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/**
* pugixml parser - version 0.9
* --------------------------------------------------------
* Copyright (C) 2006-2010, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
* Report bugs and download new versions at http://code.google.com/p/pugixml/
*
* This library is distributed under the MIT License. See notice at the end
* of this file.
*
* This work is based on the pugxml parser, which is:
* Copyright (C) 2003, by Kristen Wegner (kristen@tima.net)
*/
/**
* Copyright (c) 2006-2010 Arseny Kapoulkine
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include "pugixml.hpp"
#ifndef PUGIXML_NO_XPATH
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <float.h>
#include <ctype.h>
#include <string.h>
#ifdef PUGIXML_WCHAR_MODE
# include <wchar.h>
#endif
// int32_t
#if !defined(_MSC_VER) || _MSC_VER >= 1600
# include <stdint.h>
#else
typedef __int32 int32_t;
#endif
#if defined(_MSC_VER)
# pragma warning(disable: 4127) // conditional expression is constant
# pragma warning(disable: 4996) // this function or variable may be unsafe
#endif
#ifdef __INTEL_COMPILER
# pragma warning(disable: 1478 1786) // function was declared "deprecated"
#endif
#ifdef __SNC__
# pragma diag_suppress=237 // controlling expression is constant
#endif
#include <algorithm>
#include <string>
// String utilities prototypes
namespace pugi
{
namespace impl
{
bool strequalrange(const char_t* lhs, const char_t* rhs, size_t count);
void widen_ascii(wchar_t* dest, const char* source);
}
}
namespace
{
using namespace pugi;
enum chartypex
{
ctx_space = 1, // \r, \n, space, tab
ctx_start_symbol = 2, // Any symbol > 127, a-z, A-Z, _
ctx_digit = 4, // 0-9
ctx_symbol = 8 // Any symbol > 127, a-z, A-Z, 0-9, _, -, .
};
const unsigned char chartypex_table[256] =
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, // 0-15
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 16-31
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 8, 0, // 32-47
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 0, 0, 0, 0, 0, 0, // 48-63
0, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, // 64-79
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 0, 0, 0, 0, 10, // 80-95
0, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, // 96-111
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 0, 0, 0, 0, 0, // 112-127
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, // 128+
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10
};
#ifdef PUGIXML_WCHAR_MODE
#define IS_CHARTYPEX(c, ct) ((static_cast<unsigned int>(c) < 128 ? chartypex_table[static_cast<unsigned int>(c)] : chartypex_table[128]) & (ct))
#else
#define IS_CHARTYPEX(c, ct) (chartypex_table[static_cast<unsigned char>(c)] & (ct))
#endif
bool starts_with(const char_t* string, const char_t* pattern)
{
while (*pattern && *string == *pattern)
{
string++;
pattern++;
}
return *pattern == 0;
}
const char_t* find_char(const char_t* s, char_t c)
{
#ifdef PUGIXML_WCHAR_MODE
return wcschr(s, c);
#else
return ::strchr(s, c);
#endif
}
string_t string_value(const xpath_node& na)
{
if (na.attribute())
return na.attribute().value();
else
{
const xml_node& n = na.node();
switch (n.type())
{
case node_pcdata:
case node_cdata:
case node_comment:
case node_pi:
return n.value();
case node_document:
case node_element:
{
string_t result;
xml_node cur = n.first_child();
if (cur)
{
do
{
if (cur.type() == node_pcdata || cur.type() == node_cdata)
result += cur.value();
if (cur.first_child())
cur = cur.first_child();
else if (cur.next_sibling())
cur = cur.next_sibling();
else
{
// Borland C++ workaround
while (!cur.next_sibling() && cur != n && (bool)cur.parent())
cur = cur.parent();
if (cur != n)
cur = cur.next_sibling();
}
}
while (cur && cur != n);
}
return result;
}
default:
return string_t();
}
}
}
unsigned int node_height(xml_node n)
{
unsigned int result = 0;
while (n)
{
++result;
n = n.parent();
}
return result;
}
// precondition: node_height of ln is <= node_height of rn, ln != rn
bool node_is_before(xml_node ln, unsigned int lh, xml_node rn, unsigned int rh)
{
assert(lh <= rh);
while (lh < rh)
{
--rh;
rn = rn.parent();
}
if (ln == rn) return true;
while (ln.parent() != rn.parent())
{
ln = ln.parent();
rn = rn.parent();
}
for (; ln; ln = ln.next_sibling())
if (ln == rn)
return true;
return false;
}
bool node_is_ancestor(xml_node parent, xml_node node)
{
while (node && node != parent) node = node.parent();
return parent && node == parent;
}
struct document_order_comparator
{
bool operator()(const xpath_node& lhs, const xpath_node& rhs) const
{
xml_node ln = lhs.node(), rn = rhs.node();
if (lhs.attribute() && rhs.attribute())
{
if (lhs.parent() == rhs.parent())
{
