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ROSE 0.11.145.328
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Describes one argument of a command-line switch.
A SwitchArgument declares one argument for a switch. Each argument should have a string name that will appear in documentation and error messages. Each argument also has a ValueParser for parsing the argument, and an optional default value to use if the argument is missing (the presence of a default value makes the argument optional). If a default value is specified then it must be parsable by the specified parser.
A SwitchArgument declares only one argument. Some switches may have more than one argument, like --swap a b, in which case their declaration would have two SwitchArgument objects. Some switches take one argument which is a list of values, like --swap a,b, which is described by declaring a single argument with listParser. Some switches may occur multiple times to specify their arguments, like --swap a --swap b, in which case the switch is declared to have one argument and to save a value for each occurrence (see Switch::whichValue).
Users seldom use this class directly, but rather call Switch::argument to declare arguments.
Definition at line 1531 of file Sawyer/CommandLine.h.
#include <Sawyer/CommandLine.h>
Public Member Functions | |
| SwitchArgument (const std::string &name, const ValueParser::Ptr &parser=anyParser()) | |
| Construct a new required argument. | |
| SwitchArgument (const std::string &name, const ValueParser::Ptr &parser, const std::string &defaultValueString) | |
| Construct a new switch optional argument. | |
| bool | isRequired () const |
| Returns true if this argument is required. | |
| bool | isOptional () const |
| Returns true if this argument is not required. | |
| const std::string & | name () const |
| Argument name. | |
| std::string | nameAsText () const |
| Returns the name without markup. | |
| const ParsedValue & | defaultValue () const |
| The parsed default value. | |
| const std::string & | defaultValueString () const |
| The default value string. | |
| const ValueParser::Ptr & | parser () const |
| Returns a pointer to the parser. | |
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explicit |
Construct a new required argument.
The name is used in documentation and error messages and need not be unique.
References Sawyer::CommandLine::anyParser().
| Sawyer::CommandLine::SwitchArgument::SwitchArgument | ( | const std::string & | name, |
| const ValueParser::Ptr & | parser, | ||
| const std::string & | defaultValueString | ||
| ) |
Construct a new switch optional argument.
The name is used in documentation and error messages and need not be unique. The defaultValueString is immediately parsed via supplied parser and stored; an std::runtime_error exception is thrown if it cannot be parsed.
| bool Sawyer::CommandLine::SwitchArgument::isRequired | ( | ) | const |
Returns true if this argument is required.
An argument is a required argument if it has no default value.
| bool Sawyer::CommandLine::SwitchArgument::isOptional | ( | ) | const |
Returns true if this argument is not required.
Any argument that is not a required argument will have a default value that is returned in its place when parsing the switch.
| const std::string & Sawyer::CommandLine::SwitchArgument::name | ( | ) | const |
Argument name.
The name is used for documentation and error messages. It need not look like a variable. For instance, it could be "on|off|auto" to indicate that three values are possible, or "\@v{int}|wide" to indicate that the value can be any integer or the string "wide". The string may contain markup, which is removed when used in error messages. As a convenience, if the string begins with a lower-case letter and contains only lower-case letters, hyphens, and underscores then it will be treated as a variable. That is, the string "foo" is shorthand for "\@v{foo}".
| std::string Sawyer::CommandLine::SwitchArgument::nameAsText | ( | ) | const |
Returns the name without markup.
| const ParsedValue & Sawyer::CommandLine::SwitchArgument::defaultValue | ( | ) | const |
The parsed default value.
The ParsedValue::isEmpty() will return true if this argument is required.
| const std::string & Sawyer::CommandLine::SwitchArgument::defaultValueString | ( | ) | const |
The default value string.
This is the string that was parsed to create the default value. Returns an empty string if the argument is required, but since such values are also valid default values one should call isRequired() or isOptional() to make that determination.
| const ValueParser::Ptr & Sawyer::CommandLine::SwitchArgument::parser | ( | ) | const |
Returns a pointer to the parser.
Parsers are reference counted and should not be explicitly destroyed.
1.9.8