Method add_variable

package/svelte/compiler.js:14477–14482

(id2, init)

      this.has_animation = true;
    }
    add_variable(id2, init) {
      if (this.variables.has(id2.name)) {
        throw new Error(`Variable '${id2.name}' already initialised with a different value`);
      }
      this.variables.set(id2.name, { id: id2, init });
    }
    alias(name) {
      if (!this.aliases.has(name)) {
        this.aliases.set(name, this.get_unique_name(name));