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vendor/maunium.net/go/mauflag/README.md

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+# mauflag
+[![Build Status](http://img.shields.io/travis/tulir293/mauflag.svg?style=flat-square)](https://travis-ci.org/tulir293/mauflag)
+[![License](http://img.shields.io/:license-gpl3-blue.svg?style=flat-square)](http://www.gnu.org/licenses/gpl-3.0.html)
+
+An extendable argument parser for Golang. Mostly follows the GNU [Program Argument Syntax Conventions](https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html).
+
+Use `go get maunium.net/go/mauflag` to get this package
+
+## Basic usage
+A flag can have as many long or short keys as you like. Short keys are prefixed with one dash (`-`) whilst long keys are prefixed with two (`--`)
+
+To create a flag, you must first call the `Make()` method in a flagset. Calling flagset methods as package functions uses the default flagset which takes input arguments from `os.Args`
+
+After creating a flag, you can call the functions it has as you like. After configuring the flag, you can call one of the type functions to set the flag type and get a pointer to the value.
+
+### Examples
+Here's a basic string flag that can be set using `-s` or `--my-string-flag`
+```go
+var myStringFlag = flag.Make().ShortKey("s").LongKey("my-string-flag").Default("a string").String()
+```
+
+The following input arguments would set the value of the flag to `foo`
+* `-s`, `foo`
+* `-s=foo`
+* `-sfoo`
+* `--my-string-flag`, `foo`
+* `--my-string-flag=foo`
+
+#### Chaining
+Short boolean flags can be chained. The last flag of a chain doesn't necessarily have to be a boolean flag.
+For example, if we had the following flags defined
+```go
+var boolA = flag.Make().ShortKey("a").Bool()
+var boolB = flag.Make().ShortKey("b").Bool()
+var boolC = flag.Make().ShortKey("c").Bool()
+var stringD = flag.Make().ShortKey("d").String()
+```
+We could set the values of all the boolean flags to true with one input argument: `-abc`. We could also add the `d` flag to the end like so: `-abcd`, `foo`.
+Any of the other ways to set short flags also work (`-abcd=foo`, `-abcdfoo`).
+
+However, if you put `d` as the first flag (`-dabc`) the value of the `d` flag will be `abc` and none of the boolean flags would change.
+
+### Godoc
+More docs, including all values supported by default, can be found from [godoc.org/maunium.net/go/mauflag](https://godoc.org/maunium.net/go/mauflag)
+
+## Custom values
+All value containers must implement the `Value` interface. It contains two functions:
+* `Set(string)` which is called whenever the parser finds a value associated with the flag.
+* `Name()` which should return a human-readable name for the type of the value. If the value container contains multiple actual values, `Name()` should return the name of a single object (e.g. `integer` if the value container contains multiple integers)
+
+After creating a value container you can use it by calling the `Custom` method of a `Flag` and giving an instance of the value container. The parser will then call the `Set` method each time it encounters a value associated with the flag.