Skip to main content

Positional Arguments

All non-flag arguments passed to the CLI are considered in order, parsed, and then passed to the rest arguments of the command. While flags can be parsed or additionally support a variety of built-in types, all positional arguments must be parsed from strings with a provided parser. These support any strings, but by default any inputs starting with - or -- will be interpreted as flags instead. To escape this behavior, consider using the argument escape sequence.

Variadic Limits​

Stricli reserves the first argument in the implementation function for Flags and considers the rest as positional arguments. While it is possible to have overloads or other complex function signatures, Stricli only supports cases where the arguments are either all explicitly specified (flags, a, b, c) => {} or a single rest array where all of the elements are the same type (flags, ...args: T[]) = {}.

Tuples​

When the function arguments are individually specified, Stricli will infer the types of the parameter definitions.

Homogenous Arrays​

The only other supported pattern for command functions matches the flags as the first argument and then the rest of the arguments as a single array with a single type. This element type of the array could be a more complex type depending on the parse function provided.

Bounds​

In general TypeScript, it is possible to use a tuple type as the type of a rest parameter. This allows for more complex function signatures to be represented. These are not supported, but Stricli does provide some additional features for homogenous arrays.

The minimum and maximum bounds can be provided to a parameter, and then Stricli will ensure that any encountered arguments fall within those bounds.

Variants​

Most positional arguments support variants, some of which are enforced through type checking.

Optional​

If an argument is optional, or is otherwise possibly undefined then it must have optional: true in its configuration. This is enforced by TypeScript based on the type of the corresponding property.

Default​

Any argument can specify a default value as a string. This string will be parsed before being passed to the implementation.

Placeholder​

Positional arguments don't truly have names as a name cannot be included in the input (for named arguments, use flags instead). However, they still have a semantic meaning and it can be useful to refer to it with a name for simplicity. To avoid confusion with named flags, you can specify a "placeholder" for positional arguments. These placeholders are used in the auto-generated usage lines and in the help text.