add interface for to_elf

lib/vaporware/compiler/assemble.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module Vaporware
+  class Compiler::Assemble
+    attr_reader :input, :output
+    def self.compile!(input, output = File.basename(input, ".*")) = new(input, output).compile
+
+    def initialize(input, output = File.basename(input, ".*"))
+      @input, @output = input, output
+      @target_file = File.open(output, "wb")
+    end
+
+    def compile(compile_options = [])
+      self
+    end
+  end
+end

sig/vaporware.rbs

@@ -10,6 +10,19 @@ module Vaporware
     @generator: Vaporware::Compiler::Generator
     # instance methods
     def compile: (?compiler: String, ?compiler_options: Array[String]) -> nil
+
+    class Assemble
+      @input: String
+      @output: String
+      @target_file: File
+      # class methods
+      def self.compile!: (String, ?String) -> Vaporware::Compiler::Assemble
+      def initialize: (String, ?String) -> untyped
+
+      # instance methods
+      def compile: (?Array[String]) -> self
+    end
+
     class Generator
       REGISTER: Array[String]
       # instance variables