Concept
OCaml
Related concepts (27)
Bootstrapping (compilers)
In computer science, bootstrapping is the technique for producing a self-compiling compiler – that is, a compiler (or assembler) written in the source programming language that it intends to compile. An initial core version of the compiler (the bootstrap compiler) is generated in a different language (which could be assembly language); successive expanded versions of the compiler are developed using this minimal subset of the language.
Function object
In computer programming, a function object is a construct allowing an object to be invoked or called as if it were an ordinary function, usually with the same syntax (a function parameter that can also be a function). In some languages, particularly C++, function objects are often called functors (not related to the functional programming concept). A typical use of a function object is in writing callback functions. A callback in procedural languages, such as C, may be performed by using function pointers.
Partial application
In computer science, partial application (or partial function application) refers to the process of fixing a number of arguments to a function, producing another function of smaller arity. Given a function , we might fix (or 'bind') the first argument, producing a function of type . Evaluation of this function might be represented as . Note that the result of partial function application in this case is a function that takes two arguments. Partial application is sometimes incorrectly called currying, which is a related, but distinct concept.
Opa (programming language)
Opa is an open-source programming language for developing scalable web applications. It can be used for both client-side and server-side scripting, where complete programs are written in Opa and subsequently compiled to Node.js on the server and JavaScript on the client, with the compiler automating all communication between the two. Opa implements strong, static typing, which can be helpful in protecting against security issues such as SQL injections and cross-site scripting attacks.
Hack (programming language)
Hack is a programming language for the HipHop Virtual Machine (HHVM), created by Facebook as a dialect of PHP. The language implementation is open-source, licensed under the MIT License. Hack allows programmers to use both dynamic typing and static typing. This kind of a type system is called gradual typing, which is also implemented in other programming languages such as ActionScript. Hack's type system allows types to be specified for function arguments, function return values, and class properties; however, types of local variables are always inferred and cannot be specified.
Short-circuit evaluation
Short-circuit evaluation, minimal evaluation, or McCarthy evaluation (after John McCarthy) is the semantics of some Boolean operators in some programming languages in which the second argument is executed or evaluated only if the first argument does not suffice to determine the value of the expression: when the first argument of the AND function evaluates to false, the overall value must be false; and when the first argument of the OR function evaluates to true, the overall value must be true.
Covariance and contravariance (computer science)
Many programming language type systems support subtyping. For instance, if the type is a subtype of , then an expression of type should be substitutable wherever an expression of type is used. Variance is how subtyping between more complex types relates to subtyping between their components. For example, how should a list of s relate to a list of s? Or how should a function that returns relate to a function that returns ? Depending on the variance of the type constructor, the subtyping relation of the simple types may be either preserved, reversed, or ignored for the respective complex types.