Define polymorphic lenses and compile the runtime library

Makefile

@@ -0,0 +1,20 @@
+OCAMLC ?= ocamlc
+
+.PHONY: all test clean
+all: fieldglass.cma
+
+fieldglass.cmi: fieldglass.mli
+	$(OCAMLC) -c $<
+
+fieldglass.cmo: fieldglass.ml fieldglass.cmi
+	$(OCAMLC) -c $<
+
+fieldglass.cma: fieldglass.cmo
+	$(OCAMLC) -a $< -o $@
+
+test: all
+	$(OCAMLC) fieldglass.cma runtime.ml -o runtime.byte
+	./runtime.byte
+
+clean:
+	rm -f *.cmi *.cmo *.cma *.byte rewrite