Arg::default_missing_value

default_missing_value

since 0.1.0

Value for the argument when the flag is present but no value is specified.

Examples

Example 1

Spec

TOML

name = "prog"
[args]
color = { long = "color", value-name = "COLOR", value-parser = ["always", "auto", "never"], default-value = "auto", num-args = "optional", require-equals = true, default-missing-value = "always", help = "Specify WHEN to colorize output." }

YAML

name: prog
args:
  color:
    long: color
    value-name: COLOR
    value-parser:
    - always
    - auto
    - never
    default-value: auto
    num-args: optional
    require-equals: true
    default-missing-value: always
    help: Specify WHEN to colorize output.

JSON

{
  "name": "prog",
  "args": {
    "color": {
      "long": "color",
      "value-name": "COLOR",
      "value-parser": [
        "always",
        "auto",
        "never"
      ],
      "default-value": "auto",
      "num-args": "optional",
      "require-equals": true,
      "default-missing-value": "always",
      "help": "Specify WHEN to colorize output."
    }
  }
}

Input

prog

Output

claptrap_color='auto'

Example 2

Spec

TOML

name = "prog"
[args]
color = { long = "color", value-name = "COLOR", value-parser = ["always", "auto", "never"], default-value = "auto", num-args = "optional", require-equals = true, default-missing-value = "always", help = "Specify WHEN to colorize output." }

YAML

name: prog
args:
  color:
    long: color
    value-name: COLOR
    value-parser:
    - always
    - auto
    - never
    default-value: auto
    num-args: optional
    require-equals: true
    default-missing-value: always
    help: Specify WHEN to colorize output.

JSON

{
  "name": "prog",
  "args": {
    "color": {
      "long": "color",
      "value-name": "COLOR",
      "value-parser": [
        "always",
        "auto",
        "never"
      ],
      "default-value": "auto",
      "num-args": "optional",
      "require-equals": true,
      "default-missing-value": "always",
      "help": "Specify WHEN to colorize output."
    }
  }
}

Input

prog --color=never

Output

claptrap_color='never'

Example 3

Spec

TOML

name = "prog"
[args]
color = { long = "color", value-name = "COLOR", value-parser = ["always", "auto", "never"], default-value = "auto", num-args = "optional", require-equals = true, default-missing-value = "always", help = "Specify WHEN to colorize output." }

YAML

name: prog
args:
  color:
    long: color
    value-name: COLOR
    value-parser:
    - always
    - auto
    - never
    default-value: auto
    num-args: optional
    require-equals: true
    default-missing-value: always
    help: Specify WHEN to colorize output.

JSON

{
  "name": "prog",
  "args": {
    "color": {
      "long": "color",
      "value-name": "COLOR",
      "value-parser": [
        "always",
        "auto",
        "never"
      ],
      "default-value": "auto",
      "num-args": "optional",
      "require-equals": true,
      "default-missing-value": "always",
      "help": "Specify WHEN to colorize output."
    }
  }
}

Input

prog --color

Output

claptrap_color='always'

Example 4

Spec

TOML

name = "prog"
[args]
create = { long = "create", value-name = "BOOL", value-parser = ":bool:", num-args = "optional", require-equals = true, default-missing-value = "true" }

YAML

name: prog
args:
  create:
    long: create
    value-name: BOOL
    value-parser: ':bool:'
    num-args: optional
    require-equals: true
    default-missing-value: 'true'

JSON

{
  "name": "prog",
  "args": {
    "create": {
      "long": "create",
      "value-name": "BOOL",
      "value-parser": ":bool:",
      "num-args": "optional",
      "require-equals": true,
      "default-missing-value": "true"
    }
  }
}

Input

prog

Output

Example 5

Spec

TOML

name = "prog"
[args]
create = { long = "create", value-name = "BOOL", value-parser = ":bool:", num-args = "optional", require-equals = true, default-missing-value = "true" }

YAML

name: prog
args:
  create:
    long: create
    value-name: BOOL
    value-parser: ':bool:'
    num-args: optional
    require-equals: true
    default-missing-value: 'true'

JSON

{
  "name": "prog",
  "args": {
    "create": {
      "long": "create",
      "value-name": "BOOL",
      "value-parser": ":bool:",
      "num-args": "optional",
      "require-equals": true,
      "default-missing-value": "true"
    }
  }
}

Input

prog --create=false

Output

claptrap_create='false'

Example 6

Spec

TOML

name = "prog"
[args]
create = { long = "create", value-name = "BOOL", value-parser = ":bool:", num-args = "optional", require-equals = true, default-missing-value = "true" }

YAML

name: prog
args:
  create:
    long: create
    value-name: BOOL
    value-parser: ':bool:'
    num-args: optional
    require-equals: true
    default-missing-value: 'true'

JSON

{
  "name": "prog",
  "args": {
    "create": {
      "long": "create",
      "value-name": "BOOL",
      "value-parser": ":bool:",
      "num-args": "optional",
      "require-equals": true,
      "default-missing-value": "true"
    }
  }
}

Input

prog --create

Output

claptrap_create='true'