for (xml_attribute a = lhs.attribute(); a; a = a.next_attribute())
if (a == rhs.attribute())
return true;
return false;
}
ln = lhs.parent();
rn = rhs.parent();
}
else if (lhs.attribute())
{
if (lhs.parent() == rhs.node()) return false;
ln = lhs.parent();
}
else if (rhs.attribute())
{
if (rhs.parent() == lhs.node()) return true;
rn = rhs.parent();
}
if (ln == rn) return false;
unsigned int lh = node_height(ln);
unsigned int rh = node_height(rn);
return (lh <= rh) ? node_is_before(ln, lh, rn, rh) : !node_is_before(rn, rh, ln, lh);
}
};
struct duplicate_comparator
{
bool operator()(const xpath_node& lhs, const xpath_node& rhs) const
{
if (lhs.attribute()) return rhs.attribute() ? lhs.attribute() < rhs.attribute() : true;
else return rhs.attribute() ? false : lhs.node() < rhs.node();
}
};
double gen_nan()
{
#if defined(__STDC_IEC_559__) || ((FLT_RADIX - 0 == 2) && (FLT_MAX_EXP - 0 == 128) && (FLT_MANT_DIG - 0 == 24))
union { float f; int32_t i; } u[sizeof(float) == sizeof(int32_t) ? 1 : -1];
u[0].i = 0x7fc00000;
return u[0].f;
#else
// fallback
const volatile double zero = 0.0;
return zero / zero;
#endif
}
bool is_nan(double value)
{
#if defined(_MSC_VER) || defined(__BORLANDC__)
return !!_isnan(value);
#elif defined(fpclassify) && defined(FP_NAN)
return fpclassify(value) == FP_NAN;
#else
// fallback
const volatile double v = value;
return v != v;
#endif
}
const char_t* convert_number_to_string_special(double value)
{
#if defined(_MSC_VER) || defined(__BORLANDC__)
if (_finite(value)) return (value == 0) ? PUGIXML_TEXT("0") : 0;
if (_isnan(value)) return PUGIXML_TEXT("NaN");
return PUGIXML_TEXT("-Infinity") + (value > 0);
#elif defined(fpclassify) && defined(FP_NAN) && defined(FP_INFINITE) && defined(FP_ZERO)
switch (fpclassify(value))
{
case FP_NAN:
return PUGIXML_TEXT("NaN");
case FP_INFINITE:
return PUGIXML_TEXT("-Infinity") + (value > 0);
case FP_ZERO:
return PUGIXML_TEXT("0");
default:
return 0;
}
#else
// fallback
const volatile double v = value;
if (v == 0) return PUGIXML_TEXT("0");
if (v != v) return PUGIXML_TEXT("NaN");
if (v * 2 == v) return PUGIXML_TEXT("-Infinity") + (value > 0);
return 0;
#endif
}
bool convert_number_to_boolean(double value)
{
return (value != 0 && !is_nan(value));
}
// gets mantissa digits in the form of 0.xxxxx with 0. implied and the exponent
void convert_number_to_mantissa_exponent(double value, char* buffer, char** out_mantissa, int* out_exponent)
{
// get a scientific notation value with IEEE DBL_DIG decimals
sprintf(buffer, "%.15e", value);
// get the exponent (possibly negative)
char* exponent_string = strchr(buffer, 'e');
assert(exponent_string);
int exponent = atoi(exponent_string + 1);
// extract mantissa string: skip sign
char* mantissa = buffer[0] == '-' ? buffer + 1 : buffer;
assert(mantissa[0] != '0' && mantissa[1] == '.');
// divide mantissa by 10 to eliminate integer part
mantissa[1] = mantissa[0];
mantissa++;
exponent++;
// remove extra mantissa digits and zero-terminate mantissa
char* mantissa_end = exponent_string;
while (mantissa != mantissa_end && *(mantissa_end - 1) == '0') --mantissa_end;
*mantissa_end = 0;
// fill results
*out_mantissa = mantissa;
*out_exponent = exponent;
}
string_t convert_number_to_string(double value)
{
// try special number conversion
const char_t* special = convert_number_to_string_special(value);
if (special) return special;
// get mantissa + exponent form
char mantissa_buffer[64];
char* mantissa;
int exponent;
convert_number_to_mantissa_exponent(value, mantissa_buffer, &mantissa, &exponent);
// make the number!
char_t result[512];
char_t* s = result;
// sign
if (value < 0) *s++ = '-';
// integer part
if (exponent <= 0)
{
*s++ = '0';
}
else
{
while (exponent > 0)
{
assert(*mantissa == 0 || (unsigned)(*mantissa - '0') <= 9);
*s++ = *mantissa ? *mantissa++ : '0';
exponent--;
}
}
// fractional part
if (*mantissa)
{
// decimal point
*s++ = '.';
// extra zeroes from negative exponent
while (exponent < 0)
{
*s++ = '0';
exponent++;
}
// extra mantissa digits
while (*mantissa)
{
assert((unsigned)(*mantissa - '0') <= 9);
*s++ = *mantissa++;
}
}
// zero-terminate
assert(s < result + sizeof(result) / sizeof(result[0]));
*s = 0;
return string_t(result);
}
bool check_string_to_number_format(const char_t* string)
{
// parse leading whitespace
while (IS_CHARTYPEX(*string, ctx_space)) ++string;
// parse sign
if (*string == '-') ++string;
if (!*string) return false;
// if there is no integer part, there should be a decimal part with at least one digit
if (!IS_CHARTYPEX(string[0], ctx_digit) && (string[0] != '.' || !IS_CHARTYPEX(string[1], ctx_digit))) return false;
// parse integer part
while (IS_CHARTYPEX(*string, ctx_digit)) ++string;
// parse decimal part
if (*string == '.')
