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-rw-r--r--elixir.html.markdown18
1 files changed, 17 insertions, 1 deletions
diff --git a/elixir.html.markdown b/elixir.html.markdown
index 0a20e3df..720e080c 100644
--- a/elixir.html.markdown
+++ b/elixir.html.markdown
@@ -91,6 +91,11 @@ string.
<<1,2,3>> <> <<4,5>> #=> <<1,2,3,4,5>>
"hello " <> "world" #=> "hello world"
+# Ranges are represented as `start..end` (both inclusive)
+1..10 #=> 1..10
+lower..upper = 1..10 # Can use pattern matching on ranges as well
+[lower, upper] #=> [1, 10]
+
## ---------------------------
## -- Operators
## ---------------------------
@@ -190,7 +195,7 @@ cond do
"But I will"
end
-# It is common to see the last condition equal to `true`, which will always match.
+# It is common to set the last condition equal to `true`, which will always match.
cond do
1 + 1 == 3 ->
"I will never be seen"
@@ -338,6 +343,7 @@ rescue
RuntimeError -> "rescued a runtime error"
_error -> "this will rescue any error"
end
+#=> "rescued a runtime error"
# All exceptions have a message
try do
@@ -346,6 +352,7 @@ rescue
x in [RuntimeError] ->
x.message
end
+#=> "some error"
## ---------------------------
## -- Concurrency
@@ -364,6 +371,13 @@ spawn(f) #=> #PID<0.40.0>
# messages to the process. To do message passing we use the `send` operator.
# For all of this to be useful we need to be able to receive messages. This is
# achieved with the `receive` mechanism:
+
+# The `receive do` block is used to listen for messages and process
+# them when they are received. A `receive do` block will only
+# process one received message. In order to process multiple
+# messages, a function with a `receive do` block must recursively
+# call itself to get into the `receive do` block again.
+
defmodule Geometry do
def area_loop do
receive do
@@ -379,6 +393,8 @@ end
# Compile the module and create a process that evaluates `area_loop` in the shell
pid = spawn(fn -> Geometry.area_loop() end) #=> #PID<0.40.0>
+# Alternatively
+pid = spawn(Geometry, :area_loop, [])
# Send a message to `pid` that will match a pattern in the receive statement
send pid, {:rectangle, 2, 3}