[#parser]
[section Parser]

A ['parser] is a [link metafunction_class template metafunction class] that
takes the following arguments:

* a suffix of the input text, a [link string `string`]
* a [link source_position source position] describing at which position of the
  entire input text the suffix begins at

The function parses a prefix of the input string.
When the parsing is successful, it returns an [link accept `accept`] value.
When there is a parsing error, the parser returns a [link reject `reject`]
value. The [link is_error `is_error`] metafunction can be used to determine
about the result of a parser if it succeeded or failed.

The documentation refers often to the ['result of a parser]. This means that the
parser accepts the input and refers to what [link get_result `get_result`]
returns for the value returned by the parser.

[endsect]