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authorhyphz <drmoose94@gmail.com>2017-07-18 17:56:42 +0100
committerhyphz <drmoose94@gmail.com>2017-07-18 17:56:42 +0100
commit5ab5cb9800822d607be2c6ac943377811db98158 (patch)
tree3c804707822744c20da1de54ff60fc8c3197781b /elm.html.markdown
parent62102d02992f83b3a1fb745a39f36332dd4435b7 (diff)
parent6e7c5c793327f4a63b13e555894597915ca91fda (diff)
Merge remote-tracking branch 'adambard/master'
Diffstat (limited to 'elm.html.markdown')
-rw-r--r--elm.html.markdown28
1 files changed, 15 insertions, 13 deletions
diff --git a/elm.html.markdown b/elm.html.markdown
index 944ab770..99c23980 100644
--- a/elm.html.markdown
+++ b/elm.html.markdown
@@ -2,6 +2,7 @@
language: Elm
contributors:
- ["Max Goldstein", "http://maxgoldste.in/"]
+filename: learnelm.elm
---
Elm is a functional reactive programming language that compiles to (client-side)
@@ -50,18 +51,18 @@ not False -- True
["the", "quick", "brown", "fox"]
[1, 2, 3, 4, 5]
-- The second example can also be written with two dots.
-[1..5]
+List.range 1 5
-- Append lists just like strings.
-[1..5] ++ [6..10] == [1..10] -- True
+List.range 1 5 ++ List.range 6 10 == List.range 1 10 -- True
-- To add one item, use "cons".
-0 :: [1..5] -- [0, 1, 2, 3, 4, 5]
+0 :: List.range 1 5 -- [0, 1, 2, 3, 4, 5]
-- The head and tail of a list are returned as a Maybe. Instead of checking
-- every value to see if it's null, you deal with missing values explicitly.
-List.head [1..5] -- Just 1
-List.tail [1..5] -- Just [2, 3, 4, 5]
+List.head (List.range 1 5) -- Just 1
+List.tail (List.range 1 5) -- Just [2, 3, 4, 5]
List.head [] -- Nothing
-- List.functionName means the function lives in the List module.
@@ -85,7 +86,7 @@ snd ("elm", 42) -- 42
-- Access a field with a dot and the field name.
{ x = 3, y = 7 }.x -- 3
--- Or with an accessor fuction, which is a dot and the field name on its own.
+-- Or with an accessor function, which is a dot and the field name on its own.
.y { x = 3, y = 7 } -- 7
-- Update the fields of a record. (It must have the fields already.)
@@ -149,13 +150,14 @@ answer =
42
-- Pass functions as arguments to other functions.
-List.map double [1..4] -- [2, 4, 6, 8]
+List.map double (List.range 1 4) -- [2, 4, 6, 8]
-- Or write an anonymous function.
-List.map (\a -> a * 2) [1..4] -- [2, 4, 6, 8]
+List.map (\a -> a * 2) (List.range 1 4) -- [2, 4, 6, 8]
-- You can pattern match in function definitions when there's only one case.
-- This function takes one tuple rather than two arguments.
+-- This is the way you'll usually unpack/extract values from tuples.
area (width, height) =
width * height
@@ -178,7 +180,7 @@ fib n =
else
fib (n - 1) + fib (n - 2)
-List.map fib [0..8] -- [1, 1, 2, 3, 5, 8, 13, 21, 34]
+List.map fib (List.range 0 8) -- [1, 1, 2, 3, 5, 8, 13, 21, 34]
-- Another recursive function (use List.length in real code).
listLength aList =
@@ -309,7 +311,7 @@ import Graphics.Collage as C
-- An incoming port is just a type signature.
port clientID : Int
--- An outgoing port has a defintion.
+-- An outgoing port has a definition.
port clientOrders : List String
port clientOrders = ["Books", "Groceries", "Furniture"]
@@ -333,16 +335,16 @@ $ elm repl
-- Packages are identified by GitHub username and repo name.
-- Install a new package, and record it in elm-package.json.
-$ elm package install evancz/elm-html
+$ elm package install elm-lang/html
-- See what changed between versions of a package.
-$ elm package diff evancz/elm-html 3.0.0 4.0.2
+$ elm package diff elm-lang/html 1.1.0 2.0.0
-- Elm's package manager enforces semantic versioning, so minor version bumps
-- will never break your build!
```
The Elm language is surprisingly small. You can now look through almost any Elm
-source code and have a rough idea of what is going on. However, the possibilties
+source code and have a rough idea of what is going on. However, the possibilities
for error-resistant and easy-to-refactor code are endless!
Here are some useful resources.