.\" This man page is automatically generated using .\" kayadoc2man from the Kaya development tools and the -xmldocs compile .\" option. Editing it directly is not encouraged. .\" It is under the same license as the source .k file that it was .\" generated from. .TH "Prelude.Maybe" "3kaya" "August 2014" "Kaya" "Kaya module reference" .SH "NAME" Prelude::Maybe \- Optional values. .SH "SYNOPSIS" .B Prelude::Maybe< \fIa\fP .B > .IP "" -2 = .BI "nothing(" "" ")" .IP "" -2 | .BI "just(" "a val" ")" .SH "DESCRIPTION" .PP A value is either of type \fBa \fP , represented as \fBjust(a) \fP , or empty. Maybe is often useful for computations which can possibly fail, for example looking up values in a dictionary. Because the \fBnothing \fP value can be stored, this is often more useful than Exceptions on failure. .SH "AUTHORS" Kaya standard library by Edwin Brady, Chris Morris and others (kaya@kayalang.org). For further information see http://kayalang.org/ .SH LICENSE The Kaya standard library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (version 2.1 or any later version) as published by the Free Software Foundation. .SH "RELATED" .PD 0 .PP .B "Prelude.deref"(3kaya) .PP .B "Dict.lookup"(3kaya) .PD 0.4v