Abstraction of types which support a binary addition
operator `x + y`

. For numeric types, this is
just familiar numeric addition. For `String`

, it is
string concatenation.

Integer next = current + 1; String helloWorld = "hello" + " " + "world";

A concrete class that implements this interface should be
a mathematical *semigroup*. That is, the addition
operation should be associative, satisfying:

`(x+y)+z == x+(y+z)`

A `Summable`

type might be a *monoid*, that is, a
semigroup with an additive identity element, usually
denoted `0`

, but this is not required. For example:

`String`

is a monoid with identity element`""`

,`Float`

is a monoid with identity element`0.0`

, and`Integer`

is a monoid with identity element`0`

.

For any monoid, the addition operation must satisfy:

`x + 0 == x`

By: Gavin

*no type hierarchy*

*no supertypes hierarchy*

Methods | |

`plus` | Source Code`shared formal Other plus(Other other)` The result of adding the given value to this value. This operation should never perform any kind of mutation upon either the receiving value or the argument value. For any two instances x + y |

Inherited Methods |

Methods inherited from: `Object` |