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## QuoteRef: landPJ_1966

topics > all references > ThesaHelp: references i-l

Topic:
evaluation in an environment
Topic:
notations for brackets
Topic:
data type as constructors, selectors, and predicates
ThesaHelp:
references i-l
Topic:
lists
Topic:
recursion
Topic:
function application
Topic:
parameters as argument place holders
Topic:
lambda calculus
Topic:
names defined by context
Topic:
security by access functions
Topic:
state machine

#### Reference

Landin, P.J., "A .lambda.-calculus approach", pp. 97-141, in Fox, L. (ed.), Advance in programming and non-numerical computation, Oxford, England, Pergamon Press, 1966. Google

#### Other Reference

QuoteRef: landPJ1_1964

#### Notes

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Quotations
 QuoteRef: landPJ_1966 ;;98 basic form: application expressions (AE) QuoteRef: landPJ_1966 ;;101 operator/operand form or expressions shows "applicative structure QuoteRef: landPJ_1966 ;;103 (lambda arg list expression)(operand) 104 ;;Quote: a bound variable or parameter is symbol independent, while a free variable depends on context QuoteRef: landPJ_1966 ;;105 all brackets same effect, intermix for clarity QuoteRef: landPJ_1966 ;;108 AE is an id, a lambda expression (bound variable part and lambda body-AE) or a combination (operator-AE and operand-AE parts) QuoteRef: landPJ_1966 ;;108 on AE's have predicates for each type (ed identifier (x) == true) selectors for each component (eg lambda body (lambda x.x+1) == x+1 constructors for each type (eg constructlambda (x, x+1) QuoteRef: landPJ_1966 ;;112 List has null predicate and head and tail selectors 114 ;;Quote: prevent division by zero in unused branch by using access functions to delay execution QuoteRef: landPJ_1966 ;;116 recursive functions: functions= AE-without-function [function as operand] the function is the fixed point of the AE (x=Fx) so the fixed-point function Y makes non-recursive i.e. x=YF QuoteRef: landPJ_1966 ;;116 factorial: f= Y lambda f. lambda n. if n=0 then 1 else n* f(n-1) QuoteRef: landPJ_1966 ;;120 each AE a value within an environment (value of free variables) QuoteRef: landPJ_1966 ;;121 value of id is environment applied to id (val(e)(x)==e(x) value of combination is combination of value of parts value of lambda expression is a function with a bound variable derived environment. QuoteRef: landPJ_1966 ;;122 mechanical evaluation: layered environment of paired id and value list where val(e) (x) is (location e**2 x) e**2 QuoteRef: landPJ_1966 ;;122 value of a lambda expression is a "closure" of environment part (environment with bound id list) and control part (a lambda body) 123 ;;Quote: mechanical evaluation of state machine; current state is stack of temporaries, environment, control, and dump

Related Topics

Topic: evaluation in an environment (34 items)
Topic: notations for brackets (9 items)
Topic: data type as constructors, selectors, and predicates (20 items)
ThesaHelp: references i-l (342 items)
Topic: lists (7 items)
Topic: recursion (16 items)
Topic: function application (18 items)
Topic: parameters as argument place holders (15 items)
Topic: lambda calculus (14 items)
Topic: names defined by context (36 items)
Topic: security by access functions (10 items)
Topic: state machine (67 items)

Collected barberCB 1980