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8. Other Families of Languages

8.1. FORTH

FORTH is a token-based programming language that involves explicit stack-based programming with (at least) two stacks; beyond that, arguments tend to break out concerning whether or not people should use:

It has been quite popular for use in real time applications, as many implementations provide tiny memory footprints and are well suited for burning ROMs. In addition, the programming model involves building up programs "bottom up" generally using an interactive interpreter, which eases debugging.

8.2. BASIC


8.4. PL/1

This language was promoted by IBM as a combined successor to both COBOL and FORTRAN . It parallels Ada , C++ , and Common Lisp in being a rather complex language the point of which people who truly understood it have been rare commodities. Like them, it offers a perhaps-too-rich set of data structures and control structures.

Note that the pared-down PL/M variant was used to implement the CP/M operating system. And much of Multics was implemented in PL/1.

8.5. SNOBOL and Icon

8.6. Miscellanea

8.7. Regular Expressions

Regular expressions are used to do 'pattern matching.' They are a less general form of "language" than any of the others here, not being able to express the full expressivity of looping, storage, and such, of 'real languages.'

They are fundamentally less powerful than typical languages that are "Turing equivalent;" regular expressions essentially describe (or are described by) finite state automata. They are nonetheless plenty useful, and are what is typically used in compiler tools like yacc to describe the "tokens" in computer languages.

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