement]

alias unsafe pwd="pwd": Text let cwd = pwd

[Mte90]

So we can add the description of the command as a comment before the alias definition but for the builtin name?
Maybe like:

/*
 * Name: ChangeDirectory
 * Description: Change the current folder
 */
alias failable cd="cd {} || exit"
/*
 * Name: Printf
 * Description: Just printf!
 */
alias print_int ="printf \"%d\" {}"

We can create a folder organization like for stdlib for this content, as it is seems like Amber code.

What do you think @Ph0enixKM?

[Mte90]

The problem of a code like this, if you want to have a multiline alias?
Because for rm we should check also if the file exists as example and import the stdlib automatically

[mks-h]

It will be less code to maintain

It may be less lines of code to maintain, which is also unlikely, but the complexity increases by one more indirection. Writing and maintaining abstract layers is more complex than simple trait implementations.

[Mte90]

I suggested to implement a way for simpler builtin in this way and for complex one in pure Rust.

Also for the documentation we can add a parameters that will help for that.
Right now builtins are just wrappers for commands like cd or others and I think that we can do a lot of these.

[mks-h]

Looking at Associated Constants Examples, it seems like we may be able to make a trait for builtins that will only require specifying some constants, and the rest of the implementation will be provided automatically. Plus, things that need something extra may override the default implementation.

This won't generate docs, though