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In Elm is there a way to pattern match the arguments of a function to multiple definitions like in Haskell?
Example from Haskell:
factorial :: Int ->
factorial 0 = 1
factorial n = n * factorial (n - 1)
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Pattern matching allows you to match a value (or an object) against some patterns to select a branch of the code. From the C++ point of view, it may sound a bit similar to the switch statement. In functional languages, pattern matching can be used for matching on standard primitive values such as integers.
Pattern matching is the act of checking one or more inputs against a pre-defined pattern and seeing if they match. In Elm, there's only a fixed set of patterns we can match against, so pattern matching has limited application.
Patterns are written in JME syntax, but there are extra operators available to specify what does or doesn't match. The pattern-matching algorithm uses a variety of techniques to match different kinds of expression.
Pattern matching is the process of specifying a pattern to be searched for within a data set. The data set can be a file, a document, or a database. For example, a pattern match can be used to search for all occurrences of a word, phrase, or number within a document.
There is no equivalent of that syntax in Elm.
The easiest way to achieve similar behavior would be using pattern matching with case statement.
Please consider the following example:
factorial : Int -> Int
factorial n =
case n of
0 ->
1
_ ->
n * factorial (n - 1)
The _ from the example above serves as a wildcard to match any pattern, in this case, it's any integer different from 0
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