constexpr.js

macro constexpr {
  rule { ($e:expr) } => {
    (function() {
      macro cexpr {
        case { _ } => {
          return [makeValue($e, #{ here })];
        }
      }
      return cexpr;
    }())
  }
}

// Unfortunately requires an IIFE to appease the parser. Needs
// localexpand if we want to get rid of it.
// var a = 1 + constexpr(1 + 2);

update -- this works now

macro constexpr {
    case {_($e:expr) } => {
        return localExpand(#{
            macro cexpr {
                case { _ } => {
                    return [makeValue($e, #{ here })];
                }
            }
            cexpr
        });
    }
}

// compiles to `var a = 1 + 3;`
var a = 1 + constexpr(1 + 2);