SBL - Stack Based Language

Original name, right?

If you're just getting started, check the wiki! (Wiki is out of date and contains some really old, phased-out syntax - peruse at your own risk)

Please don't use this for anything real, it's just a toy language.

This is what it looks like:

; Calculates n factorial (n!).
fact {
    ; duplicate and compare to zero
    ^ 0 ==
    br {
        .@
        ; pop off to nothing, and push a 1
        .@ 1
    }
    el {
        .@
        .x       ; pop into x
        x 1 -    ; push a copy and subtract 1 from it
        fact     ; call factorial
        x *      ; multiply whatever our factorial is by x
    }
}

main {
    @ 5 4 3 2 1
    loop { fact println }
}

Installing

This project requires Rust 1.19 stable (nightly and beta should also work).

git clone https://github.com/alekratz/sbl-rs
cd sbl
cargo build

If you want to build a release version, tack --release to the end of the cargo invocation.

Optionally if you want to run sbl from the command line, run cargo install. Otherwise, you can run the program from target/{debug,release}/sbl file.sbl or cargo run -- file.sbl.

Basic usage

All SBL supports right now is running directly from a file. If you wish to import code from multiple files, multiple files may be supplied from the command line.

Examples

• sbl test.sbl

Note that SBL files must not contain duplicate functions; this is a compile-time error if they do.

Grammar

You can check out the grammar in GRAMMAR.md.

Features

• Terse syntax
• Tacit-style programming
• Recursive functions
• Order-agnostic function definition
• Simple, LL(0) grammar
• Built-in function support
• A handful of primitive types
• File path imports
  • Include paths, too!
• Ability to call (some) foreign functions
• More to come...

Non-features

Or, "room for improvement"

• No savable bytecode (see #10)
• No base or standard library (see #11)

Planned features

Check out the planned feature tag on the issues page.

This is the list of features that are officially planned and ready to be implemented that have not yet been added. All features are open for discussion.

Releases

None yet!

Contributing

Contributions are welcome and happily accepted. Check out CONTRIBUTING.md for more details.

License

Apache2. See LICENSE file for details.