'->' to '=>'

Author: psychometrician

Diff for: callbacks.tex

@@ -342,7 +342,7 @@ \section{Functional Programming}\label{s:callbacks-functional}
 \begin{minted}{js}
 const test = [1,2,3]
 
-const pure = (values) -> {
+const pure = (values) => {
   result = []
   for (let v of values) {
     result.push(v + 1)