Tomo - Tomorrow's Language

Tomo is a statically typed, safe, simple, lightweight, efficient programming language that cross-compiles to C. Tomo is designed to anticipate and influence the language design decisions of the future.

func greeting(name:Text, add_exclamation:Bool -> Text):
    message := "hello $name"
    message = " ":join([w:title() for w in message:split_any(" ")])
    if add_exclamation:
        message ++= "!!!"
    return message

func main(name:Text, shout=no):
    to_say := greeting(name, add_exclamation=shout)
    say(to_say)

$ tomo hello.tm -- world
Hello World
$ tomo hello.tm -- --name=åke
Hello Åke
$ tomo -e hello.tm
$ ./hello "john doe" --shout
Hello John Doe!!!

For more examples, see learnXinY which as an overview of many language features or the other example programs/modules in examples/.

Features

Performance

• Generates performant C code with minimal overhead that runs as fast as C code, because it is C code.
• Extremely fast incremental and parallel compilation
• Language-level support for correct function caching
• Structs with known-at-compile-time methods, not OOP objects with vtable lookups

Safety

• Memory safety (garbage collection, compiler-enforced null safety, automatic array bounds checking, and no uninitialized variables)
• High-performance arbitrary-precision integers by default with opt-in fixed-size integers with arithmetic overflow checking
• Type-safe strings representing different languages with automatic prevention of code injection
• Pattern matching with exhaustiveness checking for enumerated types (tagged unions/enums)
• Type-safe optional values with low syntax overhead
• Efficient datastructures with immutable value semantics: arrays, tables, sets, text.
• Privacy-protecting types that help prevent accidentally logging sensitive information

Simplicity

• Simple, low-boilerplate type system with type inference
• Well-defined reference and value semantics and mutability rules
• No polymorphism, generics, or inheritance

User-friendliness

• String interpolation and debug printing builtins
• Built-in datastructures with a rich library of commonly used methods: arrays, tables, sets, text.
• Full-featured libraries/modules
• Full UTF8 support for all text operations
• Built-in doctests with syntax highlighting
• Automatic command line argument parsing with type safety
• Easy interoperability with C
• Built-in data serialization and deserialization.

Dependencies

Tomo has a very small set of dependencies:

• GCC version 12 or higher (might work on lower versions, but has not been tested)
• The Boehm garbage collector for runtime garbage collection.
• libunistring for unicode string support (version 1.0 or higher)
• GNU multiple precision arithmetic library for arbitrary precision integer math (version 6.2.1 or higher)
• Patchelf for building tomo libraries
• Binutils for stack traces.
• and libc/libm, which should definitely already be installed.

If you're feeling incautious, you can run make deps or ./install_dependencies.sh to install all the necessary dependencies. I can't guarantee this works on all platforms, but has a reasonably high chance of success.

Building

The Tomo compiler can be compiled with either GCC or Clang by running make. The resulting compiler and shared library will be put into ./build/.

Usage

Run Tomo interactively as a REPL (limited functionality):

tomo
# Starts a REPL session

Run a Tomo file directly:

tomo foo.tm
# Runs the program

Compile a Tomo file into an object file:

tomo -c foo.tm
# Output: .build/foo.tm.o

Transpile a Tomo file into a C header and source file:

tomo -t foo.tm
# Outputs: .build/foo.tm.h .build/foo.tm.c

Installing

make && sudo make install

License

Tomo is provided under the Sustainable Use License (see LICENSE.md for full details). This is a source-available fair-code license that does not grant unlimited rights for commercial use, but otherwise has permissive rights for noncommercial use and allows distributing and modifying the source code. It does not comply with the Open Source Initiative's definition of "Open Source", which does not allow any restrictions on commercial use. If you would like to use this project commercially, please contact me to work out a licensing agreement.