April 20, 2014¶
Developed by Robbie Lynch
Supervised by Paul Barry
Institute of Technology, Carlow, Ireland.
Download¶
Download the IErlang Kernel for IPython at http://github.com/robbielynch/ierlang
Data Types¶
In [1]:
AnInt = 1234.
Out[1]:
1234
In [2]:
AFloat = 55 / 3.
Out[2]:
18.333333333333332
In [3]:
AString = "Awesome!".
Out[3]:
"Awesome!"
In [4]:
AnAtom = 'This is an atom with spaces'.
Out[4]:
'This is an atom with spaces'
In [5]:
atom_with_no_spaces.
Out[5]:
atom_with_no_spaces
In [6]:
{this, is, a, tuple_of_atoms}.
Out[6]:
{this,is,a,tuple_of_atoms}
In [7]:
AList = [1,2,3,4,5].
Out[7]:
[1,2,3,4,5]
Variable Bindings¶
i.e. Referring to previously assigned variables.
In [8]:
AVariable = 100.
Out[8]:
100
In [9]:
AnotherVar = 77.
Out[9]:
77
In [10]:
AVariable + AnotherVar.
Out[10]:
177
In [11]:
NedStark = [[]|[AnotherVar + AVariable]].
Out[11]:
[[],177]
In [12]:
NedStark.
Out[12]:
[[],177]
Built in Functions¶
In [13]:
lists:sort([10,9,8,3,5,4,6,1,7,2]).
Out[13]:
[1,2,3,4,5,6,7,8,9,10]
In [14]:
io:format("hello").
Out[14]:
ok
In [15]:
is_integer(4325345).
Out[15]:
true
In [16]:
os:cmd("pwd").
Out[16]:
"/home/robbie/dev/ierlang/src
"
In [17]:
is_binary(<<"Hello">>).
Out[17]:
true
Expressions¶
In [18]:
9283479238472398472398472394872398 * 28347632847623847623847623847623847623847632874623864.
Out[18]:
263164661000754185502995313263072243291280523500406936157710040110469708162166525705872
In [19]:
99 div 5. %%Integer division
Out[19]:
19
In [20]:
99 / 5.
Out[20]:
19.8
In [21]:
893475 - 98234798432579348753.
Out[21]:
-98234798432578455278
Errors¶
In [22]:
this will throw an error
Out[22]:
{badmatch,{error,{1,erl_parse,["syntax error before: ","will"]}}}
In [23]:
lists:flatten(notalist).
Out[23]:
function_clause
In [24]:
55 div 44.3.
Out[24]:
badarith
Terminal Commands¶
To make interacion with the terminal quicker and easier, you can run terminal commands
by pre-pending ;; before the command. For example:
In [25]:
;;pwd
Out[25]:
"/home/robbie/dev/ierlang/src
"
In [26]:
;;date
Out[26]:
"Sun Apr 20 16:56:04 BST 2014
"
In [27]:
;;whereis ipython
Out[27]:
"ipython: /usr/bin/ipython2.7 /usr/bin/X11/ipython2.7 /usr/local/bin/ipython /usr/share/man/man1/ipython.1.gz
"
In [28]:
;;ping -c 5 google.com
Out[28]:
"PING google.com (74.125.24.101) 56(84) bytes of data.
64 bytes from de-in-f101.1e100.net (74.125.24.101): icmp_req=1 ttl=44 time=60.0 ms
64 bytes from de-in-f101.1e100.net (74.125.24.101): icmp_req=2 ttl=44 time=68.5 ms
64 bytes from de-in-f101.1e100.net (74.125.24.101): icmp_req=3 ttl=44 time=47.4 ms
64 bytes from de-in-f101.1e100.net (74.125.24.101): icmp_req=4 ttl=44 time=67.1 ms
64 bytes from de-in-f101.1e100.net (74.125.24.101): icmp_req=5 ttl=44 time=45.8 ms
--- google.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4004ms
rtt min/avg/max/mdev = 45.816/57.810/68.506/9.563 ms
"
In [29]:
;;ls mochi*
Out[29]:
"mochijson2.beam
mochijson2.erl
mochinum.beam
mochinum.erl
"
We can even compile erlang via the terminal commands¶
In [30]:
;;erlc mochijson2.erl
Out[30]:
[]
It's possible to start the original IPython Notebook with the command
;;ipython notebook
Although, it does kill our kernel :(
Modules¶
We can create, save and compile erlang modules¶
And if we deliberatly leave an error on line 4... it will tell us....
In [31]:
-module(super_awesome_module). %%First line must begin with -module().
-export([my_favorite_numbers/0, unlucky_number/0]).
my_favorite_numbers()- %%<---------------------This is where the error is%%
[1, 2, 3, 4, 5].
unlucky_number()->
((278346287 * 98324928374) - (829437 * 3476) - (27368378729560724309 + (2 * 2))).
Out[31]:
super_awesome_module.erl:4: syntax error before: '-'
super_awesome_module.erl:2: function my_favorite_numbers/0 undefined
It also tells us when things work...
In [32]:
-module(super_awesome_module). %%First line must begin with -module().
-export([my_favorite_numbers/0, unlucky_number/0]).
my_favorite_numbers()->
[1, 2, 3, 4, 5].
unlucky_number()->
((278346287 * 98324928374) - (829437 * 3476) - (27368378729560724309 + (2 * 2))).
Out[32]:
Successfully Compiled
Now for the cool part¶
We can reference the exported functions from our compiled modules
In [33]:
super_awesome_module:my_favorite_numbers().
Out[33]:
[1,2,3,4,5]
In [34]:
lists:reverse(super_awesome_module:my_favorite_numbers()).
Out[34]:
[5,4,3,2,1]
In [35]:
super_awesome_module:unlucky_number().
Out[35]:
13
In [36]:
MyPid = spawn(super_awesome_module, unlucky_number, []).
Out[36]:
<0.49.0>
In [37]:
MyPid.
Out[37]:
<0.49.0>
- Encoding tuples inside other data structures
Encoding floats inside other data structuresERROR MESSAGES - They do not appear (Something to do with pyerr on ierlang side)- Cannot create notebooks outside ierlang/src directory
- Horrible installation and setup
- Having to edit the IPython code in order to parse erlang strings (lists of ints)
- Note that the editing of the IPython code does not affect the normal IPython in any way.
No Variable bindings (yet)Tuples are converted to lists when encoding- Project structure - it's a mess
- Not handling all of IPython's messages (yet)
Thanks for the help¶
- Paul Barry - Supervisor/Mastermind
- Andrew Gibiansky - IHaskell Creator
- Roberto Aloi - Erlang Sandbox Creator
Find me on Twitter¶
April 20, 2014 Developed by Robbie Lynch Supervised by Paul Barry Institute of Technology, Carlow, Ireland. Download Download the IErlang Kernel for IPython at http://github.com/robbielynch/ierlang