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Module Yaxpo


module Yaxpo: sig .. end
Provides XML lexing and basic parsing through a "pull" interface. This is mostly just a lexer; see the Yaxpodom and Yaxposax modules for more conventional parsers.

Basic datatypes

exception Lex_error of string
thrown with a description when an error occurs during lexical analysis.
type txt = string
the type of literal character data
type cdata = string
the type of CDATA section data

type qname = {
   pfx : txt;
   local : txt;
}
the type of QNames (prefix:local). pfx = "" means no prefix.

type att = {
   att_name : qname;
   mutable att_value : txt;
}
the type of attributes

Serializers - useful for debugging

val string_of_qname : qname -> string
val string_of_att : att -> string

Pull Interface


type xml_token =
| Tok_text of txt
| Tok_cdata of cdata
| Tok_start_tag of qname * att list
| Tok_empty_ele of qname * att list
| Tok_end_tag of qname
| Tok_comment of txt
| Tok_pi of txt * txt
The type of XML tokens.
exception Parse_error of string * xml_token option
thrown with a description when an error occurs during lexical analysis. May also include the offending token if appropriate.

The distinction between a parse error and a lex error is not too well defined, so you should take it lightly.

val pull_next_token : #Cps_reader.t -> (xml_token -> unit) -> unit
Pulls the next token from the stream. The second argument is a continuation, which is a function you write. When pull_next_token completes, it invokes your continuation with the new token, instead of returning control. Depending on what reader you use, it is possible for pull_next_token to return control without having invoked your continuation; this may occur if there is not enough data available.

Important: pull_next_token only performs local lexical analysis on the next token in the stream. It maintains no call-to-call state and will not raise errors if tokens come in incorrect order, such as an unmatched end tag. Although it is not very difficult to do at all, this is the responsibility of higher-level parsers.
Raises