pattern.c.svn-base

这是一个用于解析xml文件的类库。使用这个类库

			return(0);
		    if (!xmlStrEqual(step->value, node->ns->href))
			return(0);
		}
		break;
            case XML_OP_ALL:
		if (node->type != XML_ELEMENT_NODE)
		    return(0);
		break;
	}
    }
    return(1);
}

/************************************************************************
 *									*
 *			Dedicated parser for templates			*
 *									*
 ************************************************************************/

#define TODO 								\
    xmlGenericError(xmlGenericErrorContext,				\
	    "Unimplemented block at %s:%d\n",				\
            __FILE__, __LINE__);
#define CUR (*ctxt->cur)
#define SKIP(val) ctxt->cur += (val)
#define NXT(val) ctxt->cur[(val)]
#define CUR_PTR ctxt->cur

#define SKIP_BLANKS 							\
    while (IS_BLANK_CH(CUR)) NEXT

#define CURRENT (*ctxt->cur)
#define NEXT ((*ctxt->cur) ?  ctxt->cur++: ctxt->cur)


#define PUSH(op, val, val2) 						\
    if (xmlPatternAdd(ctxt, ctxt->comp, (op), (val), (val2))) goto error;

#define XSLT_ERROR(X)							\
    { xsltError(ctxt, __FILE__, __LINE__, X);			\
      ctxt->error = (X); return; }

#define XSLT_ERROR0(X)							\
    { xsltError(ctxt, __FILE__, __LINE__, X);			\
      ctxt->error = (X); return(0); }

#if 0
/**
 * xmlPatScanLiteral:
 * @ctxt:  the XPath Parser context
 *
 * Parse an XPath Litteral:
 *
 * [29] Literal ::= '"' [^"]* '"'
 *                | "'" [^']* "'"
 *
 * Returns the Literal parsed or NULL
 */

static xmlChar *
xmlPatScanLiteral(xmlPatParserContextPtr ctxt) {
    const xmlChar *q, *cur;
    xmlChar *ret = NULL;
    int val, len;

    SKIP_BLANKS;
    if (CUR == '"') {
        NEXT;
	cur = q = CUR_PTR;
	val = xmlStringCurrentChar(NULL, cur, &len);
	while ((IS_CHAR(val)) && (val != '"')) {
	    cur += len;
	    val = xmlStringCurrentChar(NULL, cur, &len);
	}
	if (!IS_CHAR(val)) {
	    ctxt->error = 1;
	    return(NULL);
	} else {
	    ret = xmlStrndup(q, cur - q);
        }
	cur += len;
	CUR_PTR = cur;
    } else if (CUR == '\'') {
        NEXT;
	cur = q = CUR_PTR;
	val = xmlStringCurrentChar(NULL, cur, &len);
	while ((IS_CHAR(val)) && (val != '\'')) {
	    cur += len;
	    val = xmlStringCurrentChar(NULL, cur, &len);
	}
	if (!IS_CHAR(val)) {
	    ctxt->error = 1;
	    return(NULL);
	} else {
	    ret = xmlStrndup(q, cur - q);
        }
	cur += len;
	CUR_PTR = cur;
    } else {
	/* XP_ERROR(XPATH_START_LITERAL_ERROR); */
	ctxt->error = 1;
	return(NULL);
    }
    return(ret);
}
#endif

/**
 * xmlPatScanName:
 * @ctxt:  the XPath Parser context
 *
 * [4] NameChar ::= Letter | Digit | '.' | '-' | '_' | 
 *                  CombiningChar | Extender
 *
 * [5] Name ::= (Letter | '_' | ':') (NameChar)*
 *
 * [6] Names ::= Name (S Name)*
 *
 * Returns the Name parsed or NULL
 */

static xmlChar *
xmlPatScanName(xmlPatParserContextPtr ctxt) {
    const xmlChar *q, *cur;
    xmlChar *ret = NULL;
    int val, len;

    SKIP_BLANKS;

    cur = q = CUR_PTR;
    val = xmlStringCurrentChar(NULL, cur, &len);
    if (!IS_LETTER(val) && (val != '_') && (val != ':'))
	return(NULL);

    while ((IS_LETTER(val)) || (IS_DIGIT(val)) ||
           (val == '.') || (val == '-') ||
	   (val == '_') || 
	   (IS_COMBINING(val)) ||
	   (IS_EXTENDER(val))) {
	cur += len;
	val = xmlStringCurrentChar(NULL, cur, &len);
    }
    ret = xmlStrndup(q, cur - q);
    CUR_PTR = cur;
    return(ret);
}

