Gosu statements

A Gosu expression has a value, but Gosu statements do not. The result of a Gosu expression can be passed as an argument to a function. A Gosu statement does not have a result that can be passed as an argument to a function.

For example, the following lines are all Gosu expressions as each results in a value:

5 * 6
typeof 42
exists (var e in Claim.Exposures where e == null)

The following lines are all Gosu statements:

print(x * 3 + 5)
for (i in 10) { ... }
if (a == b) { ... }

Note: Do not confuse statement lists with expressions or Gosu blocks. Blocks are anonymous functions that Gosu can pass as objects, even as function arguments.

Statement lists

A statement list is a list containing zero or more Gosu statements enclosed by braces ({}).

The Gosu standard is always to omit semicolon characters at the ends of lines of Gosu code. Code is more readable without optional semicolons. In the rare cases in which you type multiple statement lists on one line, such as within block definitions, do use semicolons to separate statements.

Syntax

{ statement-list }

Multi-line example (no semicolons)

{
  var x = 0
  var y = myfunction( x )
 
  print( y )
}

Single-line example (semicolons)

var adder = \ x : int, y : int -> { print("I added!"); return x + y; }

Using the operator new as a statement

Use the new operator to instantiate an object. Although it is often used as an expression, new can also be a statement. For some types, this functionality may not be useful. However, if the constructor for the object triggers code that saves a copy of the new object, the return value from new may be unnecessary. Ignoring the return value and using new as a statement may permit more concise code in these cases.

For example, suppose that a constructor for a class that represents a book registers itself with a bookshelf object and saves the new object. Some code might merely create the book object and pass the bookshelf as a constructor argument:

new gw.example.Book( bookshelfReference, author, bookID )