X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2FDEVEL%2Fpxp%2Fpxp%2Fdoc%2FREADME;fp=helm%2FDEVEL%2Fpxp%2Fpxp%2Fdoc%2FREADME;h=0000000000000000000000000000000000000000;hb=3ef089a4c58fbe429dd539af6215991ecbe11ee2;hp=b7ad5de592763e54b7279b5245d18a10aa289157;hpb=1c7fb836e2af4f2f3d18afd0396701f2094265ff;p=helm.git diff --git a/helm/DEVEL/pxp/pxp/doc/README b/helm/DEVEL/pxp/pxp/doc/README deleted file mode 100644 index b7ad5de59..000000000 --- a/helm/DEVEL/pxp/pxp/doc/README +++ /dev/null @@ -1,247 +0,0 @@ -****************************************************************************** -README - PXP, the XML parser for O'Caml -****************************************************************************** - - -============================================================================== -Abstract -============================================================================== - -PXP is a validating parser for XML-1.0 which has been written entirely in -Objective Caml. - -PXP is the new name of the parser formerly known as "Markup". PXP means -"Polymorphic XML parser" and emphasizes its most useful property: that the API -is polymorphic and can be configured such that different objects are used to -store different types of elements. - -============================================================================== -Download -============================================================================== - -You can download PXP as gzip'ed tarball [1]. The parser needs the Netstring [2] -package (0.9.3). Note that PXP requires O'Caml 3.00. - -============================================================================== -User's Manual -============================================================================== - -The manual is included in the distribution both as Postscript document and -bunch of HTML files. An online version can be found here [3]. - -============================================================================== -Author, Credits, Copying -============================================================================== - -PXP has been written by Gerd Stolpmann [4]; it contains contributions by -Claudio Sacerdoti Coen. You may copy it as you like, you may use it even for -commercial purposes as long as the license conditions are respected, see the -file LICENSE coming with the distribution. It allows almost everything. - -Thanks also to Alain Frisch and Haruo Hosoya for discussions and bug reports. - -============================================================================== -Description -============================================================================== - -PXP is a validating XML parser for O'Caml [5]. It strictly complies to the -XML-1.0 [6] standard. - -The parser is simple to call, usually only one statement (function call) is -sufficient to parse an XML document and to represent it as object tree. - -Once the document is parsed, it can be accessed using a class interface. The -interface allows arbitrary access including transformations. One of the -features of the document representation is its polymorphic nature; it is simple -to add custom methods to the document classes. Furthermore, the parser can be -configured such that different XML elements are represented by objects created -from different classes. This is a very powerful feature, because it simplifies -the structure of programs processing XML documents. - -Note that the class interface does not comply to the DOM standard. It was not a -development goal to realize a standard API (industrial developers can this much -better than I); however, the API is powerful enough to be considered as -equivalent with DOM. More important, the interface is compatible with the XML -information model required by many XML-related standards. - ------------------------------------------------------------------------------- -Detailed feature list ------------------------------------------------------------------------------- - -- The XML instance is validated against the DTD; any violation of a validation - constraint leads to the rejection of the instance. The validator has been - carefully implemented, and conforms strictly to the standard. If needed, it - is also possible to run the parser in a well-formedness mode. - -- If possible, the validator applies a deterministic finite automaton to - validate the content models. This ensures that validation can always be - performed in linear time. However, in the case that the content models are - not deterministic, the parser uses a backtracking algorithm which can be - much slower. - It is also possible to reject non-deterministic content - models. - -- In particular, the validator also checks the complicated rules whether - parentheses are properly nested with respect to entities, and whether the - standalone declaration is satisfied. On demand, it is checked whether the - IDREF attributes only refer to existing nodes. - -- Entity references are automatically resolved while the XML text is being - scanned. It is not possible to recognize in the object tree where a - referenced entity begins or ends; the object tree only represents the - logical structure. - -- External entities are loaded using a configurable resolver infrastructure. - It is possible to connect the parser with an arbitrary XML source. - -- The parser can read XML text encoded in a variety of character sets. - Independent of this, it is possible to choose the encoding of the internal - representation of the tree nodes; the parser automatically converts the - input text to this encoding. Currently, the parser supports UTF-8 and - ISO-8859-1 as internal encodings. - -- The interface of the parser has been designed such that it is best - integrated into the language O'Caml. The first goal was simplicity of usage - which is achieved by many convenience methods and functions, and by allowing - the user to select which parts of the XML text are actually represented in - the