Markup-language document formatting in memory-constrained environment

• US 20030221168A1
• Filed: 04/24/2003
• Published: 11/27/2003
• Est. Priority Date: 04/24/2002
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kozlov, Dmitri
• Granted Patent: US 7,313,758 B2
• Time in Patent Office: Days
• US Class Current: 715/513
• CPC Class Codes: G06F 40/143 Markup, e.g. Standard Generalized Markup Language [SGML] or Document Type Definition [DTD]

Abstract

Methods (600, 700, 900), apparatuses and computer program products are disclosed for parsing and formatting a document encoded using a markup language in a memory-constrained environment. The structure (100) of the document is represented by a tree having one or more nodes (n1-n10). One method (600) includes the steps of, for a current one of the nodes, freeing memory occupied by any previously formatted one of the nodes upon which formatting of the current node, according to a set of formatting rules, is independent; and building a partial document tree (500) using the current node and remaining previously formatted nodes upon which formatting of the current node, according to the set of formatting rules, is dependent. Another method includes the steps of obtaining information about one or more nodes of the document using a lookahead parser, and formatting the one or more nodes using the obtained information.

Claims

1. A method of parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said method including the steps of:

for a current one of said nodes, freeing memory occupied by any previously formatted one of said nodes upon which formatting of said current node, according to a set of formatting rules, is independent; and

building a partial document tree using the current node and remaining previously formatted nodes upon which formatting of said current node, according to said set of formatting rules, is dependent.

4. The method according to claim 1, further including the step of determining said one or more nodes affected by said set of formatting rules.

5. The method according to claim 4, wherein said determining step utilises one or more sequences of selectors, each sequence of selectors related to one of said formatting rules, applied to sibling nodes of said document tree.

6. The method according to claim 4, wherein said determining step includes the step of searching each formatting rule in said set of formatting rules for a current node.

7. The method according to claim 1, further including the steps of formatting said document using said partial document tree and outputting said formatted document.

2. A method of parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said method including the steps of:

obtaining information about one or more nodes of said document using a lookahead parser;

formatting said one or more nodes using said obtained information.

3. A method of parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said method including the steps of:

for a current one of said nodes, freeing memory occupied by any previously formatted one of said nodes upon which formatting of said current node, according to a set of formatting rules, is independent;

building a partial document tree using the current node and remaining previously formatted nodes upon which formatting of said current node, according to said set of formatting rules, is dependent;

obtaining information about one or more nodes of said partial document tree using a lookahead parser; and

formatting said one or more nodes using said obtained information.

8. An apparatus for parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said apparatus including;

means for, for a current one of said nodes, freeing memory occupied by any previously formatted one of said nodes upon which formatting of said current node, according to a set of formatting rules, is independent; and

means for building a partial document tree using the current node and remaining previously formatted nodes upon which formatting of said current node, according to said set of formatting rules, is dependent.

11. The apparatus according to claim 8, further including means for determining said one or more nodes affected by said set of formatting rules.

12. The apparatus according to claim 11, wherein said determining means utilises one or more sequences of selectors, each sequence of selectors related to one of said formatting rules, applied to sibling nodes of said document tree.

13. The apparatus according to claim 11, wherein said determining means includes means for searching each formatting rule in said set of formatting rules for a current node.

14. The apparatus according to claim 8, further including means for formatting said document using said partial document tree and outputting said formatted document.

9. An apparatus for parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said apparatus including:

means for obtaining information about one or more nodes of said document using a lookahead parser;

means for formatting said one or more nodes using said obtained information.

10. An apparatus for parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said apparatus including:

means for, for a current one of said nodes, freeing memory occupied by any previously formatted one of said nodes upon which formatting of said current node, according to a set of formatting rules, is independent;

means for building a partial document tree using the current node and remaining previously formatted nodes upon which formatting of said current node, according to said set of formatting rules, is dependent;

means for obtaining information about one or more nodes of said partial document tree using a lookahead parser; and

means for formatting said one or more nodes using said obtained information.

15. A computer program product having a computer readable medium having a computer program recorded therein for parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said computer program product including:

computer program code means for, for a current one of said nodes, freeing memory occupied by any previously formatted one of said nodes upon which formatting of said current node, according to a set of formatting rules, is independent; and

computer program code means for building a partial document tree using previously formatted nodes upon which formatting of said current node, according to said set of formatting rules, is dependent.

18. The computer program product according to claim 15, further including computer program code means for determining said one or more nodes affected by said set of formatting rules.

19. The computer program product according to claim 18, wherein said computer program code means for determining utilises one or more sequences of selectors, each sequence of selectors related to one of said formatting rules, applied to sibling nodes of said document tree.

20. The computer program product according to claim 18, wherein said computer program code means for determining includes computer program code means for searching each formatting rule in said set of formatting rules for a current node.

21. The computer program product according to claim 15, further including computer program code means for formatting sad document using said partial document tree and outputting said formatted document.

16. A computer program product having a computer readable medium having a computer program recorded therein for parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said computer program product including:

computer program code means for obtaining information about one or more nodes of said document using a lookahead parser;

computer program code means for formatting said one or more nodes using said obtained information.

17. A computer program product having a computer readable medium having a computer program recorded therein for parsing and formatting a document encoded using a markup language, the structure of said document represented by a tree having one or more nodes, said computer program product including:

computer program code means for, for a current one of said nodes, freeing memory occupied by any previously formatted one of said nodes upon which formatting of said current node, according to a set of formatting rules, is independent;

computer program code means for building a partial document tree using the current node and remaining previously formatted nodes upon which formatting of said current node, according to said set of formatting rules, is dependent;

computer program code means for obtaining information about one or more nodes of said partial document tree using a lookahead parser; and

computer program code means for formatting said one or more nodes using said obtained information.