Interface OptionSpec

Aliases for the option or command. Can be a single string or an array of strings.

Default argument values for the option or command.

After parsing, the parser applies this accordingly:

• For options: if the user didn't specify the option, the parser will automatically add the option with the default value.
• For commands: if the user specifies the command without any arguments.

The source will be "default".

Specifies arguments for the command or option.

• Format: "<name type>" or "[name type]". Types: number, string, boolean, and float.
  • <> denotes a required argument, while [] denotes an optional argument.
    • All required arguments must precede optional arguments.
  • The default type is string and can be omitted, e.g., "<name>". A blank space omits name, e.g., "< string>". Both can be omitted, e.g., <>.
  • Examples: "<arg string>", "[arg number]", or "<arg1 boolean> <arg2 string>".
• Array arguments: specify with ..N or ..
  • Fixed size array: "<arg string..3>" or "<..3>" means 3 arguments are required.
  • Variadic size array: "<..>" for 0 to many; "<..1,>" or "<..1,Inf>" for 1 to many, indicating at least 1 is required.
    • Only the last argument can be variadic.

Specifies handlers for custom types.

The handler can be one of:

• A function: the return value will be taken as the argument value.
• A RegExp: if matched, the first entry from the matched result will be used as the argument value.
• A string: the string will be used as the argument value.

Example:

{
  myCustomType: (value) => value.toLowerCase()
}
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Description of the option or command. Can be a string or a function that returns a string.

name of the option or command

Indicates whether the command/option is required. If true, the command/option must be specified.