STATEMENTS AND EXPRESSIONS

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STATEMENTS AND EXPRESSIONS

Introduction

Starting, Interrupting and Terminating

Identifiers

Assignment
Simple Assignment
Indexed Assignment
Generator Assignment
Mutation Assignment
Deletion of Values

Boolean values
Creation of Booleans
Boolean Operators
Equality Operators
Iteration

Coercion

The where ... is Construction

Conditional Statements and Expressions
The Simple Conditional Statement
The Simple Conditional Expression
The Case Statement
The Case Expression
Error Checking and Assertions

Iterative Statements
Definite Iteration
Indefinite Iteration
Early Exit from Iterative Statements

Comments and Continuation

Timing

Types, Category Names and Structures

Random Object Generation

Miscellaneous

Bibliography

DETAILS

Introduction

Starting, Interrupting and Terminating
<Ctrl>-C
quit;
<Ctrl>-\

Identifiers

Simple Assignment
x := expression;
Example State_Identifiers (H1E1)
x_1, x_2, ..., x_n := expression;
_ := expression;
assigned x : Var -> BoolElt
Example State_MultipleReturns (H1E2)

Indexed Assignment
x[expr_1][expr_2]...[expr_n] := expression;
Example State_Indexing (H1E3)

Generator Assignment
E<x_1, x_2, ...x_n> := expression;
E<[x]> := expression;
Example State_GeneratorNamingSequence (H1E4)
AssignNames(~S, [s_1, ... s_n] ) : Struct, [ MonStgElt ] ->
Example State_GeneratorNaming (H1E5)

Mutation Assignment
x o:= expression;
Example State_MutationAssignment (H1E6)

Deletion of Values
delete x : Var; -> Nil

Boolean values

Creation of Booleans
Booleans() : Nil -> Bool
# B : Bool -> RngIntElt
true
Random(B) : Bool -> BoolElt

Boolean Operators
x and y : BoolElt, BoolElt -> BoolElt
x or y: BoolElt, BoolElt -> BoolElt
x xor y: BoolElt, BoolElt -> BoolElt
not x : BoolElt -> BoolElt

Equality Operators
x eq y : Elt, Elt -> BoolElt
x ne y : Elt, Elt -> BoolElt
x cmpeq y : Elt, Elt -> BoolElt
x cmpne y : Elt, Elt -> BoolElt
Example State_Equality (H1E7)

Iteration
Example State_Booleans (H1E8)

Coercion
S ! x : Str, Elt -> Elt
IsCoercible(S, x) : Str, Elt -> Bool, Elt

The where ... is Construction
expression_1 where identifier is expression_2
Example State_where (H1E9)

Conditional Statements and Expressions

The Simple Conditional Statement
if boolexpr_1 then statements_1 else statements_2 end if : ->
Example State_if (H1E10)

The Simple Conditional Expression
Example State_InLineConditional (H1E11)

The Case Statement
case expr : when expr_i : statements end case : ->
Example State_case (H1E12)

The Case Expression
case< | > : ->

Error Checking and Assertions
error expression, ..., expression;
error if boolexpr, expression, ..., expression;
assert boolexpr;

Iterative Statements

Definite Iteration
for i := expr_1 to expr_2 by expr_3 do : ->
for i := expr_1 to expr_2 do : ->

Indefinite Iteration
while boolexpr do statements end while : ->
Example State_while (H1E13)
repeat statements until boolexpr : ->
Example State_repeat (H1E14)

Early Exit from Iterative Statements
Example State_break (H1E15)

Comments and Continuation
//
/* */
\
Example State_Various (H1E16)

Timing
Cputime() : -> FldReElt
Cputime(t) : FldReElt -> FldReElt
Realtime() : -> FldReElt
Realtime(t) : FldReElt -> FldReElt
time statement;
vtime flag: statement;
Example State_Time (H1E17)

Types, Category Names and Structures
Type(x) : Elt -> BoolElt
ISA(T, U) : Cat, Cat -> BoolElt
MakeType(S) : MonStgElt -> Cat
ElementType(S) : Str -> Cat
CoveringStructure(S, T) : Str, Str -> Str
ExistsCoveringStructure(S, T) : Str, Str -> BoolElt, Str
Example State_TypeStructures (H1E18)

Random Object Generation
SetSeed(s, c) : RngIntElt ->
GetSeed() : -> RngIntElt, RngIntElt
Random(S) : Str -> Elt
Random(a, b) : RngIntElt, RngIntElt -> RngIntElt
Random(b) : RngIntElt -> RngIntElt
Example State_IsIntrinsic (H1E19)

Miscellaneous
IsIntrinsic(S) : MonStgElt -> Bool, Intrinsic

Bibliography