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What are type lambdas in Scala and what are their benefits?
..., another concrete type. Give List a String and it gives you List[String]. Etc.
So, List, Option can be considered to be type level functions of arity 1. Formally we say, they have a kind * -> *. The asterisk denotes a type.
Now Tuple2[_, _] is a type constructor with kind (*, *) -> * i.e. y...
Catching an exception while using a Python 'with' statement
... finally:
f.close()
Used as follows:
with opened_w_error("/etc/passwd", "a") as (f, err):
if err:
print "IOError:", err
else:
f.write("guido::0:0::/:/bin/sh\n")
share
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Android Fatal signal 11 (SIGSEGV) at 0x636f7d89 (code=1). How can it be tracked down?
... SIGSEGV + the lib .so name will go a lot farther than the useless code=1, etc... Next think about where your Java app could touch native code, even if it's nothing you're doing. I made the mistake of assuming it was a Service + UI threading issue where the Canvas was drawing something that was null...
Why should text files end with a newline?
...ning how critical it is to end files with an EOL. In C, C++, Java (JARs), etc... some standards will dictate a newline for validity - no such standard exists for JS, HTML, CSS.
For example, instead of using wc -l filename one could do awk '{x++}END{ print x}' filename , and rest assured that the t...
What is the meaning of “non temporal” memory accesses in x86
...
Non-Temporal SSE instructions (MOVNTI, MOVNTQ, etc.), don't follow the normal cache-coherency rules. Therefore non-temporal stores must be followed by an SFENCE instruction in order for their results to be seen by other processors in a timely fashion.
When data is produc...
How to create GUID / UUID?
...browsers, how "random" and seeded the built-in random number generator is, etc.
55 Answers
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Redis strings vs Redis hashes to represent JSON: efficiency?
...ws you to store more complicated Objects (with multiple layers of nesting, etc.) Option 3 is used when you really care about not polluting the main key namespace (i.e. you don't want there to be a lot of keys in your database and you don't care about things like TTL, key sharding, or whatever).
If...
Understanding slice notation
...','t','h']
>>> p[2:4] # Take two items off the front
['t','h']
# etc.
The first rule of slice assignment is that since slicing returns a list, slice assignment requires a list (or other iterable):
>>> p[2:3]
['t']
>>> p[2:3] = ['T']
>>> p
['P','y','T','h','o...
What's the difference between deadlock and livelock?
...eadlock: situation where nobody progress, doing nothing (sleeping, waiting etc..). CPU usage will be low;
Livelock: situation where nobody progress, but CPU is spent on the lock mechanism and not on your calculation;
Starvation: situation where one procress never gets the chance to run; by pure ba...
Javascript object Vs JSON
...t Literal notation is where the key contains a special character (if, :, - etc). It is worth noting that a key in JSON must be enclosed in double quotes.
If I convert the above object to JSON using var jSonString = JSON.stringify(testObject);, what is the difference between the 2 (JS obj and JSON...