Improve the "Tagged Elements" section of EDN doc

- Change Clojure code to eliminate errors and to match commented output
  > Change edn/read-string to clojure.edn/read-string (no _require_ in text)
  > Change map->menu-item to map->MenuItem to match defrecord and output
- Modify the text to make it easier to understand the given example
This commit is contained in:
Jonathan D Johnston 2017-10-21 20:33:14 -04:00
parent 65d4f596cd
commit d86597d499

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@ -84,22 +84,26 @@ github/fork ; you can't eat with this
#MyYelpClone/MenuItem {:name "eggs-benedict" :rating 10} #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. ; piece of EDN into a MenuItem record.
(defrecord MenuItem [name rating]) (defrecord MenuItem [name rating])
; To transform EDN to clojure values, I will need to use the built in EDN ; defrecord defined, among other things, map->MenuItem which will take a map
; reader, edn/read-string ; 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} ; -> {:eggs 2 :butter 1 :flour 5}
; To transform tagged elements, define the reader function and pass a map ; To transform tagged elements, pass to clojure.edn/read-string an option map
; that maps tags to reader functions to edn/read-string like so ; with a :readers map that maps tag symbols to data-reader functions, like so
(edn/read-string {:readers {'MyYelpClone/MenuItem map->menu-item}} (clojure.edn/read-string
"#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}") {:readers {'MyYelpClone/MenuItem map->MenuItem}}
"#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}")
; -> #user.MenuItem{:name "eggs-benedict", :rating 10} ; -> #user.MenuItem{:name "eggs-benedict", :rating 10}
``` ```