Error handling for Asllib.
type error_desc = | BadField of string * AST.ty| MissingField of string list * AST.ty| BadSlices of error_handling_time * AST.slice list * int| TypeInferenceNeeded| UndefinedIdentifier of AST.identifier| MismatchedReturnValue of string| BadArity of AST.identifier * int * int| UnsupportedBinop of AST.binop * AST.literal * AST.literal| UnsupportedUnop of AST.unop * AST.literal| UnsupportedExpr of AST.expr| MismatchType of string * AST.type_desc list| NotYetImplemented of string| ConflictingTypes of AST.type_desc list * AST.ty| AssertionFailed of AST.expr| CannotParse| UnknownSymbol| NoCallCandidate of string * AST.ty list| TooManyCallCandidates of string * AST.ty list| BadTypesForBinop of AST.binop * AST.ty * AST.ty| CircularDeclarations of string| UnpureExpression of AST.expr| UnreconciliableTypes of AST.ty * AST.ty| AssignToImmutable of string| AlreadyDeclaredIdentifier of string| BadReturnStmt of AST.ty option| UnexpectedSideEffect of string| UncaughtException of string| OverlappingSlices of AST.slice list| BadLDI of AST.local_decl_item| BadRecursiveDecls of AST.identifier list| UnrespectedParserInvariant| ConstrainedIntegerExpected of AST.ty| ParameterWithoutDecl of AST.identifier| BaseValueEmptyType of AST.tytype error = error_desc AST.annotatedexception ASLException of errorval fatal : error -> 'aval fatal_from : 'a AST.annotated -> error_desc -> 'bval fatal_here : AST.position -> AST.position -> error_desc -> 'aval fatal_unknown_pos : error_desc -> 'aval error_handling_time_to_string : error_handling_time -> stringval pp_error : Format.formatter -> error_desc AST.annotated -> unitval error_to_string : error_desc AST.annotated -> stringval eprintln : error_desc AST.annotated -> unit