The Associative Programming Language (APL) is a

database language In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and analy ...

developed by

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in 1966. APL was developed to provide

high-level language A high-level programming language is a programming language with strong abstraction from the details of the computer. In contrast to low-level programming languages, it may use natural language ''elements'', be easier to use, or may automate (or ...

data access and manipulation functions to support GM's CADANCE interactive

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system. It was designed to integrate with

PL/I PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language initially developed by IBM. It is designed for scientific, engineering, business and system programming. It has b ...

. The underlying database is assumed to follow the

network model In computing, the network model is a database model conceived as a flexible way of representing objects and their relationships. Its distinguishing feature is that the schema, viewed as a graph in which object types are nodes and relationship ty ...

. GM's first database manager was implemented via

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s, but in 1977 the "Virtual Associative Access Manager" {VAAM) was developed to use virtual storage and implementing entity relationships as arrays. APL was later ported to the MCTS operating system.

Description

APL consists of six statements, CREATE, INSERT, FIND, FOR EACH, REMOVE, and DELETE, and miscellaneous functions such as counting the number of members in a set, determining the length or type of an entity, or locating an entity by name. * Create is a synonym for Allocate. It causes storage to be allocated for a based variable. A file or set where the data is to be allocated may be specified. * Delete is a synonym for Free. Delete frees a based variable and optionally removes it from all sets of which it is a member. * Find locates an entity that is a member of a set or container based on specified conditions. An optional ELSE clause is executed if no entities are found. * For Each heads a group of statements to be executed for all entities or sets matching a specified condition. * Insert inserts an entity into a specified set. Optionally, the placement of the new entity relative to other elements of the set may be specified. * Let sets a locator variable to reference a specified set. * Remove removes an entity from a set.

Implementation

APL statements were implemented as PL/I preprocessor macros, which translated into calls to the database manager. Later GM's

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PL/I dialect supported APL directly in the language.

References

{{Reflist Query languages General Motors