Interface description language

An interface description language or interface definition language (IDL), is a specification language used to describe a software component's application programming interface (API). IDLs describe an interface in a language-independent way, enabling communication between software components that do not share one language. For example, between those written in C++ and those written in Java.

IDLs are commonly used in remote procedure call software. In these cases the machines at either end of the link may be using different operating systems and computer languages. IDLs offer a bridge between the two different systems.

Software systems based on IDLs include Sun's ONC RPC, The Open Group's Distributed Computing Environment, IBM's System Object Model, the Object Management Group's CORBA (which implements OMG IDL, an IDL based on DCE/RPC), Mozilla's XPCOM, Facebook's Thrift and WSDL for Web services.

Examples

IDL

IDL may refer to:

Computing

IDL (programming language)

IDL, short for Interactive Data Language, is a programming language used for data analysis. It is popular in particular areas of science, such as astronomy, atmospheric physics and medical imaging. IDL shares a common syntax with PV-Wave and originated from the same codebase, though the languages have subsequently diverged in detail. There are also two free implementations, GNU Data Language (GDL) and Fawlty Language (FL).

Overview

IDL is vectorized, numerical, and interactive, and is commonly used for interactive processing of large amounts of data (including image processing). The syntax includes many constructs from Fortran and some from C.

IDL originated from early VAX/VMS/Fortran, and its syntax still shows its heritage:

The findgen function in the above example returns a one-dimensional array of floating point numbers, with values equal to a series of integers starting at 0.

Note that the operation in the second line applies in a vectorized manner to the whole 100-element array created in the first line, analogous to the way general-purpose array programming languages (such as APL, J or K) would do it. This example contains a divide by zero; IDL will report an arithmetic overflow, and store a NaN value in the corresponding element of the y array (the first one), but the other array elements will be finite. The NaN is excluded from the visualization generated by the plot command.