replay conditional compilation

Author: bobzhang

parsing/lexer.mli

@@ -19,6 +19,8 @@ val init : unit -> unit
 val token: Lexing.lexbuf -> Parser.token
 val skip_hash_bang: Lexing.lexbuf -> unit
 
+type directive_type 
+
 type error =
   | Illegal_character of char
   | Illegal_escape of string
@@ -28,6 +30,14 @@ type error =
   | Keyword_as_label of string
   | Invalid_literal of string
   | Invalid_directive of string * string option
+  | Unterminated_paren_in_conditional
+  | Unterminated_if
+  | Unterminated_else 
+  | Unexpected_token_in_conditional 
+  | Expect_hash_then_in_conditional
+  | Illegal_semver of string
+  | Unexpected_directive
+  | Conditional_expr_expected_type of directive_type * directive_type                           
 ;;
 
 exception Error of error * Location.t
@@ -61,3 +71,17 @@ val set_preprocessor :
   (unit -> unit) ->
   ((Lexing.lexbuf -> Parser.token) -> Lexing.lexbuf -> Parser.token) ->
   unit
+
+(** semantic version predicate *)
+val semver : Location.t ->   string -> string -> bool
+
+val filter_directive_from_lexbuf : Lexing.lexbuf -> (int * int) list
+
+val replace_directive_int : string -> int -> unit
+val replace_directive_string : string -> string -> unit
+val replace_directive_bool : string -> bool -> unit 
+val remove_directive_built_in_value : string -> unit
+
+(** @return false means failed to define *)
+val define_key_value : string -> string -> bool
+val list_variables : Format.formatter -> unit