HaskellHaskell (ˈhæskəl) is a general-purpose, statically-typed, purely functional programming language with type inference and lazy evaluation. Designed for teaching, research, and industrial applications, Haskell has pioneered a number of programming language features such as type classes, which enable type-safe operator overloading, and monadic input/output (IO). It is named after logician Haskell Curry. Haskell's main implementation is the Glasgow Haskell Compiler (GHC).
Identifier (computer languages)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. Which character sequences constitute identifiers depends on the lexical grammar of the language.
Sigil (computer programming)In computer programming, a sigil (ˈsɪdʒəl) is a symbol affixed to a variable name, showing the variable's datatype or scope, usually a prefix, as in foo,where is the sigil. Sigil, from the Latin sigillum, meaning a "little sign", means a sign or image supposedly having magical power. Sigils can be used to separate and demarcate namespaces that possess different properties or behaviors. The use of sigils was popularized by the BASIC programming language. Directive (programming)In computer programming, a directive or pragma (from "pragmatic") is a language construct that specifies how a compiler (or other translator) should process its input. Directives are not part of the grammar of a programming language, and may vary from compiler to compiler. They can be processed by a preprocessor to specify compiler behavior, or function as a form of in-band parameterization. In some cases directives specify global behavior, while in other cases they only affect a local section, such as a block of programming code.
Reserved wordIn a computer language, a reserved word (also known as a reserved identifier) is a word that cannot be used as an identifier, such as the name of a variable, function, or label – it is "reserved from use". This is a syntactic definition, and a reserved word may have no user-defined meaning. A closely related and often conflated notion is a keyword, which is a word with special meaning in a particular context. This is a semantic definition. By contrast, names in a standard library but not built into a language are not considered reserved words or keywords.
