IfExpr

Syntax

elif_expr = { "elif" ~ expr ~ "{" ~ expr ~ "}" }
if_expr = { "if" ~ expr ~ "{" ~ expr ~ "}" ~ (elif_expr)* ~ "else" ~ "{" ~ expr ~ "}" }

Proto

/** A message representing an else-if */
message Elif {
    required Expr condition = 1; // The condition to call if
    required Expr then = 2; // The expression to call
}

/** A message representing an if expression */
message IfExpr {
    required Expr condition = 1; // The condition to call if
    required Expr then = 2; // The expression to call
    repeated Elif elif = 3; // The else-if conditions
    required Expr else = 4; // The else condition
}

Runtime Semantics: Evaluation

• Let conditionResult be condition evaluated with Local Scope and Module Scope
• If conditionResult is true
  • Return then evaluated with Local Scope and Module Scope
• Else
  • For each elif, let conditionResult be condition evaluated with Local Scope and Module Scope
    • If conditionResult is true
      • Return then evaluated with Local Scope and Module Scope
  • Return else evaluated with Local Scope and Module Scope