Multi-Line Functions in Pine Script

Introduction to Multi-Line Functions

Pine Script™ supports multi-line functions for more complex operations that require multiple steps or calculations. These functions are defined over several lines, allowing for intricate logic and variable manipulations.

Syntax of Multi-Line Functions

The basic syntax for a multi-line function in Pine Script is:

<identifier>(<parameter_list>) =>
    <local_block>

<identifier>(<list of parameters>) =>
    <variable declaration>
    ...
    <variable declaration or expression>

Components of Multi-Line Functions

Parameter List: Defined similarly to single-line functions, with each parameter optionally having a default value.
Local Block: The body of the function consisting of multiple statements, each on a separate line.
Indentation: Each statement within the function body must be indented (using 4 spaces or 1 tab) to denote its inclusion in the function’s scope.
End of Function Body: The first unindented statement signals the end of the function’s body.

Example: Creating a Geometric Average Function

Consider the function geom_average which calculates the geometric average of two values:

geom_average(x, y) =>
    squareX = x * x
    squareY = y * y
    math.sqrt(squareX + squareY)

In this function:

squareX and squareY are local variables holding the squares of x and y, respectively.
The function math.sqrt computes the square root of the sum squareX + squareY.
The result of math.sqrt(squareX + squareY) is the output of the geom_average function.

Understanding the Function’s Flow

Variable Declaration: The variables squareX and squareY are declared and calculated within the function.
Final Calculation: The last statement of the function (math.sqrt(squareX + squareY)) is the result returned when the function is called.
Indentation: Note the importance of indentation for maintaining the function scope and clarity.

Conclusion and Key Takeaways

Multi-line functions in Pine Script allow for complex calculations and logical operations.
Proper indentation is crucial for defining the scope of the function’s body.
The last statement in the function determines the return value.