From e8b9f47ce4102217d16707d80d31a663e683f716 Mon Sep 17 00:00:00 2001 From: Jason Yeo Date: Tue, 20 Oct 2015 22:26:37 +0800 Subject: Add a short tutorial for edn --- edn.html.markdown | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 edn.html.markdown (limited to 'edn.html.markdown') diff --git a/edn.html.markdown b/edn.html.markdown new file mode 100644 index 00000000..b8dc4e88 --- /dev/null +++ b/edn.html.markdown @@ -0,0 +1,107 @@ +--- +language: edn +filename: learnedn.edn +contributors: + - ["Jason Yeo", "https://github.com/jsyeo"] +--- + +Extensible Data Notation or EDN for short is a format for serializing data. + +The notation is used internally by Clojure to represent programs and +it is used commonly by Clojure and Clojurescript programs to transfer +data. Though there are implementations of EDN for many other +languages. + +The main benefit of EDN is that it is extensible, which we will see +how it is extended later on. + +```Clojure +; Comments start with a semicolon. +; Anythng after the semicolon is ignored. + +;;;;;;;;;;;;;;;;;;; +;;; Basic Types ;;; +;;;;;;;;;;;;;;;;;;; + +nil ; or aka null + +; Booleans +true +false + +; Strings are enclosed in double quotes +"hungarian breakfast" +"farmer's cheesy omelette" + +; Characters are preceeded by backslashes +\g \r \a \c \e + +; Keywords starts with a colon. They behave like enums. Kinda +; like symbols in ruby land. + +:eggs +:cheese +:olives + +; Symbols are used to represent identifiers. You can namespace symbols by +; using /. Whatever preceeds / is the namespace of the name. +#spoon +#kitchen/spoon ; not the same as #spoon +#kitchen/fork +#github/fork ; you can't eat with this + +; Integers and floats +42 +3.14159 + +; Lists are a sequence of values +(:bun :beef-patty 9 "yum!") + +; Vectors allow random access +[:gelato 1 2 -2] + +; Maps are associative data structures that associates the key with its value +{:eggs 2 + :lemon-juice 3.5 + :butter 1} + +; You're not restricted to using keywords as keys +{[1 2 3 4] "tell the people what she wore", + [5 6 7 8] "the more you see the more you hate"} + +; You may use commas for readability. They are treated as whitespaces. + +; Sets are collections that contain unique elements. +#{:a :b 88 "huat"} + +;;; Tagged Elements + +; EDN can be extended by tagging elements with # symbols. + +#MyYelpClone/MenuItem {:name "eggs-benedict" :rating 10} + +; 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 + +(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 + +(edn/read-string {:readers {'MyYelpClone/MenuItem map->menu-item}} + "#MyYelpClone/MenuItem {:name \"eggs-benedict\" :rating 10}") +; -> #user.MenuItem{:name "eggs-benedict", :rating 10} + +``` + +# References + +- [EDN spec](https://github.com/edn-format/edn) +- [Implementations](https://github.com/edn-format/edn/wiki/Implementations) +- [Tagged Elements](http://www.compoundtheory.com/clojure-edn-walkthrough/) -- cgit v1.2.3 From 5789ae677260840f8239d0054b051b06ef32d98c Mon Sep 17 00:00:00 2001 From: Jason Yeo Date: Tue, 20 Oct 2015 22:35:07 +0800 Subject: Reword the intro, make section more obvious --- edn.html.markdown | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'edn.html.markdown') diff --git a/edn.html.markdown b/edn.html.markdown index b8dc4e88..14bb25b4 100644 --- a/edn.html.markdown +++ b/edn.html.markdown @@ -7,13 +7,12 @@ contributors: Extensible Data Notation or EDN for short is a format for serializing data. -The notation is used internally by Clojure to represent programs and -it is used commonly by Clojure and Clojurescript programs to transfer -data. Though there are implementations of EDN for many other -languages. +The notation is used internally by Clojure to represent programs and it also +used as a data transfer format like JSON. Though it is more commonly used in +Clojure land, there are implementations of EDN for many other languages. -The main benefit of EDN is that it is extensible, which we will see -how it is extended later on. +The main benefit of EDN over JSON and YAML is that it is extensible, which we +will see how it is extended later on. ```Clojure ; Comments start with a semicolon. @@ -37,8 +36,7 @@ false \g \r \a \c \e ; Keywords starts with a colon. They behave like enums. Kinda -; like symbols in ruby land. - +; like symbols in ruby. :eggs :cheese :olives @@ -74,7 +72,9 @@ false ; Sets are collections that contain unique elements. #{:a :b 88 "huat"} -;;; Tagged Elements +;;;;;;;;;;;;;;;;;;;;;;; +;;; Tagged Elements ;;; +;;;;;;;;;;;;;;;;;;;;;;; ; EDN can be extended by tagging elements with # symbols. -- cgit v1.2.3 From 4ff79b2554ca3d16e4b64d0d4b367191cdc31887 Mon Sep 17 00:00:00 2001 From: Jason Yeo Date: Wed, 28 Oct 2015 17:46:57 +0800 Subject: Fix minor typographical errors --- edn.html.markdown | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'edn.html.markdown') diff --git a/edn.html.markdown b/edn.html.markdown index 14bb25b4..b303d63c 100644 --- a/edn.html.markdown +++ b/edn.html.markdown @@ -22,7 +22,7 @@ will see how it is extended