A Word About Tail Recursion

Take a look at the receive loop in the area server that we wrote earlier:

area_server_final.erl
​ 
loop() ->
​ 
​receive​
​ 
{From, {rectangle, Width, Ht}} ->
​ 
From ! {self(), Width * Ht},
​ 
loop();
​ 
{From, {circle, R}} ->
​ 
From ! {self(), 3.14159 * R * R},
​ 
loop();
​ 
{From, Other} ->
​ 
From ! {self(), {error,Other}},
​ 
loop()
​ 
​end​.

If you look carefully, you’ll see that every time we receive a message, we process the message and then immediately call loop() again. Such a procedure is called tail-recursive. A tail-recursive function can be compiled so that the last function call in a sequence of statements can be replaced by a simple jump to the start of the function being called. This means that a tail-recursive ...

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