Maintainer	bastiaan.heeren@ou.nl
Stability	provisional
Portability	portable (depends on ghc)
Safe Haskell	None
Language	Haskell98

Ideas.Common.Id

Contents

Constructing identifiers
Accessing (and changing) identifiers
Labeling with identifiers

Description

Many entities of the Ideas framework carry an Id for identification. Identifiers have a hierarchical structure of an arbitrary depth (e.g. algebra.equation or a.b.c). Valid symbols for identifiers are the alpha-numerical characters, together with - and _. Each identifier carries a description and a hash value for fast comparison.

Functionality for identifiers is provided by means of three type classes:

Type class IsId for constructing identifiers
Type class HasId for accessing (and changing) the identifier of an entity. Instances of this type class must always have exactly one identifier (although this identifier can be empty).
Type class Identify for labeling entities with an identifier. Instances of this type class typically allow labels to appear at multiple locations within their structure.

The Id datatype implements and re-exports the Monoid interface.

Synopsis

Constructing identifiers

data Id Source

Abstract data type for identifiers with a hierarchical name, carrying a description. The data type provides a fast comparison implementation.

Instances

Eq Id Source
Data Id Source
Ord Id Source
Read Id Source
Show Id Source
Arbitrary Id Source
Monoid Id Source
HasId Id Source
IsId Id Source

class IsId a where Source

Type class IsId for constructing identifiers. Examples are newId "algebra.equation", newId ("a", "b", "c"), and newId () for the empty identifier.

Minimal complete definition

newId

Methods

newId :: a -> Id Source

concatId :: [a] -> Id Source

Instances

IsId Char Source
IsId () Source
IsId Id Source
IsId a => IsId [a] Source
IsId a => IsId (Maybe a) Source
(IsId a, IsId b) => IsId (Either a b) Source
(IsId a, IsId b) => IsId (a, b) Source
(IsId a, IsId b, IsId c) => IsId (a, b, c) Source

(#) :: (IsId a, IsId b) => a -> b -> Id infixr 8 Source

Appends two identifiers. Both parameters are overloaded.

Accessing (and changing) identifiers

class HasId a where Source

Type classfor accessing (and changing) the identifier of an entity.

Methods

getId :: a -> Id Source

changeId :: (Id -> Id) -> a -> a Source

Instances

HasId Id Source
HasId ViewPackage Source
HasId Symbol Source
HasId Binding Source
HasId Service Source
HasId DomainReasoner Source
HasId (Ref a) Source
HasId (RewriteRule a) Source
HasId (Rule a) Source
HasId (Decl f) Source
HasId (LabeledStrategy a) Source
HasId (Predicate a) Source
HasId (Exercise a) Source
HasId (State a) Source
(HasId a, HasId b) => HasId (Either a b) Source
HasId (Isomorphism a b) Source
HasId (View a b) Source

unqualified :: HasId a => a -> String Source

Get the unqualified part of the identifier (i.e., last string).

qualifiers :: HasId a => a -> [String] Source

Get the list of qualifiers of the identifier (i.e., everything but the last string).

qualification :: HasId a => a -> String Source

Get the qualified part of the identifier. If the identifier consists of more than one part, the parts are separated by a period (.).

describe :: HasId a => String -> a -> a Source

Give a description for the current entity. If there already is a description, both strings are combined.

description :: HasId a => a -> String Source

Get the current description.

showId :: HasId a => a -> String Source

Show the identifier.

compareId :: HasId a => a -> a -> Ordering Source

Compare two identifiers based on their names. Use compare for a fast ordering based on hash values.

Labeling with identifiers

class HasId a => Identify a where Source

Type class for labeling entities with an identifier

Methods

(@>) :: IsId n => n -> a -> a Source

Instances

Identify (Predicate a) Source
Identify (Isomorphism a b) Source
Identify (View a b) Source

module Data.Monoid