{
++string;
while (IS_CHARTYPEX(*string, ctx_digit)) ++string;
}
// parse trailing whitespace
while (IS_CHARTYPEX(*string, ctx_space)) ++string;
return *string == 0;
}
double convert_string_to_number(const char_t* string)
{
// check string format
if (!check_string_to_number_format(string)) return gen_nan();
// parse string
#ifdef PUGIXML_WCHAR_MODE
return wcstod(string, 0);
#else
return atof(string);
#endif
}
double convert_string_to_number(const char_t* begin, const char_t* end)
{
char_t buffer[32];
size_t length = static_cast<size_t>(end - begin);
if (length < sizeof(buffer) / sizeof(buffer[0]))
{
// optimized on-stack conversion
memcpy(buffer, begin, length * sizeof(char_t));
buffer[length] = 0;
return convert_string_to_number(buffer);
}
else
{
// need to make dummy on-heap copy
string_t copy(begin, end);
return convert_string_to_number(copy.c_str());
}
}
double round_nearest(double value)
{
return floor(value + 0.5);
}
double round_nearest_nzero(double value)
{
// same as round_nearest, but returns -0 for [-0.5, -0]
// ceil is used to differentiate between +0 and -0 (we return -0 for [-0.5, -0] and +0 for +0)
return (value >= -0.5 && value <= 0) ? ceil(value) : floor(value + 0.5);
}
const char_t* local_name(const char_t* name)
{
const char_t* p = find_char(name, ':');
return p ? p + 1 : name;
}
const char_t* namespace_uri(const xml_node& node)
{
const char_t* pos = find_char(node.name(), ':');
string_t ns = PUGIXML_TEXT("xmlns");
if (pos)
{
ns += ':';
ns.append(node.name(), pos);
}
xml_node p = node;
while (p)
{
xml_attribute a = p.attribute(ns.c_str());
if (a) return a.value();
p = p.parent();
}
return PUGIXML_TEXT("");
}
const char_t* namespace_uri(const xml_attribute& attr, const xml_node& parent)
{
const char_t* pos = find_char(attr.name(), ':');
// Default namespace does not apply to attributes
if (!pos) return PUGIXML_TEXT("");
string_t ns = PUGIXML_TEXT("xmlns:");
ns.append(attr.name(), pos);
xml_node p = parent;
while (p)
{
xml_attribute a = p.attribute(ns.c_str());
if (a) return a.value();
p = p.parent();
}
return PUGIXML_TEXT("");
}
struct equal_to
{
template <typename T> bool operator()(const T& lhs, const T& rhs) const
{
return lhs == rhs;
}
};
struct not_equal_to
{
template <typename T> bool operator()(const T& lhs, const T& rhs) const
{
return lhs != rhs;
}
};
struct less
{
template <typename T> bool operator()(const T& lhs, const T& rhs) const
{
return lhs < rhs;
}
};
struct less_equal
{
template <typename T> bool operator()(const T& lhs, const T& rhs) const
{
return lhs <= rhs;
}
};
}
namespace pugi
{
xpath_exception::xpath_exception(const char* message): m_message(message)
{
}
const char* xpath_exception::what() const throw()
{
return m_message;
}
const size_t xpath_memory_block_size = 4096; ///< Memory block size, 4 kb
class xpath_allocator
{
// disable copy ctor and assignment
xpath_allocator(const xpath_allocator&);
xpath_allocator& operator=(const xpath_allocator&);
struct memory_block
{
memory_block(): next(0), size(0)
{
}
memory_block* next;
size_t size;
char data[xpath_memory_block_size];
};
memory_block* m_root;
public:
xpath_allocator(): m_root(0)
{
m_root = new memory_block;
}
~xpath_allocator()
{
while (m_root)
{
memory_block* cur = m_root->next;
delete m_root;
m_root = cur;
}
}
void* alloc(size_t size)
{
// align size so that we're able to store pointers in subsequent blocks
size = (size + sizeof(void*) - 1) & ~(sizeof(void*) - 1);
if (m_root->size + size <= xpath_memory_block_size)
{
void* buf = m_root->data + m_root->size;
m_root->size += size;
return buf;
}
else
{
memory_block* block;
if (size > xpath_memory_block_size)
block = static_cast<memory_block*>(operator new(size + sizeof(memory_block) - xpath_memory_block_size));
else
block = new memory_block;
block->next = m_root;
block->size = size;
m_root = block;
return block->data;
}
}
void* node();
};
xpath_node::xpath_node()
{
}
xpath_node::xpath_node(const xml_node& node): m_node(node)
{
}
xpath_node::xpath_node(const xml_attribute& attribute, const xml_node& parent): m_node(parent), m_attribute(attribute)
{
}
xml_node xpath_node::node() const
{
return m_attribute ? xml_node() : m_node;
}
xml_attribute xpath_node::attribute() const
{
return m_attribute;
}
xml_node xpath_node::parent() const
{
return m_attribute ? m_node : m_node.parent();
}
xpath_node::operator xpath_node::unspecified_bool_type() const
{
return (m_node || m_attribute) ? &xpath_node::m_node : 0;
}
bool xpath_node::operator!() const
{
return !(m_node || m_attribute);
}
bool xpath_node::operator==(const xpath_node& n) const
{
return m_node == n.m_node && m_attribute == n.m_attribute;
}
bool xpath_node::operator!=(const xpath_node& n) const
{
return m_node != n.m_node || m_attribute != n.m_attribute;
}
#ifdef __BORLANDC__
bool operator&&(const xpath_node& lhs, bool rhs)
{
return (bool)lhs && rhs;
}
bool operator||(const xpath_node& lhs, bool rhs)
{
return (bool)lhs || rhs;
}
#endif
xpath_node_set::xpath_node_set(): m_type(type_unsorted), m_begin(&m_storage), m_end(&m_storage), m_eos(&m_storage + 1)
{
}
xpath_node_set::~xpath_node_set()
{
if (m_begin != &m_storage) delete[] m_begin;
}
xpath_node_set::xpath_node_set(const xpath_node_set& ns): m_type(type_unsorted), m_begin(&m_storage), m_end(&m_storage), m_eos(&m_storage + 1)
{
*this = ns;
}
xpath_node_set& xpath_node_set::operator=(const xpath_node_set& ns)
{
if (&ns == this) return *this;
if (m_begin != &m_storage) delete[] m_begin;
m_begin = m_end = m_eos = 0;
m_type = ns.m_type;