/**
 * xmlPatScanNCName:
 * @ctxt:  the XPath Parser context
 *
 * Parses a non qualified name
 *
 * Returns the Name parsed or NULL
 */

static xmlChar *
xmlPatScanNCName(xmlPatParserContextPtr ctxt) {
    const xmlChar *q, *cur;
    xmlChar *ret = NULL;
    int val, len;

    SKIP_BLANKS;

    cur = q = CUR_PTR;
    val = xmlStringCurrentChar(NULL, cur, &len);
    if (!IS_LETTER(val) && (val != '_'))
	return(NULL);

    while ((IS_LETTER(val)) || (IS_DIGIT(val)) ||
           (val == '.') || (val == '-') ||
	   (val == '_') ||
	   (IS_COMBINING(val)) ||
	   (IS_EXTENDER(val))) {
	cur += len;
	val = xmlStringCurrentChar(NULL, cur, &len);
    }
    ret = xmlStrndup(q, cur - q);
    CUR_PTR = cur;
    return(ret);
}

#if 0
/**
 * xmlPatScanQName:
 * @ctxt:  the XPath Parser context
 * @prefix:  the place to store the prefix
 *
 * Parse a qualified name
 *
 * Returns the Name parsed or NULL
 */

static xmlChar *
xmlPatScanQName(xmlPatParserContextPtr ctxt, xmlChar **prefix) {
    xmlChar *ret = NULL;

    *prefix = NULL;
    ret = xmlPatScanNCName(ctxt);
    if (CUR == ':') {
        *prefix = ret;
	NEXT;
	ret = xmlPatScanNCName(ctxt);
    }
    return(ret);
}
#endif

/**
 * xmlCompileStepPattern:
 * @ctxt:  the compilation context
 *
 * Compile the Step Pattern and generates a precompiled
 * form suitable for fast matching.
 *
 * [3]    Step    ::=    '.' | NameTest
 * [4]    NameTest    ::=    QName | '*' | NCName ':' '*' 
 */

static void
xmlCompileStepPattern(xmlPatParserContextPtr ctxt) {
    xmlChar *token = NULL;
    xmlChar *name = NULL;
    const xmlChar *URI = NULL;
    xmlChar *URL = NULL;

    SKIP_BLANKS;
    if (CUR == '.') {
	NEXT;
	PUSH(XML_OP_ELEM, NULL, NULL);
	return;
    }
    name = xmlPatScanNCName(ctxt);
    if (name == NULL) {
	if (CUR == '*') {
	    NEXT;
	    PUSH(XML_OP_ALL, NULL, NULL);
	    return;
	} else {
	    ERROR(NULL, NULL, NULL,
		    "xmlCompileStepPattern : Name expected\n");
	    ctxt->error = 1;
	    return;
	}
    }
    SKIP_BLANKS;
    if (CUR == ':') {
	NEXT;
	if (CUR != ':') {
	    xmlChar *prefix = name;
	    xmlNsPtr ns;

	    /*
	     * This is a namespace match
	     */
	    token = xmlPatScanName(ctxt);
	    ns = xmlSearchNs(NULL, ctxt->elem, prefix);
	    if (ns == NULL) {
		ERROR5(NULL, NULL, NULL,
	    "xmlCompileStepPattern : no namespace bound to prefix %s\n",
				 prefix);
		ctxt->error = 1;
		goto error;
	    } else {
		URL = xmlStrdup(ns->href);
	    }
	    xmlFree(prefix);
	    if (token == NULL) {
		if (CUR == '*') {
		    NEXT;
		    PUSH(XML_OP_NS, URL, NULL);
		} else {
		    ERROR(NULL, NULL, NULL,
			    "xmlCompileStepPattern : Name expected\n");
		    ctxt->error = 1;
		    goto error;
		}
	    } else {
		PUSH(XML_OP_ELEM, token, URL);
	    }
	} else {
	    NEXT;
	    if (xmlStrEqual(token, (const xmlChar *) "child")) {
		xmlFree(token);
		token = xmlPatScanName(ctxt);
		if (token == NULL) {
	            if (CUR == '*') {
            	        NEXT;
	                PUSH(XML_OP_ALL, token, NULL);
	                return;
	            } else {
		        ERROR(NULL, NULL, NULL,
			    "xmlCompileStepPattern : QName expected\n");
		        ctxt->error = 1;
		        goto error;
		    }
		}
		TODO
		/* URI = xsltGetQNameURI(ctxt->elem, &token); */
		if (token == NULL) {
		    ctxt->error = 1;
		    goto error;
		} else {
		    name = xmlStrdup(token);
		    if (URI != NULL)
			URL = xmlStrdup(URI);
		}
		PUSH(XML_OP_CHILD, name, URL);
	    } else if (xmlStrEqual(token, (const xmlChar *) "attribute")) {
		xmlFree(token);
		token = xmlPatScanName(ctxt);
		if (token == NULL) {
		    ERROR(NULL, NULL, NULL,
			    "xmlCompileStepPattern : QName expected\n");
		    ctxt->error = 1;
		    goto error;
		}
		TODO
		/* URI = xsltGetQNameURI(ctxt->elem, &token); */
		if (token == NULL) {
		    ctxt->error = 1;
		    goto error;
		} else {
		    name = xmlStrdup(token);
		    if (URI != NULL)
			URL = xmlStrdup(URI);
		}
		PUSH(XML_OP_ATTR, name, URL);
	    } else {
		ERROR(NULL, NULL, NULL,
		    "xmlCompileStepPattern : 'child' or 'attribute' expected\n");
		ctxt->error = 1;
		goto error;
	    }
	    xmlFree(token);
	}
    } else if (CUR == '*') {
	NEXT;
	PUSH(XML_OP_ALL, token, NULL);
    } else {
	if (name == NULL) {
	    ctxt->error = 1;
	    goto error;
	}
	PUSH(XML_OP_ELEM, name, NULL);
    }
    return;
error:
    if (token != NULL)
	xmlFree(token);
    if (name != NULL)
	xmlFree(name);
}

