values.md

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Value parser

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---

• Built-in types
• Enum types

Since raw command line is a string, a parsing is needed to populate options and arguments with non-string values.

Command line parser supports parsing of any custom types via IValueParser<T>.

You may set a value parser for CliOption<T>/CliRepeatableOption<T>/CliArgument<T>/CliRepeatableArgument<T> with UseParser() methods:

var option2 = parser.Option<MyCustomType>("option")
                    .UseParser(new MyCustomTypeValueParser());

Built-in types

You don't need to set custom value parser if your option have one of the following value types:

• string (obviously)
• bool
• char
• byte
• sbyte
• short
• ushort
• int
• uint
• long
• ulong
• float
• double
• decimal
• DateTime
• any of enum types (see more below)
• array of any of types above (comma-separated)

Enum types

Built-in enum value parser supports few ways to configure parsing.

• If an enum member is annotated with an IgnoreDataMemberAttribute or a CliParserIgnoreAttribute, this enum member won't be parsed.

• If an enum member is annotated with a CliParserMemberAttribute, an attribute's parameter is used as enum member's text format. a CliParserMemberAttribute might be specified multiple times, providing aliases for a enum member.

  No other rules will be applied if at least one CliParserMemberAttribute is defined.

• If an enum member is annotated with a DataMemberAttribute and its Name property is set, then its value is used as enum member's text format.

  No other rules will be applied if a DataMemberAttribute with non-empty Name is defined.

• Otherwise, a enum member's name is used as enum member's text format.

See an example below:

public enum MyEnum
{
    // This enum member won't be parsed
    [IgnoreDataMember]
    IgnoreMe,

    // This enum member won't be parsed either
    [CliParserIgnore]
    IgnoreMeToo,

    // This enum member will be parsed as "Value1`
    Value1,

    // This enum member will be parsed as "V2`
    [DataMember(Name = "V2")]
    Value2,

    // This enum member will be parsed as "Value3`
    [DataMember]
    Value3,

    // This enum member will be parsed as "V4`
    [CliParserMember("V4")]
    Value4,

    // This enum member will be parsed as "V4`
    // Note that CliParserMemberAttribute takes priority
    [CliParserMember("V5")]
    [DataMember(Name = "Not_V5")]
    Value5,
}

Enum value parser is case-insensitive, so it will handle Value1, value1 and VALUE1 as the same value.