02-01 Defining a Function by Pattern Matching (Introduction to Haskell) скачать в хорошем качестве

02-01 Defining a Function by Pattern Matching (Introduction to Haskell)

We explain how to systematically define function by means of pattern matching, in a step-by-step process. We also introduce the concept of typed holes that help during the incremental development process. Course page with self-test questions: https://teaching.well-typed.com/intro... 00:00 Defining a function systematically 00:37 Setting up an empty module and GHCi 01:04 Compiler pragmas, enabling all warnings 01:49 Hiding functions from the Prelude 03:21 Type signature 05:28 A binding with a placeholder 06:10 undefined 07:07 Typed holes 10:08 Introducing names for the arguments 13:33 "One-liners" versus pattern matching 16:19 Systematic pattern matching 17:19 Splitting into multiple cases 18:56 Solving the case for the empty list 19:17 Recursion and solving the "cons" case 22:35 Improving the definition, fixing warnings 23:09 Wildcard patterns 24:23 Names that start with underscores 25:47 Trying out the function in GHCi 26:11 Discussing the quality of the definition 26:42 Recap: the "standard design pattern" (on lists) 27:15 Optionally aligning equations 27:52 Terminology: modules, declarations