| # importing | |
| import sha # import the the sha module | |
| from animal import Animal # import the Animal class from animal.py | |
| # unit testing | |
| # http://docs.python.org/3/library/unittest.html | |
| import unittest | |
| class AnimalTest(unittest.TestCase): |
| type git # get the type of any command. Great for | |
| # seeing if a command exists. | |
| ls -t # sort by time, newest first | |
| ls -tr # sort by time, oldest first | |
| grep -r "test" FILE_OR_DIR # recursive full text search | |
| grep -i "test" FILE # case insensitive | |
| grep -c "pattern" FILE # count | |
| grep -n "pattern" # show line numbers |
Suppose you're writing a contract which involves a huge amount of participants. As an example, think of an online, blockchain-based Trading-Card Game with tournaments. How would you program a playCard function? You might be thinking of something like this:
function playCard(uint player, uint card){
...
else if (card == PROFESSOR_OAK){
// shuffles the player's hand on his deck
shuffleHand(player)
| it('should throw an error', cb => { | |
| const result = aMethodThatRejects() | |
| result.then(x => { cb('Expected error. Instead got ' + x) })) | |
| result.catch(() => cb()) | |
| }) |
Using WebSockets, React and Reflux together can be a beautiful thing, but the intial setup can be a bit of a pain. The below examples attempt to offer one (arguably enjoyable) way to use these tools together.
This trifect works well if you think of things like so:
this.state in react should instead live within stores. Stores can listen to other stores as well as to events being fired.
| # Automatically add completion for all aliases to commands having completion functions | |
| function alias_completion { | |
| local namespace="alias_completion" | |
| # parse function based completion definitions, where capture group 2 => function and 3 => trigger | |
| local compl_regex='complete( +[^ ]+)* -F ([^ ]+) ("[^"]+"|[^ ]+)' | |
| # parse alias definitions, where capture group 1 => trigger, 2 => command, 3 => command arguments | |
| local alias_regex="alias ([^=]+)='(\"[^\"]+\"|[^ ]+)(( +[^ ]+)*)'" | |
| # create array of function completion triggers, keeping multi-word triggers together |
| /* COMMAND LINE */ | |
| mongod & // start mongo server on port 27017 by default | |
| mongo mydb // launch mongo shell using the specified database | |
| // importing & exporting | |
| mongoimport -d mydb -c mycollection --jsonArray --file input.json | |
| mongoimport -d mydb -c mycollection --headerline --type csv --file input.csv | |
| mongoexport -d mydb -c mycollection --out output.json | |
| /* MONGO SHELL */ |
This gist shows how formal conditions of Solidity smart contracts can be automatically verified even in the presence of potential re-entrant calls from other contracts.
Solidity already supports formal verification of some contracts that do not make calls to other contracts. This of course excludes any contract that transfers Ether or tokens.
The Solidity contract below models a crude crowdfunding contract that can hold Ether and some person can withdraw Ether according to their shares. It is missing the actual access control, but the point that wants to be made
| @media all and (max-width: 1024px) {...} | |
| @media all and (min-width: 800px) and (max-width: 1024px) {...} | |
| @media not screen and (color) {...} | |
| @media only screen and (orientation: portrait) {...} | |
| @media all and (max-width: 420px) { | |
| section, aside { | |
| float: none; | |
| width: auto; | |
| } |
You can test with the iOS Simulator that comes with Xcode. Navigate to the Xcode app in the Finder, right click and select "Show Package Contents":
Then navigate to Contents > Applications, and open the shortcut to "iPhone Simulator" (it may be called "iOS Simulator" depending on which version of Xcode you're running):