if (ns.size() == 1)
{
m_storage = *ns.m_begin;
m_begin = &m_storage;
m_end = m_eos = &m_storage + 1;
}
else
{
append(ns.begin(), ns.end());
}
return *this;
}
xpath_node_set::type_t xpath_node_set::type() const
{
return m_type;
}
size_t xpath_node_set::size() const
{
return m_end - m_begin;
}
bool xpath_node_set::empty() const
{
return size() == 0;
}
const xpath_node& xpath_node_set::operator[](size_t index) const
{
assert(index < size());
return m_begin[index];
}
xpath_node_set::iterator xpath_node_set::mut_begin()
{
return m_begin;
}
xpath_node_set::const_iterator xpath_node_set::begin() const
{
return m_begin;
}
xpath_node_set::const_iterator xpath_node_set::end() const
{
return m_end;
}
void xpath_node_set::sort(bool reverse)
{
std::sort(m_begin, m_end, document_order_comparator());
if (reverse)
std::reverse(m_begin, m_end);
m_type = reverse ? type_sorted_reverse : type_sorted;
}
void xpath_node_set::push_back(const xpath_node& n)
{
if (m_end == m_eos)
append(&n, &n + 1);
else
{
*m_end = n;
++m_end;
}
}
void xpath_node_set::append(const_iterator begin, const_iterator end)
{
if (begin == end) return;
size_t count = end - begin;
size_t size = m_end - m_begin;
size_t capacity = m_eos - m_begin;
if (capacity < size + count)
{
if (capacity < 2) capacity = 2;
while (capacity < size + count) capacity += capacity / 2;
xpath_node* storage = new xpath_node[capacity];
std::copy(m_begin, m_end, storage);
if (m_begin != &m_storage) delete[] m_begin;
m_begin = storage;
m_end = storage + size;
m_eos = storage + capacity;
}
std::copy(begin, end, m_end);
m_end += count;
}
void xpath_node_set::truncate(iterator it)
{
m_end = it;
}
xpath_node xpath_node_set::first() const
{
if (empty()) return xpath_node();
switch (m_type)
{
case type_sorted: return *m_begin;
case type_sorted_reverse: return *(m_end - 1);
case type_unsorted: return *std::min_element(begin(), end(), document_order_comparator());
default: return xpath_node();
}
}
void xpath_node_set::remove_duplicates()
{
if (m_type == type_unsorted)
{
std::sort(m_begin, m_end, duplicate_comparator());
}
truncate(std::unique(m_begin, m_end));
}
struct xpath_context
{
xml_node root;
xpath_node n;
size_t position, size;
};
enum lexeme_t
{
lex_none = 0,
lex_equal,
lex_not_equal,
lex_less,
lex_greater,
lex_less_or_equal,
lex_greater_or_equal,
lex_plus,
lex_minus,
lex_multiply,
lex_union,
lex_var_ref,
lex_open_brace,
lex_close_brace,
lex_quoted_string,
lex_number,
lex_slash,
lex_double_slash,
lex_open_square_brace,
lex_close_square_brace,
lex_string,
lex_comma,
lex_axis_attribute,
lex_dot,
lex_double_dot,
lex_double_colon,
lex_eof
};
struct xpath_lexer_string
{
const char_t* begin;
const char_t* end;
xpath_lexer_string(): begin(0), end(0)
{
}
bool operator==(const char_t* other) const
{
size_t length = static_cast<size_t>(end - begin);
return impl::strequalrange(other, begin, length);
}
};
class xpath_lexer
{
// disable copy ctor and assignment
xpath_lexer(const xpath_lexer&);
xpath_lexer& operator=(const xpath_lexer&);
private:
const char_t* m_cur;
xpath_lexer_string m_cur_lexeme_contents;
lexeme_t m_cur_lexeme;
void contents_clear()
{
m_cur_lexeme_contents = xpath_lexer_string();
}
public:
explicit xpath_lexer(const char_t* query): m_cur(query)
{
next();
}
const char_t* state() const
{
return m_cur;
}
void next()
{
contents_clear();
const char_t* cur = m_cur;
while (IS_CHARTYPEX(*cur, ctx_space)) ++cur;
switch (*cur)
{
case 0:
m_cur_lexeme = lex_eof;
break;
case '>':
if (*(cur+1) == '=')
{
cur += 2;
m_cur_lexeme = lex_greater_or_equal;
}
else
{
cur += 1;
m_cur_lexeme = lex_greater;
}
break;
case '<':
if (*(cur+1) == '=')
{
cur += 2;
m_cur_lexeme = lex_less_or_equal;
}
else
{
cur += 1;
m_cur_lexeme = lex_less;
}
break;
case '!':
if (*(cur+1) == '=')
{
cur += 2;
m_cur_lexeme = lex_not_equal;
}
else
{
m_cur_lexeme = lex_none;
}
break;
case '=':
cur += 1;
m_cur_lexeme = lex_equal;
break;
case '+':
cur += 1;
m_cur_lexeme = lex_plus;
break;
case '-':
cur += 1;
m_cur_lexeme = lex_minus;
break;
case '*':
cur += 1;
m_cur_lexeme = lex_multiply;
break;
case '|':
cur += 1;
m_cur_lexeme = lex_union;
break;
case '$':
cur += 1;
m_cur_lexeme = lex_var_ref;
break;
case '(':
cur += 1;
m_cur_lexeme = lex_open_brace;
break;
case ')':
cur += 1;
m_cur_lexeme = lex_close_brace;
break;
case '[':
cur += 1;
m_cur_lexeme = lex_open_square_brace;
break;
case ']':
cur += 1;
m_cur_lexeme = lex_close_square_brace;
break;
case ',':
cur += 1;
m_cur_lexeme = lex_comma;
break;
case '/':
if (*(cur+1) == '/')
{
cur += 2;
m_cur_lexeme = lex_double_slash;
}
else
{
cur += 1;
m_cur_lexeme = lex_slash;
}
break;
case '.':
if (*(cur+1) == '.')
{
cur += 2;
m_cur_lexeme = lex_double_dot;
}
else if (IS_CHARTYPEX(*(cur+1), ctx_digit))
{
m_cur_lexeme_contents.begin = cur; // .
++cur;
while (IS_CHARTYPEX(*cur, ctx_digit)) cur++;
m_cur_lexeme_contents.end = cur;
m_cur_lexeme = lex_number;
}
else
{
cur += 1;
m_cur_lexeme = lex_dot;
}
break;
case '@':
cur += 1;
m_cur_lexeme = lex_axis_attribute;
break;
case '"':
case '\'':
{
char_t terminator = *cur;
++cur;
m_cur_lexeme_contents.begin = cur;
while (*cur && *cur != terminator) cur++;
m_cur_lexeme_contents.end = cur;
if (!*cur)
m_cur_lexeme = lex_none;
else
{
cur += 1;
m_cur_lexeme = lex_quoted_string;
}
break;
}
case ':':
if (*(cur+1) == ':')
{
cur += 2;
m_cur_lexeme = lex_double_colon;
}
else
{
m_cur_lexeme = lex_none;
}
break;
default:
if (IS_CHARTYPEX(*cur, ctx_digit))
{
m_cur_lexeme_contents.begin = cur;
while (IS_CHARTYPEX(*cur, ctx_digit)) cur++;
if (*cur == '.')
