Expressions

^Syntax
Expression :
     LiteralExpression
     | ParensExpression
     | BlockExpression
     | OperatorExpression
     | FunctionExpression
     | StructExpression
     | ArrayExpression
     | TupleExpression
     | EnumExpression
     | UnitExpression
     | IndexExpression
     | FieldExpression
     | CallExpression
     | ConditionalExpression
     | LoopExpression
     | MatchExpression
     | PlaceholderExpression

Expressions are used to produce a value and trigger side effects.