Functions

Functions can be declared alongside other declarations. The syntax for functions is defined by the grammar for Function:

Function        ::= [Type] [ID] '(' [Parameters] ')' Block 
Block           ::= '{' LocalDeclaration* Statement* '}'
LocalDeclation  ::= TypeDeclaration | VariableDeclaration
Statement       ::= Block
                 | ';'
                 |  [Expression] ';'
                 |  ForLoop
                 |  Iteration
                 |  WhileLoop 
                 |  DoWhileLoop 
                 |  IfStatement 
                 |  ReturnStatement

ForLoop	        ::= 'for' '(' [Expression] ';' [Expression] ';' [Expression] ')' Statement 
Iteration       ::= 'for' '(' [ID] ':' [Type] ')' Statement
WhileLoop       ::= 'while' '(' [Expression] ')' Statement
DoWhile         ::= 'do' Statement 'while' '(' [Expression] ')' ';'
IfStatment      ::= 'if' '(' [Expression] ')' Statement [ 'else' Statement ]
ReturnStatement ::= 'return' [ [Expression] ] ';'

Functions

The declarations inside functions include only variable and type declarations. Nested function declarations and recursion are not supported.

Iteration

The keyword for has two uses: the first is a C/C++/Java like for-loop, and the second is a Java like iterator or ranged-loop in C++. The second is primarily used to iterate over arrays indexed by scalars.

A statement for (ID : Type) Statement will execute Statement once for each value ID of the domain of type Type. The scope of ID is bound to the Statement, and Type must be a bounded integer or a scalar set.

Examples

add

The following function returns the sum of two integers. The arguments are call by value.

int add(int a, int b)
{
    return a + b; 
}

swap

The following procedure swaps the values of two call-by-reference integer parameters.

void swap(int &a, int &b) 
{
  int c = a;
  a = b;
  b = c;
}

initialize

The following procedure initializes an array such that each element contains its index in the array. Notice that the an array parameter is a call-by-value parameter unless an ampersand is used in the declaration. This is different from C++ syntax, where the parameter could be considered an array of references to integer.

void initialize(int& a[10])
{
  for (i : int[0,9]) 
  {
    a[i] = i;
  }
}