ava/expressions.md

Expressions

Expressions are the basis of programming in Ava. An expression is some code that will produce a value when evaluated.

Syntax

Most non-Definition code is considered an expression. Expressions include:

• Literals
• Variables
• Function Calls
• Control Expressions

In general, using a Literal or a Variable for an expression wraps that value in a pure function that returns the value when evaluated.

Control Expressions

If Then

The if/then expression expects an expression that returns a Boolean Value. That expression is evaluated. If it evaluates to true, the then expression is evaluated. Otherwise the else expression is evaluated.

if <boolean expr> then <expr> else <expr>

Do Yield

TODO: This is incomplete

The do/yield expression allows for imperative composition of monadic expressions.

do
    x <- foo()
    y <- bar()
    _ <- baz()
yield
    x + y