{
cur++;
while (IS_CHARTYPEX(*cur, ctx_digit)) cur++;
}
m_cur_lexeme_contents.end = cur;
m_cur_lexeme = lex_number;
}
else if (IS_CHARTYPEX(*cur, ctx_start_symbol))
{
m_cur_lexeme_contents.begin = cur;
while (IS_CHARTYPEX(*cur, ctx_symbol)) cur++;
if (cur[0] == ':')
{
if (cur[1] == '*') // namespace test ncname:*
{
cur += 2; // :*
}
else if (IS_CHARTYPEX(cur[1], ctx_symbol)) // namespace test qname
{
cur++; // :
while (IS_CHARTYPEX(*cur, ctx_symbol)) cur++;
}
}
m_cur_lexeme_contents.end = cur;
while (IS_CHARTYPEX(*cur, ctx_space)) ++cur;
m_cur_lexeme = lex_string;
}
else
{
throw xpath_exception("Unrecognized token");
}
}
m_cur = cur;
}
lexeme_t current() const
{
return m_cur_lexeme;
}
const xpath_lexer_string& contents() const
{
return m_cur_lexeme_contents;
}
};
enum ast_type_t
{
ast_none,
ast_op_or, // left or right
ast_op_and, // left and right
ast_op_equal, // left = right
ast_op_not_equal, // left != right
ast_op_less, // left < right
ast_op_greater, // left > right
ast_op_less_or_equal, // left <= right
ast_op_greater_or_equal, // left >= right
ast_op_add, // left + right
ast_op_subtract, // left - right
ast_op_multiply, // left * right
ast_op_divide, // left / right
ast_op_mod, // left % right
ast_op_negate, // left - right
ast_op_union, // left | right
ast_predicate, // apply predicate to set; next points to next predicate
ast_filter, // select * from left where right
ast_filter_posinv, // select * from left where right; proximity position invariant
ast_string_constant, // string constant
ast_number_constant, // number constant
ast_func_last, // last()
ast_func_position, // position()
ast_func_count, // count(left)
ast_func_id, // id(left)
ast_func_local_name_0, // local-name()
ast_func_local_name_1, // local-name(left)
ast_func_namespace_uri_0, // namespace-uri()
ast_func_namespace_uri_1, // namespace-uri(left)
ast_func_name_0, // name()
ast_func_name_1, // name(left)
ast_func_string_0, // string()
ast_func_string_1, // string(left)
ast_func_concat, // concat(left, right, siblings)
ast_func_starts_with, // starts_with(left, right)
ast_func_contains, // contains(left, right)
ast_func_substring_before, // substring-before(left, right)
ast_func_substring_after, // substring-after(left, right)
ast_func_substring_2, // substring(left, right)
ast_func_substring_3, // substring(left, right, third)
ast_func_string_length_0, // string-length()
ast_func_string_length_1, // string-length(left)
ast_func_normalize_space_0, // normalize-space()
ast_func_normalize_space_1, // normalize-space(left)
ast_func_translate, // translate(left, right, third)
ast_func_boolean, // boolean(left)
ast_func_not, // not(left)
ast_func_true, // true()
ast_func_false, // false()
ast_func_lang, // lang(left)
ast_func_number_0, // number()
ast_func_number_1, // number(left)
ast_func_sum, // sum(left)
ast_func_floor, // floor(left)
ast_func_ceiling, // ceiling(left)
ast_func_round, // round(left)
ast_step, // process set left with step
ast_step_root // select root node
};
enum axis_t
{
axis_ancestor,
axis_ancestor_or_self,
axis_attribute,
axis_child,
axis_descendant,
axis_descendant_or_self,
axis_following,
axis_following_sibling,
axis_namespace,
axis_parent,
axis_preceding,
axis_preceding_sibling,
axis_self
};
enum nodetest_t
{
nodetest_none,
nodetest_name,
nodetest_type_node,
nodetest_type_comment,
nodetest_type_pi,
nodetest_type_text,
nodetest_pi,
nodetest_all,
nodetest_all_in_namespace
};
template <axis_t N> struct axis_to_type
{
static const axis_t axis;
};
template <axis_t N> const axis_t axis_to_type<N>::axis = N;
class xpath_ast_node
{
private:
// node type
char m_type;
char m_rettype;
// for ast_step / ast_predicate
char m_axis;
char m_test;
// tree node structure
xpath_ast_node* m_left;
xpath_ast_node* m_right;
xpath_ast_node* m_next;
union
{
// value for ast_string_constant
const char_t* string;
// value for ast_number_constant
double number;
// node test for ast_step (node name/namespace/node type/pi target)
const char_t* nodetest;
} m_data;
xpath_ast_node(const xpath_ast_node&);
xpath_ast_node& operator=(const xpath_ast_node&);
template <class Comp> static bool compare_eq(xpath_ast_node* lhs, xpath_ast_node* rhs, const xpath_context& c, const Comp& comp)
{
xpath_value_type lt = lhs->rettype(), rt = rhs->rettype();
if (lt != xpath_type_node_set && rt != xpath_type_node_set)
{
if (lt == xpath_type_boolean || rt == xpath_type_boolean)
return comp(lhs->eval_boolean(c), rhs->eval_boolean(c));
else if (lt == xpath_type_number || rt == xpath_type_number)
return comp(lhs->eval_number(c), rhs->eval_number(c));
else if (lt == xpath_type_string || rt == xpath_type_string)
return comp(lhs->eval_string(c), rhs->eval_string(c));
}
else if (lt == xpath_type_node_set && rt == xpath_type_node_set)
{
xpath_node_set ls = lhs->eval_node_set(c);
xpath_node_set rs = rhs->eval_node_set(c);
for (xpath_node_set::const_iterator li = ls.begin(); li != ls.end(); ++li)
for (xpath_node_set::const_iterator ri = rs.begin(); ri != rs.end(); ++ri)
{
if (comp(string_value(*li), string_value(*ri)))
return true;
}
return false;
}
else
{
if (lt == xpath_type_node_set)
{
std::swap(lhs, rhs);
std::swap(lt, rt);
}
if (lt == xpath_type_boolean)
return comp(lhs->eval_boolean(c), rhs->eval_boolean(c));
