matthewstokeley/pure-function-patterns.md

## pure-function-patterns.md

      
    Raw
  

              pure-function-patterns.md
            
          
/**
 * ht vue, lo
 * Cache a function
 */
function cached (
  fn: Function,
  resolver: Function
): Function {
   const cache = new WeakMap()
   return (function(str) {
     const key = resolver ? resolver(str) : str
     return cache.has(key) 
       ? cache.get(key)
       : cache.set(key, fn(str))
    })
}