Named arguments

Named arguments (they are also called as flags or options) have one or more name that can be separated into two categories:

Short names are those that start with single dash - (see Config.namedArgPrefix for customization).
Long names start with double dash -- (see Config.namedArgPrefix for customization).

Both cases are fully supported with one caveat: if a single-character argument is used with a double dash (e.g., --n) in command line, then it behaves the same as a multi-character argument.

The following usages of the argument in the command line are equivalent:

--name John
--name=John
--n John
--n=John
-n John
-n=John
-nJohn - this works for single-character names only

Named arguments can be declared using NamedArgument UDA which has the following parameters:

#	Name	Type	Optional/ Required	Description
1	`name`	`string` or `string[]`	optional	Name(s) of this argument that can show up in command line.

Name

Type

Optional/

Required

Description

name

string or string[]

optional

Name(s) of this argument that can show up in command line.

Example:

import argparse;

struct Params
{
    // If name is not provided then member name is used: "--greeting"
    @NamedArgument
    string greeting;

    // If member name is single character then it becomes a short name: "-a"
    @NamedArgument
    string a;

    // Argument with multiple names: "--name", "--first-name", "-n"
    // Note that single character becomes a short name
    @NamedArgument(["name", "first-name", "n"])
    string name;

    // Another way to specify multiple names: "--family", "--last-name"
    @NamedArgument("family", "last-name")
    string family;
}

Last modified: 09 November 2024