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Diffstat (limited to 'src/content/chapter1_functions/lesson02_tail_calls')
-rw-r--r-- | src/content/chapter1_functions/lesson02_tail_calls/code.gleam | 21 | ||||
-rw-r--r-- | src/content/chapter1_functions/lesson02_tail_calls/text.html | 23 |
2 files changed, 0 insertions, 44 deletions
diff --git a/src/content/chapter1_functions/lesson02_tail_calls/code.gleam b/src/content/chapter1_functions/lesson02_tail_calls/code.gleam deleted file mode 100644 index d823eec..0000000 --- a/src/content/chapter1_functions/lesson02_tail_calls/code.gleam +++ /dev/null @@ -1,21 +0,0 @@ -import gleam/io - -pub fn main() { - io.debug(factorial(5)) - io.debug(factorial(7)) -} - -pub fn factorial(x: Int) -> Int { - // The public function calls the private tail recursive function - factorial_loop(x, 1) -} - -fn factorial_loop(x: Int, accumulator: Int) -> Int { - case x { - 1 -> accumulator - - // The last thing this function does is call itself - // In the previous lesson the last thing it did was multiple two ints - _ -> factorial_loop(x - 1, accumulator * x) - } -} diff --git a/src/content/chapter1_functions/lesson02_tail_calls/text.html b/src/content/chapter1_functions/lesson02_tail_calls/text.html deleted file mode 100644 index ec39cda..0000000 --- a/src/content/chapter1_functions/lesson02_tail_calls/text.html +++ /dev/null @@ -1,23 +0,0 @@ -<p> - When a function is called a new stack frame is created in memory to store the - arguments and local variables of the function. If lots of these frames are - created during recursion then the program would use a large amount of memory, - or even crash the program if some limit is hit. -</p> -<p> - To avoid this problem Gleam supports <em>tail call optimisation</em>, which - allows the compiler to reuse the stack frame for the current function if a - function call is the last thing the function does, removing the memory cost. -</p> - -<p> - Unoptimised recursive functions can often be rewritten into tail call - optimised functions by using an accumulator. An accumulator is a variable that - is passed along in addition to the data, similar to a mutable variable in a - language with <code>while</code> loops. -</p> -<p> - Accumulators should be hidden away from the users of your code, they are - internal implementation details. To do this write a public function that calls - a recursive private function with the initial accumulator value. -</p> |