OCaml: add step 0

.gitignore

@@ -28,6 +28,8 @@ go/step*
 go/mal
 java/target/
 java/dependency-reduced-pom.xml
+ocaml/*.cmi
+ocaml/*.swp
 rust/target/
 rust/mal
 rust/Cargo.lock

Makefile

@@ -11,7 +11,7 @@ PYTHON = python
 #
 
 IMPLS = bash c clojure coffee cs go haskell java js lua make mal \
-	perl php ps python r racket ruby rust scala vb
+	ocaml perl php ps python r racket ruby rust scala vb
 
 step0 = step0_repl
 step1 = step1_read_print
@@ -60,6 +60,7 @@ js_STEP_TO_PROG =      js/$($(1)).js
 lua_STEP_TO_PROG =     lua/$($(1)).lua
 make_STEP_TO_PROG =    make/$($(1)).mk
 mal_STEP_TO_PROG =     mal/$($(1)).mal
+ocaml_STEP_TO_PROG =   ocaml/$($(1)).ml
 perl_STEP_TO_PROG =    perl/$($(1)).pl
 php_STEP_TO_PROG =     php/$($(1)).php
 ps_STEP_TO_PROG =      ps/$($(1)).ps
@@ -84,6 +85,7 @@ js_RUNSTEP =      node ../$(2) $(3)
 lua_RUNSTEP =     ../$(2) $(3)
 make_RUNSTEP =    make -f ../$(2) $(3)
 mal_RUNSTEP =     $(call $(MAL_IMPL)_RUNSTEP,$(1),$(call $(MAL_IMPL)_STEP_TO_PROG,stepA),../$(2),")  #"
+ocaml_RUNSTEP =   ocaml ../$(2) $(3)
 perl_RUNSTEP =    perl ../$(2) --raw $(3)
 php_RUNSTEP =     php ../$(2) $(3)
 ps_RUNSTEP =      $(4)gs -q -I./ -dNODISPLAY -- ../$(2) $(3)$(4)

ocaml/step0_repl.ml

@@ -0,0 +1,23 @@
+(*
+  To try things at the ocaml repl:
+  rlwrap ocaml
+
+  To see type signatures of all functions:
+  ocamlc -i step0_repl.ml
+
+  To run the program:
+  ocaml step0_repl.ml
+*)
+
+let read str = str
+let eval ast any = ast
+let print exp = exp
+let rep str = print (eval (read str) "")
+
+let rec main =
+  try
+    while true do
+      print_string "user> ";
+      print_endline (rep (read_line ()));
+    done
+  with End_of_file -> ()