The Humble Hash
summary
Two implementations of Conway’s Game of Life show a concrete win: replacing recursive recomputation with a hash with default_proc caches generations and keeps the simulation interactive while the plain method version stalls; similar memoization turns a fib(35) from ~30 million calls into 69 cached lookups. A real bugfix at scale swaps an O(disclaimers × providers) scan (300 × 500 → 150,000 checks) for a set-backed provider lookup (≈800 checks). Also demos memoization hash cache and Ruby’s abbrev/set patterns.
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chapters (13)
- 0:00Introduction
- 5:13Basics
- 7:33Set
- 10:42Hash Example
- 14:34Default Values
- 24:46Abbrev Library
- 24:59Abbrev Library Overview
- 25:33Implementation
- 26:57Condensed Code
- 27:49Totals
- 29:37Memoization
- 30:52Summary
- 31:29Outro
