outil

Types

Argument

A positional command line argument.

pub type Argument {
  BoolArgument(name: String)
  FloatArgument(name: String)
  IntArgument(name: String)
  StringArgument(name: String)
}

Constructors

```
BoolArgument(name: String)
```
```
FloatArgument(name: String)
```
```
IntArgument(name: String)
```
```
StringArgument(name: String)
```

Command

</>

A command line interface to a run function.

pub type Command {
  Command(
    name: String,
    description: String,
    arguments: List(Argument),
    options: List(Opt),
    argv: List(String),
  )
}

Constructors

Command(
  name: String,
  description: String,
  arguments: List(Argument),
  options: List(Opt),
  argv: List(String),
)

CommandResult

</>

The result of executing a command.

pub type CommandResult(a, b) =
  Result(a, CommandReturn(b))

CommandReturn

</>

Non-normal return values from executing a command.

pub type CommandReturn(a) {
  CommandLineError(reason: Reason, usage: String)
  CommandError(a)
  Help(usage: String)
}

Constructors

CommandLineError(reason: Reason, usage: String)

An error in parsing the command line.

```
CommandError(a)
```
An error in executing the command, a is your error value.
```
Help(usage: String)
```
The user asked for help.

Opt

</>

A command line option/flag.

pub type Opt {
  Opt(
    long: String,
    short: Option(String),
    description: String,
    value: OptValue,
  )
}

Constructors

Opt(
  long: String,
  short: Option(String),
  description: String,
  value: OptValue,
)

OptValue

</>

The type and default value of an option.

pub type OptValue {
  BoolOpt
  FloatOpt(default: Float)
  IntOpt(default: Int)
  StringOpt(default: String)
}

Constructors

```
BoolOpt
```
```
FloatOpt(default: Float)
```
```
IntOpt(default: Int)
```
```
StringOpt(default: String)
```

Functions

command

</>

pub fn command(
  name: String,
  description: String,
  argv: List(String),
  continue: fn(Command) -> a,
) -> a

Create a command with the given name and description, and pass it to the given continuation function for further configuration.

The command gets a default implementation that returns an error.

parse_bool

</>

pub fn parse_bool(arg: String) -> Result(Bool, Nil)

Parse a Bool from a string.

print_usage

</>

pub fn print_usage(return: CommandReturn(a)) -> Nil

Convenience function for handling the result of executing a command.

Print usage if there was a command line error or if the user asked for it.

Does nothing if the command returned an application error, assuming that the application will handle it.

print_usage_and_exit

</>

pub fn print_usage_and_exit(return: CommandReturn(a)) -> Nil

Convenience function for handling the result of executing a command.

Print usage if there was a command line error or if the user asked for it.

Exit with 2 if there was a command line error, 1 if there was a command error, or 0 if the command was successful.