else if (lt == xpath_type_number)
{
double l = lhs->eval_number(c);
xpath_node_set rs = rhs->eval_node_set(c);
for (xpath_node_set::const_iterator ri = rs.begin(); ri != rs.end(); ++ri)
{
if (comp(l, convert_string_to_number(string_value(*ri).c_str())))
return true;
}
return false;
}
else if (lt == xpath_type_string)
{
string_t l = lhs->eval_string(c);
xpath_node_set rs = rhs->eval_node_set(c);
for (xpath_node_set::const_iterator ri = rs.begin(); ri != rs.end(); ++ri)
{
if (comp(l, string_value(*ri)))
return true;
}
return false;
}
}
assert(!"Wrong types");
return false;
}
template <class Comp> static bool compare_rel(xpath_ast_node* lhs, xpath_ast_node* rhs, const xpath_context& c, const Comp& comp)
{
xpath_value_type lt = lhs->rettype(), rt = rhs->rettype();
if (lt != xpath_type_node_set && rt != xpath_type_node_set)
return comp(lhs->eval_number(c), rhs->eval_number(c));
else if (lt == xpath_type_node_set && rt == xpath_type_node_set)
{
xpath_node_set ls = lhs->eval_node_set(c);
xpath_node_set rs = rhs->eval_node_set(c);
for (xpath_node_set::const_iterator li = ls.begin(); li != ls.end(); ++li)
{
double l = convert_string_to_number(string_value(*li).c_str());
for (xpath_node_set::const_iterator ri = rs.begin(); ri != rs.end(); ++ri)
{
if (comp(l, convert_string_to_number(string_value(*ri).c_str())))
return true;
}
}
return false;
}
else if (lt != xpath_type_node_set && rt == xpath_type_node_set)
{
double l = lhs->eval_number(c);
xpath_node_set rs = rhs->eval_node_set(c);
for (xpath_node_set::const_iterator ri = rs.begin(); ri != rs.end(); ++ri)
{
if (comp(l, convert_string_to_number(string_value(*ri).c_str())))
return true;
}
return false;
}
else if (lt == xpath_type_node_set && rt != xpath_type_node_set)
{
xpath_node_set ls = lhs->eval_node_set(c);
double r = rhs->eval_number(c);
for (xpath_node_set::const_iterator li = ls.begin(); li != ls.end(); ++li)
{
if (comp(convert_string_to_number(string_value(*li).c_str()), r))
return true;
}
return false;
}
else
{
assert(!"Wrong types");
return false;
}
}
void apply_predicate(xpath_node_set& ns, size_t first, xpath_ast_node* expr, const xpath_context& context)
{
xpath_context c;
c.root = context.root;
size_t i = 1;
size_t size = ns.size() - first;
xpath_node_set::iterator last = ns.mut_begin() + first;
// remove_if... or well, sort of
for (xpath_node_set::iterator it = last; it != ns.end(); ++it, ++i)
{
c.n = *it;
c.position = i;
c.size = size;
if (expr->rettype() == xpath_type_number)
{
if (expr->eval_number(c) == i)
*last++ = *it;
}
else if (expr->eval_boolean(c))
*last++ = *it;
}
ns.truncate(last);
}
void apply_predicates(xpath_node_set& ns, size_t first, const xpath_context& context)
{
if (ns.size() <= first) return;
for (xpath_ast_node* pred = m_right; pred; pred = pred->m_next)
{
apply_predicate(ns, first, pred->m_left, context);
}
}
void step_push(xpath_node_set& ns, const xml_attribute& a, const xml_node& parent)
{
if (!a) return;
const char_t* name = a.name();
// There are no attribute nodes corresponding to attributes that declare namespaces
// That is, "xmlns:..." or "xmlns"
if (starts_with(name, PUGIXML_TEXT("xmlns")) && (name[5] == 0 || name[5] == ':')) return;
switch (m_test)
{
case nodetest_name:
if (impl::strequal(name, m_data.nodetest)) ns.push_back(xpath_node(a, parent));
break;
case nodetest_type_node:
case nodetest_all:
ns.push_back(xpath_node(a, parent));
break;
case nodetest_all_in_namespace:
if (starts_with(name, m_data.nodetest))
ns.push_back(xpath_node(a, parent));
break;
default:
;
}
}
void step_push(xpath_node_set& ns, const xml_node& n)
{
if (!n) return;
switch (m_test)
{
case nodetest_name:
if (n.type() == node_element && impl::strequal(n.name(), m_data.nodetest)) ns.push_back(n);
break;
case nodetest_type_node:
ns.push_back(n);
break;
case nodetest_type_comment:
if (n.type() == node_comment)
ns.push_back(n);
break;
case nodetest_type_text:
if (n.type() == node_pcdata || n.type() == node_cdata)
ns.push_back(n);
break;
case nodetest_type_pi:
if (n.type() == node_pi)
ns.push_back(n);
break;
case nodetest_pi:
if (n.type() == node_pi && impl::strequal(n.name(), m_data.nodetest))
ns.push_back(n);
break;
case nodetest_all:
if (n.type() == node_element)
ns.push_back(n);
break;
case nodetest_all_in_namespace:
if (n.type() == node_element && starts_with(n.name(), m_data.nodetest))
ns.push_back(n);
break;
default:
assert(!"Unknown axis");
}
}
template <class T> void step_fill(xpath_node_set& ns, const xml_node& n, T)
{
const axis_t axis = T::axis;
switch (axis)
{
case axis_attribute:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
for (xml_attribute a = n.first_attribute(); a; a = a.next_attribute())
step_push(ns, a, n);
break;
}
case axis_child:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
for (xml_node c = n.first_child(); c; c = c.next_sibling())
step_push(ns, c);
break;
}
case axis_descendant:
case axis_descendant_or_self:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
if (axis == axis_descendant_or_self)
step_push(ns, n);
xml_node cur = n.first_child();
if (cur)
{
do
{
step_push(ns, cur);
if (cur.first_child())
cur = cur.first_child();
else if (cur.next_sibling())
cur = cur.next_sibling();
else
{
// Borland C++ workaround
