Search results
Results from the WOW.Com Content Network
If a symbol is unknown, the Lisp reader creates a new symbol. In Common Lisp, symbols have the following attributes: a name, a value, a function, a list of properties and a package. [6] In Common Lisp it is also possible that a symbol is not interned in a package. Such symbols can be printed, but when read back, a new symbol needs to be created.
Some programming languages restrict operator symbols to special characters like + or := while others allow also names like div (e.g. Pascal). Most languages have a built-in set of operators, but do not allow user-defined operators, as this significantly complicates parsing.
All logical operators exist in C and C++ and can be overloaded in C++, albeit the overloading of the logical AND and logical OR is discouraged, because as overloaded operators they behave as ordinary function calls, which means that both of their operands are evaluated, so they lose their well-used and expected short-circuit evaluation property ...
In computer programming languages, an identifier is a lexical token (also called a symbol, but not to be confused with the symbol primitive data type) that names the language's entities. Some of the kinds of entities an identifier might denote include variables, data types, labels, subroutines, and modules.
Parse tree of Python code with inset tokenization. The syntax of textual programming languages is usually defined using a combination of regular expressions (for lexical structure) and Backus–Naur form (a metalanguage for grammatical structure) to inductively specify syntactic categories (nonterminal) and terminal symbols. [7]
The following table lists many common symbols, together with their name, how they should be read out loud, and the related field of mathematics. Additionally, the subsequent columns contains an informal explanation, a short example, the Unicode location, the name for use in HTML documents, [1] and the LaTeX symbol.
HTML and XML provide ways to reference Unicode characters when the characters themselves either cannot or should not be used. A numeric character reference refers to a character by its Universal Character Set/Unicode code point, and a character entity reference refers to a character by a predefined name.
In Elixir, sigils are provided via the "~" symbol, followed by a letter to denote the type of sigil, and then delimiters. For example, ~r(foo) is a regular expression of "foo". Other sigils include ~s for strings and ~D for dates. Programmers can also create their own sigils. [5]