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QuoteRef: hehnEC7_1975
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Topic:
function call
Group:
Thesa programming system
Topic:
foreach and for all statements
Topic:
index sequence for array access
Topic:
variable as reference to a value
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builtin functions
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macros
Topic:
enumerated data types
Topic:
set data type
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binding names to variables or expressions
Topic:
object-defined names
Topic:
function syntax by pattern
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references g-h
Topic:
object modification
Topic:
pronoun reference
Topic:
generated variable
Topic:
replacement as setting a reference to a value
Topic:
notation for program clusters
Topic:
accessing a sequence
Topic:
no need for efficiency
Topic:
data record
Topic:
import/export lists for defining an interface
Group:
function
Topic:
function vs. procedure
Topic:
replacement as a procedure call
Topic:
Thesa data model
Group:
program module
Group:
variables
Topic:
constants
Topic:
primitive data types for Thesa
Topic:
Thesa data structures
Topic:
dynamic type checking
Topic:
restricted and extended types
Topic:
data type as a set of values
Topic:
variables as objects which remember a value
Reference
Hehner, E.C.R., "Merlin: Towards an ideal programming language", University of Toronto, Computer Systems Research Group, CSRG-57, July 1975. Google
Notes
from the Ideal language project
2 ;;Quote: Merlin is for the convenient development and clear expression of algorithms, not efficiency QuoteRef: hehnEC7_1975 ;;6 ordered or unordered literal values named by listing eg red, blue, green: v QuoteRef: hehnEC7_1975 ;;8 sequences by a by b to c or A to C QuoteRef: hehnEC7_1975 ;;9 unordered sets by braces around a sequence of values
9 ;;Quote: in Merlin, records by a list of elements with specified indices; a sequence or array uses numbers for indices QuoteRef: hehnEC7_1975 ;;10 "abc" is 1:(a) 2:(b) 3:© where (character literal) QuoteRef: hehnEC7_1975 ;;12 all kinds of set and list operations, standards plus various mapping operations QuoteRef: hehnEC7_1975 ;;15 allows literals such as j: 2*i+1 QuoteRef: hehnEC7_1975 ;;16 variable is literal [another literal, j: 2*i+1] with type value e.g., name: var in sectorlist QuoteRef: hehnEC7_1975 ;;20 assignment by name .larrow. value where type matches QuoteRef: hehnEC7_1975 ;;21 increment by i <- #+1 QuoteRef: hehnEC7_1975 ;;21 standard control functions eg for name in sectorlist QuoteRef: hehnEC7_1975 ;;28 writes example programs very much like language programs [MERLIN] QuoteRef: hehnEC7_1975 ;;28 reference to a labeled statement means do that statement QuoteRef: hehnEC7_1975 ;;39 defining a random variable also defines the variable to implement that random (so don't need a global variable) QuoteRef: hehnEC7_1975 ;;39 random number generator: random: module seed: par in rationals; export variable, generate; seed: ...(this is default value);variable: var in rationals; variable<- seed (initializing code); generate: ...(changes variable) .box. then can say r: random [seed:123] (overrides default seed) and use a locally known variable r.variable ... QuoteRef: hehnEC7_1975 ;;41 module definition eg complex-stack: stack (entries: complex .circlePlus. numbers) c: var in complex .circlePlus. numbers complex-stack .circlePlus. push (entry:c)
41 ;;Quote: modules export names while routines import them QuoteRef: hehnEC7_1975 ;;41 definition of a module defines a set of complex names
42 ;;Quote: a function is an abstraction of a value that is instantiated on execution
42 ;;Quote: a routine is an abstraction of assignment since its execution changes the values of variables
42 ;;Quote: a type module is an abstraction of naming; its execution introduces new names QuoteRef: hehnEC7_1975 ;;45 lots of key words, straightforward pattern matching merlin QuoteRef: hehnEC7_1975 ;;58 "a variable stands for a value"
58 ;;Quote: a constant is a permanent name for a value; a variable is a temporary name
60 ;;Quote: while some operators apply to many types, others apply to restricted types, e.g., division
60 ;;Quote: Merlin defines data type as a set of values
61 ;;Quote: a name corresponds to the initial value of possible changes to a variable QuoteRef: hehnEC7_1975 ;;63 L[5]<- 8 means L<-# replace 5 by 8 i.e. L[5] now stands for a different value
Topic: function call (28 items)
Group: Thesa programming system (11 topics, 561 quotes)
Topic: foreach and for all statements (16 items)
Topic: index sequence for array access (16 items)
Topic: variable as reference to a value (21 items)
Topic: builtin functions (6 items)
Topic: macros (22 items)
Topic: enumerated data types (17 items)
Topic: set data type (16 items)
Topic: binding names to variables or expressions (10 items)
Topic: object-defined names (15 items)
Topic: function syntax by pattern (15 items)
ThesaHelp: references g-h (299 items)
Topic: object modification (10 items)
Topic: pronoun reference (23 items)
Topic: generated variable (7 items)
Topic: replacement as setting a reference to a value (10 items)
Topic: notation for program clusters (4 items)
Topic: accessing a sequence (9 items)
Topic: no need for efficiency (28 items)
Topic: data record (57 items)
Topic: import/export lists for defining an interface (20 items)
Group: function (12 topics, 232 quotes)
Topic: function vs. procedure (9 items)
Topic: replacement as a procedure call (10 items)
Topic: Thesa data model (58 items)
Group: program module (10 topics, 334 quotes)
Group: variables (10 topics, 128 quotes)
Topic: constants (21 items)
Topic: primitive data types for Thesa (82 items)
Topic: Thesa data structures (59 items)
Topic: dynamic type checking (43 items)
Topic: restricted and extended types (34 items)
Topic: data type as a set of values (20 items)
Topic: variables as objects which remember a value (10 items)