refactor to well-defined source input

build/src/source.rs

@@ -0,0 +1,44 @@
+//! Configuration of source binaries
+
+/// Target configiration of previous build step
+#[derive(Debug)]
+pub enum SourceTarget {
+	Emscripten,
+	Unknown,
+}
+
+/// Configuration of previous build step (cargo compilation)
+#[derive(Debug)]
+pub struct SourceInput<'a> {
+	target_dir: &'a str,
+	bin_name: &'a str,
+	target: SourceTarget,
+}
+
+impl<'a> SourceInput<'a> {
+	pub fn new<'b>(target_dir: &'b str, bin_name: &'b str) -> SourceInput<'b> {
+		SourceInput {
+			target_dir: target_dir,
+			bin_name: bin_name,
+			target: SourceTarget::Emscripten,
+		}
+	}
+
+	pub fn unknown(mut self) -> Self {
+		self.target = SourceTarget::Unknown;
+		self
+	}
+
+	pub fn emscripten(mut self) -> Self {
+		self.target = SourceTarget::Emscripten;
+		self
+	}
+
+	pub fn target_dir(&self) -> &str {
+		&self.target_dir
+	}
+
+	pub fn bin_name(&self) -> &str {
+		&self.bin_name
+	}
+}