Functions

The control flow execution in Boson starts form the start function, which has to be defined in the .b file. The language currently the following features in functions:

• Function Call
• Function Arguments
• Return Value

Start

# This is a comment
# The execution starts here    
fn start() void {
    return; 
}

Declaring a function

# Defining a function
# Writing a return statement at the end of the function is mandatory 
fn m1() void {
    return;
}

# This is a comment
# The execution starts here    
fn start() void {
    return; 
}

Returning a value

# Defining a function
# Writing a return statement at the end of the function is mandatory 
fn m1() void {
    return;
}

# A function which returns a value of type int
fn m2() int {
    return 10;
}

# A function which returns a value of type double
fn m3() double {
    return 10.1;
}

# This is a comment
# The execution starts here    
fn start() void {
    int i = m2(); # i is initilized with 10
    double j = m3(); # j is initilized with 10.1
    return; 
}

Passing Arguments

fn getConstant() double {
    return 10.999;
}

fn doSomeProcessing(double v1,double v2) double {
    return v1 + v2; # Sum of the two variable
}

fn start() void {
    double j = doSomeProcessing(getConstant(),11.0);
    return; 
}

Recursion

consume fn printint(int i) void;


# Recursively computing fib number
fn fib(int n) int {
    if((n == 0) | (n == 1)) { return 1; }
    else { return fib(n - 1) + fib(n - 2); }
    return -1;
}

fn start() void {
    printint(fib(10));
    return; 
}

note

Look at the Structural Constructs section for more on conditionals