Pairs of identifiers

Frequently functions appear in pairs like hOpen and hClose, read and show and so on. Libraries are a lot easier to use if they use a consistent scheme of names for related functions. It is even better if many libraries would share the same scheme. This can be useful both for designing function names and for easy guessing of the counterpart of some function.

Here is a collection of some pairs of identifiers I stumbled on in AmigaOS, MUI, Modula-3, Haskell libraries, and C++ STL. This could be a basis for further discussion.

It would be great if the discussion lead to a more streamlined collection where for instance some duplicates are removed.

Create	Delete
New	Dispose
Construct	Destruct
Alloc	Free
Obtain	Release	Attempt
Lock	UnLock
Procure	Vacate
Forbid	Permit
Disable	Enable
Put	Get
Set	Get
Write	Read
Poke	Peek
Open	Close
Save	Load
Load	UnLoad
Init	Exit
Setup	Cleanup
Show	Hide
Insert	Remove
Add	Rem
Push	Pull
Push	Pop
Start	Stop	Size
Begin	End	Length
First	Last	Number
Head	Tail
Front	Back
Top	Bottom
Fmt	Lex
Input	Output

Discussion

read and show

I think the names read and show in the Prelude of Haskell98 aren't a good choice because the functions can be considered as natural pair but this isn't reflected by their names. Even more read and show sound like some I/O operations which they are not. The choice for the Modula-3 libraries (Lex and Fmt) seems to be more suitable. -- HenningThielemann

trees

I had a nice discussion the other day with someone about the right name for tree nodes and leaves. The constructors I'm using as a result are Branch and Leaf. Anyone feel differently? -- BartMassey

Del

I think 'del' is more natural pair for 'add'. --Evgeny Tarasov