typescript-functional-programming

A variety of functional programming examples in TypeScript.

See Index.ts for contents.

Functional Programming Fundamentals

• Map & Reduce
• Data Structures & recursion: Stack & Tree
• Lazy evaluation, Stream
• Monads

Promises

• A simplified implementation of JS Promises. [MyPromise.ts]
• A Promise.all implementation that uses advanced TS type inference. [MyPromiseAll.ts]

Parser Combinator & Math Evaluator

• A FP Parser Combinator where parser functions can be combined like regex. [ParserCombinator.ts]
• A tokenizer for math formulas using the Parser Combinator, to split "(123+45)*6" into "tokens" such as ["(", "123", "+", "45"...]. [Tokenizer.ts]
• A math formula evaluator that evaluates the tokens from the Tokenizer into a numeric result. e.g. "(123+45)*6" becomes the number 1008.[EvaluatorTests.ts]

TypeScript Language

• TS Basics: Arrays, objects, types, keyof, instanceof
• Method overloading with types
• Ways to infer types