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_archive/rhai_engine/rhaibook/language/fn-curry.md

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+Function Pointer Currying
+=========================
+
+{{#include ../links.md}}
+
+It is possible to _curry_ a [function pointer] by providing partial (or all) arguments.
+
+Currying is done via the `curry` keyword and produces a new [function pointer] which carries
+the curried arguments.
+
+When the curried [function pointer] is called, the curried arguments are inserted starting from the _left_.
+
+The actual call arguments should be reduced by the number of curried arguments.
+
+```rust
+fn mul(x, y) {                  // function with two parameters
+    x * y
+}
+
+let func = mul;                 // <- de-sugars to 'Fn("mul")'
+
+func.call(21, 2) == 42;         // two arguments are required for 'mul'
+
+let curried = func.curry(21);   // currying produces a new function pointer which
+                                // carries 21 as the first argument
+
+let curried = curry(func, 21);  // function-call style also works
+
+curried.call(2) == 42;          // <- de-sugars to 'func.call(21, 2)'
+                                //    only one argument is now required
+```