/**
 * xmlCompilePathPattern:
 * @ctxt:  the compilation context
 *
 * Compile the Path Pattern and generates a precompiled
 * form suitable for fast matching.
 *
 * [5]    Path    ::=    ('.//')? ( Step '/' )* ( Step | '@' NameTest ) 
 */
static void
xmlCompilePathPattern(xmlPatParserContextPtr ctxt) {
    SKIP_BLANKS;
    if ((CUR == '/') && (NXT(1) == '/')) {
	/*
	 * since we reverse the query
	 * a leading // can be safely ignored
	 */
	NEXT;
	NEXT;
    } else if ((CUR == '.') && (NXT(1) == '/') && (NXT(2) == '/')) {
	/*
	 * a leading .// can be safely ignored
	 */
	NEXT;
	NEXT;
	NEXT;
    }
    if (CUR == '@') {
	TODO
    } else {
	xmlCompileStepPattern(ctxt);
	SKIP_BLANKS;
	while (CUR == '/') {
	    if ((CUR == '/') && (NXT(1) == '/')) {
	        PUSH(XML_OP_ANCESTOR, NULL, NULL);
		NEXT;
		NEXT;
		SKIP_BLANKS;
		xmlCompileStepPattern(ctxt);
	    } else {
	        PUSH(XML_OP_PARENT, NULL, NULL);
		NEXT;
		SKIP_BLANKS;
		if ((CUR != 0) || (CUR == '|')) {
		    xmlCompileStepPattern(ctxt);
		}
	    }
	}
    }
error:
    return;
}
/************************************************************************
 *									*
 *			The public interfaces				*
 *									*
 ************************************************************************/

/**
 * xmlPatterncompile:
 * @pattern: the pattern to compile
 * @dict: an optional dictionnary for interned strings
 * @flags: compilation flags, undefined yet
 * @namespaces: the prefix definitions, array of [URI, prefix] or NULL
 *
 * Compile a pattern.
 *
 * Returns the compiled for of the pattern or NULL in case of error
 */
xmlPatternPtr
xmlPatterncompile(const xmlChar *pattern, xmlDict *dict,
                  int flags ATTRIBUTE_UNUSED,
                  const xmlChar **namespaces) {
    xmlPatternPtr ret = NULL;
    xmlPatParserContextPtr ctxt = NULL;

    ctxt = xmlNewPatParserContext(pattern, dict, namespaces);
    if (ctxt == NULL) goto error;
    ret = xmlNewPattern();
    if (ret == NULL) goto error;
    ctxt->comp = ret;

    xmlCompilePathPattern(ctxt);
    xmlFreePatParserContext(ctxt);

    xmlReversePattern(ret);
    return(ret);
error:
    if (ctxt != NULL) xmlFreePatParserContext(ctxt);
    if (ret != NULL) xmlFreePattern(ret);
    return(NULL);
}

/**
 * xmlPatternMatch:
 * @comp: the precompiled pattern
 * @node: a node
 *
 * Test wether the node matches the pattern
 *
 * Returns 1 if it matches, 0 if it doesn't and -1 in case of failure
 */
int
xmlPatternMatch(xmlPatternPtr comp, xmlNodePtr node)
{
    if ((comp == NULL) || (node == NULL))
        return(-1);
    return(xmlPatMatch(comp, node));
}

#endif /* LIBXML_PATTERN_ENABLED */