later on. ;;; Basic Types ;;; ;;;;;;;;;;;;;;;;;;; -nil ; or aka null +nil ; also known in other languages as null ; Booleans true @@ -35,14 +35,15 @@ false ; Characters are preceeded by backslashes \g \r \a \c \e -; Keywords starts with a colon. They behave like enums. Kinda -; like symbols in ruby. +; Keywords start with a colon. They behave like enums. Kinda +; like symbols in Ruby. :eggs :cheese :olives -; Symbols are used to represent identifiers. You can namespace symbols by -; using /. Whatever preceeds / is the namespace of the name. +; Symbols are used to represent identifiers. They start with #. +; You can namespace symbols by using /. Whatever preceeds / is +; the namespace of the name. #spoon #kitchen/spoon ; not the same as #spoon #kitchen/fork @@ -52,7 +53,7 @@ false 42 3.14159 -; Lists are a sequence of values +; Lists are sequences of values (:bun :beef-patty 9 "yum!") ; Vectors allow random access -- cgit v1.2.3 From 5f6d0d030001c465656661632fbea540a54bae69 Mon Sep 17 00:00:00 2001 From: Jason Yeo Date: Wed, 28 Oct 2015 17:51:18 +0800 Subject: Kinda -> Kind of --- edn.html.markdown | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'edn.html.markdown') diff --git a/edn.html.markdown b/edn.html.markdown index b303d63c..655c20f1 100644 --- a/edn.html.markdown +++ b/edn.html.markdown @@ -35,7 +35,7 @@ false ; Characters are preceeded by backslashes \g \r \a \c \e -; Keywords start with a colon. They behave like enums. Kinda +; Keywords start with a colon. They behave like enums. Kind of ; like symbols in Ruby. :eggs :cheese -- cgit v1.2.3 From a72017573d893b9c0b17e7342dbe39630ba4a5d0 Mon Sep 17 00:00:00 2001 From: bureken Date: Sat, 31 Oct 2015 03:33:13 +0300 Subject: Typo fix --- edn.html.markdown | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'edn.html.markdown') diff --git a/edn.html.markdown b/edn.html.markdown index 655c20f1..0a0dc9b5 100644 --- a/edn.html.markdown +++ b/edn.html.markdown @@ -16,7 +16,7 @@ will see how it is extended later on. ```Clojure ; Comments start with a semicolon. -; Anythng after the semicolon is ignored. +; Anything after the semicolon is ignored. ;;;;;;;;;;;;;;;;;;; ;;; Basic Types ;;; -- cgit v1.2.3 From 38506983bb1d589734268b62bb87b4bad4601733 Mon Sep 17 00:00:00 2001 From: Willie Zhu Date: Sat, 31 Oct 2015 15:27:44 -0400 Subject: [edn/en] Fix grammar --- edn.html.markdown | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'edn.html.markdown') diff --git a/edn.html.markdown b/edn.html.markdown index 0a0dc9b5..d0bdddfc 100644 --- a/edn.html.markdown +++ b/edn.html.markdown @@ -5,13 +5,13 @@ contributors: - ["Jason Yeo", "https://github.com/jsyeo"] --- -Extensible Data Notation or EDN for short is a format for serializing data. +Extensible Data Notation (EDN) is a format for serializing data. -The notation is used internally by Clojure to represent programs and it also +The notation is used internally by Clojure to represent programs. It is also used as a data transfer format like JSON. Though it is more commonly used in -Clojure land, there are implementations of EDN for many other languages. +Clojure, there are implementations of EDN for many other languages. -The main benefit of EDN over JSON and YAML is that it is extensible, which we +The main benefit of EDN over JSON and YAML is that it is extensible. We will see how it is extended later on. ```Clojure @@ -59,7 +59,7 @@ false ; Vectors allow random access [:gelato 1 2 -2] -; Maps are associative data structures that associates the key with its value +; Maps are associative data structures that associate the key with its value {:eggs 2 :lemon-juice 3.5 :butter 1} @@ -68,7 +68,7 @@ false {[1 2 3 4] "tell the people what she wore", [5 6 7 8] "the more you see the more you hate"} -; You may use commas for readability. They are treated as whitespaces. +; You may use commas for readability. They are treated as whitespace. ; Sets are collections that contain unique elements. #{:a :b 88 "huat"} @@ -82,11 +82,11 @@ false #MyYelpClone/MenuItem {:name "eggs-benedict" :rating 10} ; 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]) -; To transform edn to clojure values, I will need to use the built in EDN +; To transform EDN to clojure values, I will need to use the built in EDN ; reader, edn/read-string (edn/read-string "{:eggs 2 :butter 1 :flour 5}") -- cgit v1.2.3 From f3b10beb01795bf7513ec8d06c9e90ab98df7a83 Mon Sep 17 00:00:00 2001 From: Adam Date: Fri, 12 Feb 2016 23:04:31 -0800 Subject: Clean up various errors --- edn.html.markdown | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'edn.html.markdown') diff --git a/edn.html.markdown b/edn.html.markdown index d0bdddfc..ca04df89 100644 --- a/edn.html.markdown +++ b/edn.html.markdown @@ -14,7 +14,7 @@ Clojure, there are implementations of EDN for many other languages. The main benefit of EDN over JSON and YAML is that it is extensible. We will see how it is extended later on. -```Clojure +```clojure ; Comments start with a semicolon. ; Anything after the semicolon is ignored. -- cgit v1.2.3