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 $name"
    message = " ":join([w:title() for w in message:split($/{space}/)])
    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)
• Arbitrary-precision integers by default with opt-in fixed-with 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
• Integers with the default type do not overflow, they seamlessly transition from fixed-width integers to bigints as needed.

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
• Support for POSIX threads and thread-safe message passing queues over channels.

Dependencies

Tomo has a very small set of dependencies:

• The Boehm garbage collector for runtime garbage collection.
• libunistring for unicode string support.
• GNU multiple precision arithmetic library for arbitrary precision integer math.
• Binutils for stack traces.
• a C compiler
• and libc/libm, which should definitely already be installed.

The Boehm GC, libunistring, and binutils should be available on your package manager of choice (for example, pacman -S gc libunistring binutils).

Building

The Tomo compiler can be compiled with either GCC or Clang by running make.

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: foo.tm.o

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

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

Tomo uses the environment variables ($CC, $VERBOSE, and $AUTOFMT), which control the compilation/running behavior of Tomo. The default behavior is to use tcc (Tiny C Compiler) for fast compilation, VERBOSE=0, and AUTOFMT='indent -kr -l100 -nbbo -nut -sob' for autoformatting generated code. Any of these variables may be overridden, e.g. CC=gcc VERBOSE=1 AUTOFMT= tomo foo.tm (compile with GCC and verbose compiler output without autoformatting the code).

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.