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Topic: no need for variables
topics >
computer science >
data >
naming
Topic:
calculator
Topic:
curried functions
Topic:
definition languages
Topic:
immutable files and data
Topic:
list processing
Topic:
no need for replacement
Topic:
reduction languages
Topic:
reduction machines
Summary
A number of languages do away with variables altogether. Examples are machine code, COMIT which uses a workspace for computation, reduction languages, definitional languages, and calculators. Variables are replaced by access functions, curried functions, macros, or temporaries. For instance the variables 'x' and 'y' in a function definition for 'succ (x)':
declare function succ (x:integer):integer; begin declare integer y; y := x + 1; return y; end;can be removed by the curried function
'plus 1': declare function succ := plus 1;Without variables the system's state can not be differentiated into components, instead the state is treated as a whole. (cbb 5/80)
Subtopic: use macros instead of variables
Quote: while a programming language uses names, state machine semantics do not [»backJ_1972, OK]
Subtopic: children do not use variables
Quote: a powerful macro processor can use macros in place of character variables [»browPJ_1969] Quote: instead of parameters, a macro can use its left and right context; arbitrary modifications (search outward from call) [»granCA12_1971, OK]
Subtopic: functional program instead of variables
Quote: found children did not use variables, so removed assignments and variables; kept parameter passing, parameters, and an input variable [»mckeRM5_1984]
Subtopic: global state instead of variables
Quote: a functional program for matrix multiply does not name its parameters or intermediate results Quote: a functional program for matrix multiply contains no variables, no loops, no control statements, no initializations, no declarations
Subtopic: examples
Quote: AST systems can retrieve the whole state, retrieve the definition of a function, or compute the new state [»backJ8_1978a]
QuoteRef: backJ_1972 ;;11 red languages have no variables QuoteRef: sammJE_1969 ;;423 no variables, have a workspace and several shelves QuoteRef: turnDA1_1979 ;;33 x Given: "'def suc x= x+1 The aim is to eliminate the variable x obtaining a definition of the form ... 'def suc = 'plus 1. Quote: if variables are place holders then problems with self-reference and aliasing [»backJ_1972, OK] QuoteRef: sammJE_1969 ;;443 snobol has named string reference while comit has only workspace QuoteRef: sammJE_1969 ;;453 example #(ds, n, ##(cl,n)#(da)) calls n into working area, deletes all forms (da) then defines form n as original without segment gaps
Group: naming (32 topics, 789 quotes)
Topic: calculator (1 item)
Topic: curried functions (14 items)
Topic: definition languages (3 items)
Topic: immutable files and data (59 items)
Topic: list processing (15 items)
Topic: no need for replacement (4 items)
Topic: reduction languages (17 items)
Topic: reduction machines
(14 items)