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Via command line

Installation

Prerequisites:

  • Rust toolchain

To install the CLI, run:

cargo install --index 'https://codeberg.org/lutra/_cargo-index.git' lutra-cli

Note

While Lutra (the project) is in a pre-release state, none of the packages are yet published to crates.io. Instead, we use a custom registry at codeberg.org to host the packages. This is why we need to use the --index flag to tell cargo to use this registry.

Command run

The most basic command is run, which executes a Lutra program.

Options:

  • choice of a runner, which can be set to either:

    • --interpreter, or
    • --postgres <connection-string>

  • --program <Lutra expression> which is the program to execute. Default to main (a reference to the main function).

  • --project <file.lt> path to a project file.
  • --input <file.lb> path to the input file in Lutra binary format.
  • --output <file.lb>path to the output file in Lutra binary format.

Examples

Execute a program on a local interpreter:

$ lutra run \
    --interpreter \
    --program 'std::fold([1, 2, 3], 0: int32, func (s, v) -> s + v)'
6

Execute a program on PostgreSQL:

$ lutra run \
    --postgres 'postgresql://postgres:password@localhost:5432/postgres' \
    --program 'std::fold([1, 2, 3], 0: int32, func (s, v) -> s + v)'
6

Use a project file:

# project.lt

func hello(name: text): text -> (
    f"Hello, {name}!"
)

$ lutra run \
    --interpreter \
    --project ./project.lt \
    --program 'hello("world")'
"Hello, world!"

Write and read Lutra binary files:

$ lutra run \
    --interpreter \
    --program '{a = false, name = "world"}' \
    --output ./data.lb
Output written to ./data.lb (14 bytes)

$ lutra run \
    --interpreter \
    --input ./data.lb \
    --program 'func(x: {a: bool, name: text}) -> f"Hello, {x.name}!"'
"Hello, world!"

Command check

Validates a Lutra project. Parses all files and resolves all names and types.

Options:

  • --program <Lutra expression> the program to check.
  • --project <file.lt> path to a project file.

Examples

Validate a project file:

$ lutra check --project ./project.lt

Command codegen

Generates bindings of a Lutra project for a target language (Rust or Python).

Arguments:

  • <project> path to a project file.
  • <output file> path to the output file.

The output file path must end with .rs or .py depending on the target language.

Examples

Generate Rust bindings:

$ lutra codegen --project ./project.lt ./lutra.rs
Used files:
- project.lt
Output written to lutra.rs
Done.

Other commands

There other, less stable commands.

$ lutra --help
Usage: lutra [OPTIONS] <COMMAND>

Commands:
  discover         Read the project
  check            Validate the project
  compile          Compile a program
  run              Compile a program and run it
  pull             Pull interface from the runner
  codegen          Compile the project and generate bindings code
  format           Format source files
  language-server  Start language server (LSP)
  help             Print this message or the help of the given subcommand(s)

Options:
  -v, --verbose
  -h, --help     Print help