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more examples in README

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Nathan Marz 2015-05-11 19:36:52 -04:00
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README.md
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@ -25,6 +25,16 @@ user> (select [ALL :a even?]
`select` extracts a sequence of results from a data structure. It takes in a "selector", which is a sequence of steps on how to navigate into that data structure. In this case, `ALL` looks at every element in the sequence, `:a` looks at the :a key for each element currently navigated to, and `even?` filters out any elements that aren't an even value.
If you had a map with a sequence as the value for the :a key, here's how to get all odd numbers in that sequence:
```clojure
user> (use 'com.rpl.specter)
nil
user> (select [:a ALL odd?]
{:a [1 2 3 5] :b :c})
[1 3 5]
```
Another function called `update` is used to perform a transformation on a data structure. In addition to a selector, it takes in an "update function" which specifies what to do with each element navigated to. For example, here's how to increment all the even values for :a keys in a sequence of maps:
```clojure
@ -34,6 +44,17 @@ user> (update [ALL :a even?]
[{:a 1} {:a 3} {:a 5} {:a 3}]
```
Here's another example of update:
```clojure
user> (use 'com.rpl.specter)
nil
user> (update [:a ALL odd?]
dec
{:a [1 2 3 5] :b :c})
{:b :c, :a [0 2 2 4]}
```
Specter comes with all sorts of built-in ways of navigating data structures. For example, here's how to increment the last odd number in a sequence:
```clojure