Merge branch 'master' of ssh://animus.robocracy.org/srv/git/knowledge

1 files changed, 67 insertions, 0 deletions

diff --git a/software/ruby b/software/ruby
new file mode 100644
index 0000000..e64f73e
--- /dev/null
+++ b/software/ruby
@@ -0,0 +1,67 @@
+==================
+Ruby
+==================
+
+.. note:: This information is very rough, it's mostly my notes about what is 
+    different about Ruby syntax compared to similar modern interpreted 
+    pan-paradigm languages like Python.
+
+A unique intro to ruby is `"Why's Poignant Guide to Ruby"`__, a web-comic-y 
+short free online book by why the luck stiff. The more serious reference is 
+the "pickax" book.
+
+__ http://poignantguide.net/
+
+Blocks
+---------
+Blocks of code can be passed to functions, making ruby code more of a first
+order data type.
+
+Ranges 
+----------
+
+>>> 2..7                # => 2..7
+>>> (2..7).to_a         # => [2, 3, 4, 5, 6, 7]
+>>> (2...7).to_a        # => [2, 3, 4, 5, 6]
+>>> ('e'..'h').to_a     # => ["e", "f", "g", "h"]
+
+Control Structures
+--------------------
+Can use ``if`` after a statement::
+
+>>> a = c if c > b
+
+Along with the usual ``break`` and ``next``, there is ``redo`` which redoes
+the current loop (initial conditions may have been changed).
+
+
+Boolean Operators
+--------------------
+Anything that is not ``nill`` or ``false`` is true. To force interpretation
+as boolean, use ``!!`` (not not)::
+
+>>> !!(nil)     # => false
+>>> !!(true)    # => true 
+>>> !!('')      # => true 
+>>> !!(0)       # => true 
+>>> !!({})      # => true 
+
+
+Misc
+----------------
+Can use nasty Perl style regular expression stuff::
+
+>>> re1 = /\d+/
+>>> "There are 5 kilos of chunky bacon on the table!" =~ re1 # => 10, the index
+>>> $~ # =>         #<MatchData:0xb7c36754> 
+>>> $~.pre_hash     # => "There are "
+
+Also $1, $2, etc.
+
+The "splat operator", '*', either collects or expands extra arguments depending
+on syntax (I think this is kind of icky)::
+
+>>> a, b = 1, 2, 3, 4       # a=1, b=2
+>>> a, *b = 1, 2, 3, 4      # a=1, b=[2,3,4] 
+>>> c, d = 5, [6, 7, 8]     # c=5, d=[6,7,8]
+>>> c, d = 5, *[6, 7, 8]    # c=5, b=6