while (!cur.next_sibling() && cur != n && (bool)cur.parent())
cur = cur.parent();
if (cur != n)
cur = cur.next_sibling();
}
}
while (cur && cur != n);
}
break;
}
case axis_following_sibling:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
for (xml_node c = n.next_sibling(); c; c = c.next_sibling())
step_push(ns, c);
break;
}
case axis_preceding_sibling:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_unsorted;
for (xml_node c = n.previous_sibling(); c; c = c.previous_sibling())
step_push(ns, c);
break;
}
case axis_following:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
xml_node cur = n;
// exit from this node so that we don't include descendants
while (cur && !cur.next_sibling()) cur = cur.parent();
cur = cur.next_sibling();
if (cur)
{
for (;;)
{
step_push(ns, cur);
if (cur.first_child())
cur = cur.first_child();
else if (cur.next_sibling())
cur = cur.next_sibling();
else
{
while (cur && !cur.next_sibling()) cur = cur.parent();
cur = cur.next_sibling();
if (!cur) break;
}
}
}
break;
}
case axis_preceding:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_unsorted;
xml_node cur = n;
while (cur && !cur.previous_sibling()) cur = cur.parent();
cur = cur.previous_sibling();
if (cur)
{
for (;;)
{
if (cur.last_child())
cur = cur.last_child();
else
{
// leaf node, can't be ancestor
step_push(ns, cur);
if (cur.previous_sibling())
cur = cur.previous_sibling();
else
{
do
{
cur = cur.parent();
if (!cur) break;
if (!node_is_ancestor(cur, n)) step_push(ns, cur);
}
while (!cur.previous_sibling());
cur = cur.previous_sibling();
if (!cur) break;
}
}
}
}
break;
}
case axis_ancestor:
case axis_ancestor_or_self:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_unsorted;
if (axis == axis_ancestor_or_self)
step_push(ns, n);
xml_node cur = n.parent();
while (cur)
{
step_push(ns, cur);
cur = cur.parent();
}
break;
}
case axis_self:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
step_push(ns, n);
break;
}
case axis_parent:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
if (n.parent()) step_push(ns, n.parent());
break;
}
default:
assert(!"Unimplemented axis");
}
}
template <class T> void step_fill(xpath_node_set& ns, const xml_attribute& a, const xml_node& p, T v)
{
const axis_t axis = T::axis;
switch (axis)
{
case axis_ancestor:
case axis_ancestor_or_self:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_unsorted;
if (axis == axis_ancestor_or_self && m_test == nodetest_type_node) // reject attributes based on principal node type test
step_push(ns, a, p);
xml_node cur = p;
while (cur)
{
step_push(ns, cur);
cur = cur.parent();
}
break;
}
case axis_descendant_or_self:
case axis_self:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
if (m_test == nodetest_type_node) // reject attributes based on principal node type test
step_push(ns, a, p);
break;
}
case axis_following:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
xml_node cur = p;
for (;;)
{
if (cur.first_child())
cur = cur.first_child();
else if (cur.next_sibling())
cur = cur.next_sibling();
else
{
while (cur && !cur.next_sibling()) cur = cur.parent();
cur = cur.next_sibling();
if (!cur) break;
}
step_push(ns, cur);
}
break;
}
case axis_parent:
{
ns.m_type = ns.empty() ? xpath_node_set::type_sorted : xpath_node_set::type_unsorted;
step_push(ns, p);
break;
}
case axis_preceding:
{
// preceding:: axis does not include attribute nodes and attribute ancestors (they are the same as parent's ancestors), so we can reuse node preceding
step_fill(ns, p, v);
break;
}
default:
assert(!"Unimplemented axis");
}
}
template <class T> void step_do(xpath_node_set& ns, const xpath_context& c, T v)
{
const axis_t axis = T::axis;
assert(ns.empty());
switch (axis)
{
case axis_ancestor:
case axis_ancestor_or_self:
case axis_descendant_or_self:
case axis_following:
case axis_parent:
case axis_preceding:
case axis_self:
if (m_left)
{
xpath_node_set s = m_left->eval_node_set(c);
for (xpath_node_set::const_iterator it = s.begin(); it != s.end(); ++it)
{
size_t size = ns.size();
if (it->node())
step_fill(ns, it->node(), v);
else
step_fill(ns, it->attribute(), it->parent(), v);
apply_predicates(ns, size, c);
}
}
else
{
if (c.n.node()) step_fill(ns, c.n.node(), v);
else step_fill(ns, c.n.attribute(), c.n.parent(), v);
apply_predicates(ns, 0, c);
}
break;
case axis_following_sibling:
case axis_preceding_sibling:
case axis_attribute:
case axis_child:
case axis_descendant:
if (m_left)
{
xpath_node_set s = m_left->eval_node_set(c);
for (xpath_node_set::const_iterator it = s.begin(); it != s.end(); ++it)
{
size_t size = ns.size();
if (it->node())
step_fill(ns, it->node(), v);
apply_predicates(ns, size, c);
}
}
else if (c.n.node())
{
step_fill(ns, c.n.node(), v);
apply_predicates(ns, 0, c);
}
break;
case axis_namespace:
break;
default:
assert(!"Unimplemented axis");
}
}
static const char_t* duplicate_string(const xpath_lexer_string& value, xpath_allocator& a)
{
if (value.begin)
{
size_t length = static_cast<size_t>(value.end - value.begin);
char_t* c = static_cast<char_t*>(a.alloc((length + 1) * sizeof(char_t)));
memcpy(c, value.begin, length * sizeof(char_t));
c[length] = 0;
return c;
}
else return 0;
}
public:
xpath_ast_node(ast_type_t type, xpath_value_type rettype, const xpath_lexer_string& value, xpath_allocator& a):
