Statements and Expressions

• Introduction
• Starting, Interrupting, and Terminating
  • <Ctrl>-C
  • quit;
  • <Ctrl>-D
  • <Ctrl>-\
• Identifiers
• Assignment
  • Simple Assignment
    • x := expression;
    • Example: Identifiers and Intrinsic Names
    • x₁, x₂, ..., xₙ := expression;
    • _ := expression;
    • assigned x: Var → BoolElt
    • Example: Multiple Return Values
  • Indexed Assignment
    • x[expr₁][expr₂]...[exprₙ] := expression;
    • x[expr₁,expr₂,...,exprₙ] := expression;
    • Example: Modifying Nested Sequence Entries
  • Generator Assignment
    • E<x₁, x₂, ...xₙ> := expression;
    • E<[x]> := expression;
    • Example: Naming Generators with a Sequence
    • AssignNames(~S, [s₁, ... sₙ] ): Str, [ MonStgElt ]
    • Example: Renaming Group Generators
  • Mutation Assignment
    • x o:= expression;
    • Example: Mutation Assignment
  • Deletion of Values
    • delete x: Var
• Boolean Values
  • Creation of Booleans
    • Booleans() → Bool
    • # B: Bool → RngIntElt
    • true
    • false
    • 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: Any, Any → BoolElt
    • x ne y: Any, Any → BoolElt
    • x cmpeq y: Any, Any → BoolElt
    • x cmpne y: Any, Any → BoolElt
    • Example: Semantics of Equality Operators
  • Iteration
    • Example: Iterating over the Booleans
• Coercion
  • S ! x: Str, Elt → Elt
  • IsCoercible(S, x): Str, Elt → Bool, Elt
• The where … is Construction
  • expression₁ where identifier is expression₂
  • expression₁ where identifier := expression₂
  • Example: Local Bindings with Where
• Conditional Statements and Expressions
  • The Simple Conditional Statement
    • if
    • if
    • elif
    • Example: A Simple Conditional Statement
  • The Simple Conditional Expression
    • Boolean expression select expr₁ else expr₂
    • Example: Inline Conditional Expressions
  • The Case Statement
    • case expr : when exprᵢ : statements end case
    • Example: Case Statement on a Sign
  • The Case Expression
    • case< expr | expr_left,1 : expr_right,1, ..., expr_left,n : expr_right,n, default : expr_def>
• Error Handling Statements
  • The Error Objects
    • Error(x): Any → Err
    • e`Position: Err → MonStgElt
    • e`Traceback: Err → MonStgElt
    • e`Object: Err → Any
    • e`Type: Err → MonStgElt
  • Error Checking and Assertions
    • error expression, ..., expression;
    • error if Boolean expression, expression, ..., expression;
    • assert Boolean expression;
    • assert2 Boolean expression;
    • assert3 Boolean expression;
  • Catching Errors
    • try statements catch e statements end try
    • Example: Error Objects and Try-Catch
• Iterative Statements
  • Definite Iteration
    • for i := expr₁ to expr₂ by expr₃ do
    • for i := expr₁ to expr₂ do
    • for
  • Indefinite Iteration
    • while
    • Example: Collatz Iteration with a While Loop
    • repeat
    • Example: Collatz Steps with a Repeat Loop
    • for random
  • Dual Iteration
    • for
    • for random
  • Early Exit from Iterative Statements
    • continue;
    • continue identifier;
    • break;
    • break identifier;
    • Example: Breaking Out of Nested Loops
• Runtime Evaluation: the eval Expression
  • eval expression
  • Example: Basic Use of Eval
  • Example: Building Objects with Eval
• Comments and Continuation
  • //
  • /*  */
  • \
  • Example: Comments and Line Continuation
• Timing
  • Cputime() → FldReElt
  • Cputime(t): FldReElt → FldReElt
  • Realtime() → FldReElt
  • Realtime(t): FldReElt → FldReElt
  • ClockCycles() → RngIntElt
  • Time() → MonStgElt
  • Time(T): MonStgElt → MonStgElt
  • time statement;
  • vtime flag: statement;
  • vtime flag, n: statement:
  • SetShowRealTime(v): BoolElt
  • GetShowRealTime() → BoolElt
  • Example: Timing a Factorisation
  • Example: Timing Multithreaded Computations
• Types, Category Names, and Structures
  • Type(x): Elt → Cat
  • Category(x): Elt → Cat
  • ExtendedType(x): Elt → ECat
  • ExtendedCategory(x): Elt → ECat
  • ISA(T, U): Cat, Cat → BoolElt
  • ISA(T, U): Cat, ECat → BoolElt
  • ISA(T, U): ECat, Cat → BoolElt
  • ISA(T, U): ECat, ECat → BoolElt
  • BaseType(T): ECat → Cat
  • # T: ECat → RngIntElt
  • T[i]: ECat, RngIntElt → .
  • Example: Extended Type Accessors
  • MakeType(S): MonStgElt → Cat
  • ElementType(S): Str → Cat
  • CoveringStructure(S, T): Str, Str → Str
  • ExistsCoveringStructure(S, T): Str, Str → BoolElt, Str
  • Example: Type and Structure Functions
• Random Object Generation
  • SetSeed(s, c): RngIntElt, RngIntElt
  • SetSeed(s): RngIntElt
  • GetSeed() → RngIntElt, RngIntElt
  • Random(S): Str → Elt
  • Random(a, b): RngIntElt, RngIntElt → RngIntElt
  • Random(b): RngIntElt → RngIntElt
  • Example: Restoring a Random State
• Miscellaneous
  • IsIntrinsic(S): MonStgElt → Bool, Intrinsic
  • Example: Checking Whether a Name Is Intrinsic
• Bibliography