Digraph (computing)

Digraphs are two-character sequences used to enter single conceptual characters that cannot be entered from the computer keyboard for various reasons: obsolete keyboard, input of special characters is required, the text editor reserves some characters for special use, etc. Digraphs can also be used to extend the keyboard.

Different systems have different sets of defined digraphs.

C programming language supports digraphs in ISO C 94 mode of compiling.
Pascal programming language supports digraphs (., .), (* and *) for [, ], { and } respectively.
Vim text editor uses digraphs.
GNU Screen has a digraph command, bound to ^A ^V by default.
The J programming language uses dot and colon characters to extend the meaning of the basic characters available.
Mobile phones have introduced digraph (and multi-graph) sequences into the English lexicon via Short message service messaging. Emoticons, such as :) appear in modern English language dictionaries.

Digraph Operators in Perl

Digraph Operators are operators that are represented by two symbols. Perl uses the following digraphs:

Shift Operators

<< doubleopenbeak >> doubleclosedbeak

Nudge Operators

++ plusplus -- doubledash

Arithmetic Combination Assignment Operators

+= addition -= subtraction *= multiplication /= division %= modulus

String Manipulation Combination Assignment Operators

x= repetition .= concatenation

Bitwise Combination Assignment Operators

|= BWOR &= BWAND ^= BWXOR