tree. For example, it is possible to store processing instructions as - tree nodes, but the parser can also be configured such that these - instructions are put into hashtables. The information model is compatible - with the requirements of XML-related standards such as XPath. - -- In particular, the node tree can optionally contain or leave out processing - instructions and comments. It is also possible to generate a "super root" - object which is the parent of the root element. The attributes of elements - are normally not stored as nodes, but it is possible to get them wrapped - into nodes. - -- There is also an interface for DTDs; you can parse and access sequences of - declarations. The declarations are fully represented as recursive O'Caml - values. - ------------------------------------------------------------------------------- -Code examples ------------------------------------------------------------------------------- - -This distribution contains several examples: - -- validate: simply parses a document and prints all error messages - -- readme: Defines a DTD for simple "README"-like documents, and offers - conversion to HTML and text files [7]. - -- xmlforms: This is already a sophisticated application that uses XML as style - sheet language and data storage format. It shows how a Tk user interface can - be configured by an XML style, and how data records can be stored using XML. - ------------------------------------------------------------------------------- -Restrictions and missing features ------------------------------------------------------------------------------- - -The following restrictions apply that are not violations of the standard: - -- The attributes "xml:space", and "xml:lang" are not supported specially. (The - application can do this.) - -- The built-in support for SYSTEM and PUBLIC identifiers is limited to local - file access. There is no support for catalogs. The parser offers a hook to - add missing features. - -- It is currently not possible to check for interoperatibility with SGML. - -The following features are also missing: - -- There is no special support for namespaces. (Perhaps in the next release?) - -- There is no support for XPATH or XSLT. - -However, I hope that these features will be implemented soon, either by myself -or by contributors (who are invited to do so). - ------------------------------------------------------------------------------- -Recent Changes ------------------------------------------------------------------------------- - -- Changed in 1.0: - Support for document order. - -- Changed in 0.99.8: - Several fixes of bugs reported by Haruo Hosoya and Alain Frisch. - The class type "node" has been extended: you can go directly to the next and - previous nodes in the list; you can refer to nodes by position. - There are now some iterators for nodes: find, find_all, find_element, - find_all_elements, map_tree, iter_tree. - Experimental support for viewing attributes as nodes; I hope that helps - Alain writing his XPath evaluator. - The user's manual has been revised and is almost up to date. - -- Changed in 0.99.7: - There are now additional node types T_super_root, T_pinstr and T_comment, - and the parser is able to create the corresponding nodes. - The functions for character set conversion have been moved to the Netstring - package; they are not specific for XML. - -- Changed in 0.99.6: - Implemented a check on deterministic content models. Added an alternate - validator basing on a DFA. - This means that now all mandatory features for - an XML-1.0 parser are implemented! The parser is now substantially complete. - -- Changed in 0.99.5: - The handling of ID and IDREF attributes has changed. The index of nodes - containing an ID attribute is now separated from the document. Optionally - the parser now checks whether the IDREF attributes refer to existing - elements. - The element nodes can optionally store the location in the source XML code. - The method 'write' writes the XML tree in every supported encoding. - (Successor of 'write_compact_as_latin1'.) - Several smaller changes and fixes. - -- Changed in 0.99.4: - The module Pxp_reader has been modernized. The resolver classes are simpler - to use. There is now support for URLs. - The interface of Pxp_yacc has been improved: The type 'source' is now - simpler. The type 'domspec' has gone; the new 'spec' is opaque and performs - better. There are some new parsing modes. - Many smaller changes. - -- Changed in 0.99.3: - The markup_* modules have been renamed to pxp_*. There is a new - compatibility API that tries to be compatible with markup-0.2.10. - The type "encoding" is now a polymorphic variant. - -- Changed in 0.99.2: - Added checks for the constraints about the standalone declaration. - Added regression tests about attribute normalization, attribute checks, - standalone checks. - Fixed some minor errors of the attribute normalization function. - The bytecode/native archives are now separated in a general part, in a - ISO-8859-1-relevant part, and a UTF-8-relevant part. The parser can again be - compiled with ocamlopt. - -- Changed in 0.99.1: - In general, this release is an early pre-release of the next stable version - 1.00. I do not recommend to use it for serious work; it is still very - experimental! - The core of the parser has been rewritten using a self-written parser - generator. - The lexer has been restructured, and can now handle UTF-8 encoded files. - Numerous other changes. - - --------------------------- - -[1] see http://www.ocaml-programming.de/packages/pxp-1.0.tar.gz - -[2] see http://www.ocaml-programming.de/packages/documentation/netstring - -[3] see http://www.ocaml-programming.de/packages/documentation/pxp/manual - -[4] see mailto:gerd@gerd-stolpmann.de - -[5] see http://caml.inria.fr/ - -[6] see http://www.w3.org/TR/1998/REC-xml-19980210.html - -[7] This particular document is an example of this DTD! - - -