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Merge pull request #2935 from jdjohnston/edn-tags

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[edn/en] Improve the "Tagged Elements" section
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Andre Polykanine A.K.A. Menelion Elensúlë 2017-10-22 22:24:36 +03:00 committed by GitHub
commit d5308a8173
1 changed files with 12 additions and 8 deletions
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@ -84,22 +84,26 @@ github/fork ; you can't eat with this
#MyYelpClone/MenuItem {:name "eggs-benedict" :rating 10}
; Let me explain this with a clojure example. Suppose I want to transform that
; Let me explain this with a Clojure example. Suppose I want to transform that
; piece of EDN into a MenuItem record.
(defrecord MenuItem [name rating])
; To transform EDN to clojure values, I will need to use the built in EDN
; reader, edn/read-string
; defrecord defined, among other things, map->MenuItem which will take a map
; of field names (as keywords) to values and generate a user.MenuItem record
(edn/read-string "{:eggs 2 :butter 1 :flour 5}")
; To transform EDN to Clojure values, I will need to use the built-in EDN
; reader, clojure.edn/read-string
(clojure.edn/read-string "{:eggs 2 :butter 1 :flour 5}")
; -> {:eggs 2 :butter 1 :flour 5}
; To transform tagged elements, define the reader function and pass a map
; that maps tags to reader functions to edn/read-string like so
; To transform tagged elements, pass to clojure.edn/read-string an option map
; with a :readers map that maps tag symbols to data-reader functions, like so
(edn/read-string {:readers {'MyYelpClone/MenuItem map->menu-item}}
"#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}")
(clojure.edn/read-string
{:readers {'MyYelpClone/MenuItem map->MenuItem}}
"#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}")
; -> #user.MenuItem{:name "eggs-benedict", :rating 10}
```