How deeply does Elixir in Action, Third Edition cover tail call?

Defines the final-operation condition, explains jump-based stack reuse, and applies it to recursive summation.

Tail call

As explained in Elixir in Action, Third Edition

A tail call is a function call that is the final operation performed by its caller, allowing the caller's execution frame to be reused.

A tail call is the final operation performed by a function. Elixir, through Erlang's execution model, can replace the caller's stack push with a jump, allowing the callee to reuse the caller's execution frame and consume no additional memory. section 3.4.2

Tail calls are especially useful for recursion. A function that calls itself at the end can continue through arbitrarily large iterations without accumulating stack frames. The usual pattern separates a public function from a private recursive helper carrying an accumulator. section 3.4.2

Tail-recursive list summation

ListHelper.sum/1 starts with an accumulator of zero, while do_sum/2 adds each head to the accumulated value and tail-calls itself with the remaining list. The empty-list clause returns the accumulated sum.

How Elixir in Action, Third Edition covers it

Cover of Elixir in Action, Third Edition

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Related concepts

tail-call optimizationused by · Tail-call optimization is a compiler or runtime transformation that executes an eligible call in tail position without allocating an additional call-stack frame.
callkind of · A function call is an operation or expression that invokes a function or other callable, optionally supplies arguments, and initiates its execution.

This explainer was generated by Manning's knowledge graph from the text of Elixir in Action, Third Edition. The section links point to the parts of the book it draws on.