‘Higher-order functions’ is a fancy term for functions that take other functions as arguments or that return functions. Very powerful!

Based on my understanding of FHIRPath - functions like toString() should not return a collection, they should return a string, toDecimal a decimal, etc. In playing with demo and looking at the code - ...

One of the confusing aspects of JavaScript is that any function may or may not return a value at any point in time. When a function exits without any return statement executing, the function returns ...