OCaml compiler library : Ast_helper.Const

`sig
val mk :
?loc:Ast_helper.loc -> Parsetree.constant_desc -> Parsetree.constant
val char : ?loc:Ast_helper.loc -> char -> Parsetree.constant
val string :
?quotation_delimiter:string ->
?loc:Location.t -> string -> Parsetree.constant
val integer :
?loc:Ast_helper.loc -> ?suffix:char -> string -> Parsetree.constant
val int : ?loc:Ast_helper.loc -> ?suffix:char -> int -> Parsetree.constant
val int32 :
?loc:Ast_helper.loc -> ?suffix:char -> int32 -> Parsetree.constant
val int64 :
?loc:Ast_helper.loc -> ?suffix:char -> int64 -> Parsetree.constant
val nativeint :
?loc:Ast_helper.loc -> ?suffix:char -> nativeint -> Parsetree.constant
val float :
?loc:Ast_helper.loc -> ?suffix:char -> string -> Parsetree.constant
end`