on 12-Dec-2014 (Fri)

You can never make a default method that redefines one of the methods in the Object class. For example, you can’t define a default method for toString or equals, even though that might be attractive for interfaces such as List. As a consequence of the “classes win” rule, such a method could never win against Object.toString or Object.equals.

code to count words where length > 12 in traditional way:

int count = 0;
for (String w : words) {
  if (w.length() > 12) count++;
}

in Java 8 would look like this:

count = words.stream().filter(w -> w.length() > 12).count();

to parallelise search for words here:

count = words.stream().filter(w -> w.length() > 12).count();

you would change a method stream() to parallelStream()

In Java 8 you can turn any collection into a stream with the stream() from the Collection interface.

In Java 8 you can turn any array into a stream with the static Stream.of() method.

To generate infinite stream from a stateless function, you use Stream.generate()

Stream.iterate() generates an infinite stream from a "seed" (initial value) and then a function repeatedly applied to previous result.

The Collections.sort method sorts a collection in place, whereas Stream.sorted returns a new sorted stream.

The Optional.flatMap method works in the same way as Stream.flatMap if you consider an optional value to be a stream of size zero or one.

You can reassign vars

You can't reassign vals

the first element in a Scala array named steps is steps(0), not steps[0], as in Java

You cannot write “println 10”, but you can write “Console println 10”.

Accessing an element of an array in Scala is simply a method call like any other. This principle is not restricted to arrays: any application of an object to some arguments in parentheses will be transformed to an apply() method call. Of course this will compile only if that type of object actually defines an apply method.

When an assignment is made to a variable to which parentheses and one or more arguments have been applied, the compiler will transform that into an invocation of an update method that takes the arguments in parentheses as well as the object to the right of the equals sign.

Both mutable and immutable sets offer a + method, but their behavior differs. Whereas a mutable set will add the element to itself, an immutable set will create and return a new set with the element added.

Where you’d say “public” in Java, you simply say nothing in Scala. Public is Scala’s default access level.

method parameters in Scala is that they are vals, not vars

a semicolon is required if you write multiple statements on a single line

Quoted MVA spread involves a swap of notional equal to bond dirty price.

Quoted MVA spread involves a swap of notional equal to bond dirty price. Quoted spread, therefore, does not indicate unwind terms - your asset swap was likely bought at different dirty price than the one currently quoted, so you cannot easily unwind yours.

Spread: Spread applied to floating leg such that Swap PV = 100 – Bond DP

Spread: Spread applied to floating leg such that Swap FV = 100 – Bond DP

Trade: Bond bought for par, plus a swap.

MVA asset swap; trade: Bond bought for dirty price, plus a swap.

in par/par asset swap, swap notional is par (of the bond).

Swap notional is bond dirty price at settlement.

Fee of [Settlement DP] - 100 paid to ASW buyer at expiry.