Editing FLOW-MATIC

{{Short description|First English-like data processing language}}
{{Infobox programming language
| name = FLOW-MATIC
| paradigm = [[imperative programming|imperative]]
| year = {{start-date|1955}}
| designer = [[Remington Rand]], [[Grace Hopper]]
| influenced_by = [[ARITH-MATIC]], [[Laning and Zierler system]]
| influenced = [[MATH-MATIC]], [[AIMACO]], [[COBOL]]
| platform = [[UNIVAC I]]
}}
'''FLOW-MATIC''', originally known as '''B-0''' ('''Business Language version 0'''), was the first English-like [[computer data processing|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:<ref>Hopper (1959) p.&nbsp;198.</ref>
{{quote|I used to be a mathematics professor. At that time I found there were a certain number of students who could not learn mathematics. I then was charged with the job of making it easy for businessmen to use our computers. I found it was not a question of whether they could learn mathematics or not, but whether they would. […] They said, 'Throw those symbols out—I do not know what they mean, I have not time to learn symbols.' I suggest a reply to those who would like data processing people to use mathematical symbols that they make the first attempt to teach those symbols to vice-presidents or a colonel or admiral. I assure you that I tried it.|author=|title=|source=}} 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.<ref>Hopper (1978) p.&nbsp;16.</ref> The FLOW-MATIC compiler became publicly available in early 1958 and was substantially complete in 1959.<ref name="sammet316">Sammet (1969) p.&nbsp;316</ref>

== 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.<ref name="Beyer_ch10">{{cite book|last=Beyer|first=Kurt|title=Grace Hopper and the Invention of the Information Age|publisher=MIT Press|date=February 10, 2012|isbn=9780262517263|chapter=10}}</ref> FLOW-MATIC was the first programming language to [[English-like programming language|express operations using English-like statements instead of symbols that have no meaning.]]<ref name="sammet316" /> 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.<ref name="sammet316" />

FLOW-MATIC  and its direct descendant [[AIMACO]] shaped [[COBOL]],<ref>Sammet (1978) p.&nbsp;204.</ref> 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. {{code|INPUT <FILE-NAME> <FILE-LETTER>}}; {{code|OUTPUT <FILE-NAME> <FILE-LETTER>}}; {{code|HSP <FILE-LETTER>}} .<ref>Remington Rand Univac a Division of Sperry Rand Corporation (1957). FLOW-MATIC PROGRAMMING SYSTEM p.&nbsp;30.</ref>
* Qualification of data-names ({{code|IN}} or {{code|OF}} clause).
* {{code|IF END OF DATA (AT END)}} clause on file {{code|READ}} operations.
* Figurative constant {{code|ZERO}} (originally {{code|ZZZ...ZZZ}}, where number of {{code|Z}}s indicated precision).
* Dividing the program into sections, separating different parts of the program.  Flow-Matic sections included '''{{code|Computer}}''' (Environment Division), '''{{code|Directory}}''' (Data Division), and '''{{code|Compiler}}''' (Procedure Division).

== Sample  Code ==
A sample FLOW-MATIC program:<ref>Sperry Rand (1957) p.&nbsp;7.</ref><ref>Sammet (1969) p.&nbsp;323.</ref>
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  ({{vanchor|0}})  INPUT INVENTORY FILE-A PRICE FILE-B ; OUTPUT PRICED-INV FILE-C UNPRICED-INV
      FILE-D ; HSP D .
  ({{vanchor|1}})  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 .
  ({{vanchor|2}})  TRANSFER A TO D .
  ({{vanchor|3}})  WRITE-ITEM D .
  ({{vanchor|4}})  JUMP TO OPERATION 8 .
  ({{vanchor|5}})  TRANSFER A TO C .
  ({{vanchor|6}})  MOVE UNIT-PRICE (B) TO UNIT-PRICE (C) .
  ({{vanchor|7}})  WRITE-ITEM C .
  ({{vanchor|8}})  READ-ITEM A ; IF END OF DATA GO TO OPERATION 14 .
  ({{vanchor|9}})  JUMP TO OPERATION 1 .
 ({{vanchor|10}})  READ-ITEM B ; IF END OF DATA GO TO OPERATION 12 .
 ({{vanchor|11}})  JUMP TO OPERATION 1 .
 ({{vanchor|12}})  SET OPERATION 9 TO GO TO OPERATION 2 .
 ({{vanchor|13}})  JUMP TO OPERATION 2 .
 ({{vanchor|14}})  TEST PRODUCT-NO (B) AGAINST ; IF EQUAL GO TO OPERATION 16 ;
      OTHERWISE GO TO OPERATION 15 .
 ({{vanchor|15}})  REWIND B .
 ({{vanchor|16}})  CLOSE-OUT FILES C ; D .
 ({{vanchor|17}})  STOP . (END)

Sample Notes
# Note that this sample includes only the executable statements of the program, the {{code|COMPILER}} section. The record fields {{code|PRODUCT-NO}} and {{code|UNIT-PRICE}} would have been defined in the {{code|DIRECTORY}} section, which ([[FLOW-MATIC#Innovations and influence|as previously noted]]) did not use English-like syntax.<ref>Hopper (1978) p.&nbsp;18.</ref>
# 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 titled, FLOW-MATIC PROGRAMMING SYSTEM<ref>Remington Rand Univac a Division of Sperry Rand Corporation (1957). FLOW-MATIC PROGRAMMING SYSTEM</ref>

== Notes ==
{{Reflist|30em}}

== References ==
{{refbegin}}
* Hopper, Grace (1978). Keynote Address, ''[http://portal.acm.org/citation.cfm?id=800025 History of Programming Languages I]''. ACM. pp.&nbsp;16–20. {{ISBN|0-12-745040-8}}
* 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 {{cite tech report
|first1=Donald|last1=Knuth
|first2=Luis|last2=Trabb Pardo
|title=The Early Development of Programming Languages
|date=August 1976
|publisher=Computer Science Department, School of Humanities and Sciences, Stanford University
|url=https://archive.org/details/DTIC_ADA032123/page/n29
|access-date=2016-03-19
}}
* Sammet, Jean (1969). ''Programming Languages: History and Fundamentals''. Prentice-Hall. p.&nbsp;316–324. {{ISBN|0-13-729988-5}}
* Sammet, Jean (1978). "The Early History of COBOL", ''[http://portal.acm.org/citation.cfm?id=800025 History of Programming Languages I]''. ACM. pp.&nbsp;199–243. {{ISBN|0-12-745040-8}}
* Sperry Rand Corporation (1957) ''[https://web.archive.org/web/20130702225747/http://www.computerhistory.org/collections/accession/102646140 Introducing a New Language for Automatic Programming: Univac Flow-Matic]''
* Remington Rand Univac a Division of Sperry Rand Corporation (1957). FLOW-MATIC PROGRAMMING SYSTEM''[http://www.bitsavers.org/pdf/univac/flow-matic/U1518_FLOW-MATIC_Programming_System_1958.pdf FLOW-MATIC_Programming_System_1958.pdf]''
{{refend}}

{{DEFAULTSORT:Flow-Matic}}
[[Category:Procedural programming languages]]
[[Category:COBOL]]
[[Category:Programming languages created in 1955]]