The manpage for bash v3.2.48 says: […] The format for arithmetic expansion is: $((expression)) The old format $[expression] is deprecated and will be removed in upcoming versions of bash. So $[…] is old syntax that should not be used anymore.
($!) is strict function application. That is, it evaluates the argument before evaluating the function. This is contrary to normal lazy function application in Haskell, e.g. f x or f $ x, which first start to evaluate the function f, and only compute the argument x if it is needed. For example succ (1 + … Read more
f = anotherdecorator(lambda x: x * 2)
You only need to specify semicolons in cases where it is ambiguous to the compiler what you are trying to do, and the absence of a semicolon would result in an obvious compiler error. The rule is: Don’t worry about this and don’t use semicolons at all (other than the two cases below). The compiler … Read more
There is no symbol for line continuation in Kotlin. As its grammar allows spaces between almost all symbols, you can just break the statement: val text = “This ” + “is ” + “a ” + “long ” + “long ” + “line” However, if the first line of the statement is a valid statement, … Read more
It’s a bitfield. It’s only valid in a struct definition, and it means that the system will only use 8 bits for your integer.
They are Bitwise Bit shift operators, they operate by shifting the number of bits being specified . Here is tutorial on how to use them. The signed left shift operator “<<” shifts a bit pattern to the left The signed right shift operator “>>” shifts a bit pattern to the right. The unsigned right shift … Read more
Consider this: Source DF: In [79]: df Out[79]: Brains Bodies 0 42 34 1 32 23 Selecting one column – results in Pandas.Series: In [80]: df[‘Brains’] Out[80]: 0 42 1 32 Name: Brains, dtype: int64 In [81]: type(df[‘Brains’]) Out[81]: pandas.core.series.Series Selecting subset of DataFrame – results in DataFrame: In [82]: df[[‘Brains’]] Out[82]: Brains 0 42 … Read more
=> is a new operator in C# 6 and indicates an Expression Bodied Function to use for that getter. Your two examples are synonymous as far as the compiler is concerned and merely return the value assigned. The => is syntactic sugar to make development a bit easier and require fewer lines of code to … Read more