Английская Википедия:FLOW-MATIC
Шаблон:Short description Шаблон:Infobox programming language FLOW-MATIC, originally known as B-0 (Business Language version 0), was the first English-like data processing language. It was developed for the UNIVAC I at Remington Rand under Grace Hopper from 1955 to 1959, and helped shape the development of COBOL.
Development
Hopper had found that business data processing customers were uncomfortable with mathematical notation:[1] Шаблон:Quote In late 1953, she proposed that data processing problems should be expressed using English keywords, but Rand management considered the idea unfeasible. In early 1955, she and her team wrote a specification for such a programming language and implemented a prototype.[2] The FLOW-MATIC compiler became publicly available in early 1958 and was substantially complete in 1959.[3]
Innovations and influence
The Laning and Zierler system was the first programming language to parse algebraic formulae. When Hopper became aware of that language in 1954, it altered the trajectory of her work.[4] FLOW-MATIC was the first programming language to express operations using English-like statements.[3] It was also the first system to distinctly separate the description of data from the operations on it. Its data definition language, unlike its executable statements, was not English-like; rather, data structures were defined by filling in pre-printed forms.[3]
FLOW-MATIC and its direct descendant AIMACO shaped COBOL,[5] which incorporated several of its elements:
- Defining Input & Output Files and printed output in advance, separated into INPUT files, OUTPUT files and (HSP) High Speed Printer outputs. Шаблон:Code; Шаблон:Code; Шаблон:Code .[6]
- Qualification of data-names (Шаблон:Code or Шаблон:Code clause).
- Шаблон:Code clause on file Шаблон:Code operations.
- Figurative constant Шаблон:Code (originally Шаблон:Code, where number of Шаблон:Codes indicated precision).
- Dividing the program into sections, separating different parts of the program. Flow-Matic sections included Шаблон:Code (Environment Division), Шаблон:Code (Data Division), and Шаблон:Code (Procedure Division).
Sample program
A sample FLOW-MATIC program:[7][8]
(Шаблон:Vanchor) INPUT INVENTORY FILE-A PRICE FILE-B ; OUTPUT PRICED-INV FILE-C UNPRICED-INV FILE-D ; HSP D . (Шаблон:Vanchor) COMPARE PRODUCT-NO (A) WITH PRODUCT-NO (B) ; IF GREATER GO TO OPERATION 10 ; IF EQUAL GO TO OPERATION 5 ; OTHERWISE GO TO OPERATION 2 . (Шаблон:Vanchor) TRANSFER A TO D . (Шаблон:Vanchor) WRITE-ITEM D . (Шаблон:Vanchor) JUMP TO OPERATION 8 . (Шаблон:Vanchor) TRANSFER A TO C . (Шаблон:Vanchor) MOVE UNIT-PRICE (B) TO UNIT-PRICE (C) . (Шаблон:Vanchor) WRITE-ITEM C . (Шаблон:Vanchor) READ-ITEM A ; IF END OF DATA GO TO OPERATION 14 . (Шаблон:Vanchor) JUMP TO OPERATION 1 . (Шаблон:Vanchor) READ-ITEM B ; IF END OF DATA GO TO OPERATION 12 . (Шаблон:Vanchor) JUMP TO OPERATION 1 . (Шаблон:Vanchor) SET OPERATION 9 TO GO TO OPERATION 2 . (Шаблон:Vanchor) JUMP TO OPERATION 2 . (Шаблон:Vanchor) TEST PRODUCT-NO (B) AGAINST ; IF EQUAL GO TO OPERATION 16 ; OTHERWISE GO TO OPERATION 15 . (Шаблон:Vanchor) REWIND B . (Шаблон:Vanchor) CLOSE-OUT FILES C ; D . (Шаблон:Vanchor) STOP . (END)
Sample Notes
- Note that this sample includes only the executable statements of the program, the Шаблон:Code section. The record fields Шаблон:Code and Шаблон:Code would have been defined in the Шаблон:Code section, which (as previously noted) did not use English-like syntax.[9]
- Files are referred to by the letter at the end of the FILE-LETTER. Example: FILE-A is referred to later just by A and is for ease of reference in following code.
- Operations are numbered in an unbroken sequence from 0..n and are performed in that order unless a statement to the contrary is reached/made (executed) (JUMP, etc.).
- The highest numbered operation is the one that stops the program.
- A much more detailed overview of FLOW-MATIC is available in the manual entitled, FLOW-MATIC PROGRAMMING SYSTEM[10]
Notes
References
- Hopper, Grace (1978). Keynote Address, History of Programming Languages I. ACM. pp. 16–20. Шаблон:ISBN
- Hopper, Grace (1959). “Automatic programming: Present status and future trends”, Mechanisation of Thought Processes, National Physical Laboratory Symposium 10. Her Majesty's Stationery Office. pp 155–200, cited in Шаблон:Cite tech report
- Sammet, Jean (1969). Programming Languages: History and Fundamentals. Prentice-Hall. p. 316–324. Шаблон:ISBN
- Sammet, Jean (1978). "The Early History of COBOL", History of Programming Languages I. ACM. pp. 199–243. Шаблон:ISBN
- Sperry Rand Corporation (1957) Introducing a New Language for Automatic Programming: Univac Flow-Matic
- Remington Rand Univac a Division of Sperry Rand Corporation (1957). FLOW-MATIC PROGRAMMING SYSTEMFLOW-MATIC_Programming_System_1958.pdf
- ↑ Hopper (1959) p. 198.
- ↑ Hopper (1978) p. 16.
- ↑ 3,0 3,1 3,2 Sammet (1969) p. 316
- ↑ Шаблон:Cite book
- ↑ Sammet (1978) p. 204.
- ↑ Remington Rand Univac a Division of Sperry Rand Corporation (1957). FLOW-MATIC PROGRAMMING SYSTEM p. 30.
- ↑ Sperry Rand (1957) p. 7.
- ↑ Sammet (1969) p. 323.
- ↑ Hopper (1978) p. 18.
- ↑ Remington Rand Univac a Division of Sperry Rand Corporation (1957). FLOW-MATIC PROGRAMMING SYSTEM