How does Lazy Evaluation work in R?

Lazy evaluation in R refers to the process where function arguments are not evaluated until they are actually used within the function. This can improve performance by avoiding unnecessary computations, especially when dealing with large datasets or complex calculations.

# Example of lazy evaluation in R
lazy_function <- function(a, b) {
    print("Function called")
    a + 10  # Only 'a' is used, so 'b' is never evaluated
}

# Calling the function
result <- lazy_function(5, stop("This error is never triggered"))
print(result)

In this example, the second argument b contains an expression that would normally trigger an error, but because b is never used in the function, the error is never evaluated or raised. Lazy evaluation allows for more flexible and potentially more efficient function execution.