Call By Name vs Call By Need

Developers should learn call by name when working with languages that support lazy evaluation or need to delay computation until necessary, such as in Scala for implementing custom control structures or avoiding unnecessary evaluations meets developers should learn and use call by need when working in functional programming contexts, such as with languages like haskell, to manage infinite lists or streams without causing memory issues. Here's our take.

Call By Name

Nice Pick

Developers should learn call by name when working with languages that support lazy evaluation or need to delay computation until necessary, such as in Scala for implementing custom control structures or avoiding unnecessary evaluations

Pros

• It is useful in scenarios where arguments might be expensive to compute or have side effects that should only occur if the parameter is actually used, improving performance and enabling more expressive programming patterns like short-circuiting in logical operators
• Related to: scala, lambda-calculus

Cons

• Specific tradeoffs depend on your use case

Call By Need

Developers should learn and use call by need when working in functional programming contexts, such as with languages like Haskell, to manage infinite lists or streams without causing memory issues

Pros

• It is particularly useful for optimizing recursive algorithms and computations where arguments might be expensive to compute but are not always required, as it prevents unnecessary evaluations and reduces overhead
• Related to: functional-programming, haskell

Cons

• Specific tradeoffs depend on your use case

The Verdict

Use Call By Name if: You want it is useful in scenarios where arguments might be expensive to compute or have side effects that should only occur if the parameter is actually used, improving performance and enabling more expressive programming patterns like short-circuiting in logical operators and can live with specific tradeoffs depend on your use case.

Use Call By Need if: You prioritize it is particularly useful for optimizing recursive algorithms and computations where arguments might be expensive to compute but are not always required, as it prevents unnecessary evaluations and reduces overhead over what Call By Name offers.

The Bottom Line

Call By Name wins

Developers should learn call by name when working with languages that support lazy evaluation or need to delay computation until necessary, such as in Scala for implementing custom control structures or avoiding unnecessary evaluations