initial

src/parse.ml

@@ -0,0 +1,29 @@
+let parse stm g =
+  let s = (Token.new_scanner stm) in
+      try
+          Token.program s g
+      with End_of_file ->
+        Token.syntax_error s "program reached end of file before end keyword"
+
+let program s g =
+  if Token.match_token s Token.Begin then
+      let _ = generate_begin s g in
+      let _ = statements s g in
+      if Token.match_token s Token.End then
+      let _ = generate_end s g in ()
+      else Token.syntax_error s "program should end with end keyword"
+  else Token.syntax_error s "program should start with begin keyword"
+
+let rec statements s g = if statement s g then statements s g else ()
+
+let statement s g =
+  let t = next_token s in
+    if match t with
+      | Token.Read -> read s g
+      | Token.Write -> write s g
+      | Token.Identifier i -> assignment s g
+      | _ -> false
+    then
+        if Token.match_token s Token.Semicolon then true
+        else Token.syntax_error s "statement must end with semicolon"
+    else false