m_type((char)type), m_rettype((char)rettype), m_axis(0), m_test(0), m_left(0), m_right(0), m_next(0)
{
assert(type == ast_string_constant);
m_data.string = duplicate_string(value, a);
}
xpath_ast_node(ast_type_t type, xpath_value_type rettype, double value):
m_type((char)type), m_rettype((char)rettype), m_axis(0), m_test(0), m_left(0), m_right(0), m_next(0)
{
assert(type == ast_number_constant);
m_data.number = value;
}
xpath_ast_node(ast_type_t type, xpath_value_type rettype, xpath_ast_node* left = 0, xpath_ast_node* right = 0):
m_type((char)type), m_rettype((char)rettype), m_axis(0), m_test(0), m_left(left), m_right(right), m_next(0)
{
}
xpath_ast_node(ast_type_t type, xpath_ast_node* left, axis_t axis, nodetest_t test, const xpath_lexer_string& contents, xpath_allocator& a):
m_type((char)type), m_rettype(xpath_type_node_set), m_axis((char)axis), m_test((char)test), m_left(left), m_right(0), m_next(0)
{
m_data.nodetest = duplicate_string(contents, a);
}
void set_next(xpath_ast_node* value)
{
m_next = value;
}
void set_right(xpath_ast_node* value)
{
m_right = value;
}
bool eval_boolean(const xpath_context& c)
{
switch (m_type)
{
case ast_op_or:
if (m_left->eval_boolean(c)) return true;
else return m_right->eval_boolean(c);
case ast_op_and:
if (!m_left->eval_boolean(c)) return false;
else return m_right->eval_boolean(c);
case ast_op_equal:
return compare_eq(m_left, m_right, c, equal_to());
case ast_op_not_equal:
return compare_eq(m_left, m_right, c, not_equal_to());
case ast_op_less:
return compare_rel(m_left, m_right, c, less());
case ast_op_greater:
return compare_rel(m_right, m_left, c, less());
case ast_op_less_or_equal:
return compare_rel(m_left, m_right, c, less_equal());
case ast_op_greater_or_equal:
return compare_rel(m_right, m_left, c, less_equal());
case ast_func_starts_with:
return starts_with(m_left->eval_string(c).c_str(), m_right->eval_string(c).c_str());
case ast_func_contains:
{
string_t lr = m_left->eval_string(c);
string_t rr = m_right->eval_string(c);
return rr.empty() || lr.find(rr) != string_t::npos;
}
case ast_func_boolean:
return m_left->eval_boolean(c);
case ast_func_not:
return !m_left->eval_boolean(c);
case ast_func_true:
return true;
case ast_func_false:
return false;
case ast_func_lang:
{
if (c.n.attribute()) return false;
string_t lang = m_left->eval_string(c);
for (xml_node n = c.n.node(); n; n = n.parent())
{
xml_attribute a = n.attribute(PUGIXML_TEXT("xml:lang"));
if (a)
{
const char_t* value = a.value();
// strnicmp / strncasecmp is not portable
for (const char_t* lit = lang.c_str(); *lit; ++lit)
{
if (tolower(*lit) != tolower(*value)) return false;
++value;
}
return *value == 0 || *value == '-';
}
}
return false;
}
default:
{
switch (m_rettype)
{
case xpath_type_number:
return convert_number_to_boolean(eval_number(c));
case xpath_type_string:
return !eval_string(c).empty();
case xpath_type_node_set:
return !eval_node_set(c).empty();
default:
assert(!"Wrong expression for return type boolean");
return false;
}
}
}
}
double eval_number(const xpath_context& c)
{
switch (m_type)
{
case ast_op_add:
return m_left->eval_number(c) + m_right->eval_number(c);
case ast_op_subtract:
return m_left->eval_number(c) - m_right->eval_number(c);
case ast_op_multiply:
return m_left->eval_number(c) * m_right->eval_number(c);
case ast_op_divide:
return m_left->eval_number(c) / m_right->eval_number(c);
case ast_op_mod:
return fmod(m_left->eval_number(c), m_right->eval_number(c));
case ast_op_negate:
return -m_left->eval_number(c);
case ast_number_constant:
return m_data.number;
case ast_func_last:
return (double)c.size;
case ast_func_position:
return (double)c.position;
case ast_func_count:
return (double)m_left->eval_node_set(c).size();
case ast_func_string_length_0:
return (double)string_value(c.n).size();
case ast_func_string_length_1:
return (double)m_left->eval_string(c).size();
case ast_func_number_0:
return convert_string_to_number(string_value(c.n).c_str());
case ast_func_number_1:
return m_left->eval_number(c);
case ast_func_sum:
{
double r = 0;
xpath_node_set ns = m_left->eval_node_set(c);
for (xpath_node_set::const_iterator it = ns.begin(); it != ns.end(); ++it)
r += convert_string_to_number(string_value(*it).c_str());
return r;
}
case ast_func_floor:
{
double r = m_left->eval_number(c);
return r == r ? floor(r) : r;
}
case ast_func_ceiling:
{
double r = m_left->eval_number(c);
return r == r ? ceil(r) : r;
}
case ast_func_round:
return round_nearest_nzero(m_left->eval_number(c));
default:
{
switch (m_rettype)
{
case xpath_type_boolean:
return eval_boolean(c) ? 1 : 0;
case xpath_type_string:
return convert_string_to_number(eval_string(c).c_str());
case xpath_type_node_set:
return convert_string_to_number(eval_string(c).c_str());
default:
assert(!"Wrong expression for return type number");
return 0;
}
}
}
}
string_t eval_string(const xpath_context& c)
{
switch (m_type)
{
case ast_string_constant:
return m_data.string;
case ast_func_local_name_0:
{
xpath_node na = c.n;
if (na.attribute()) return local_name(na.attribute().name());
else return local_name(na.node().name());
}
case ast_func_local_name_1:
{
xpath_node_set ns = m_left->eval_node_set(c);
if (ns.empty()) return string_t();
xpath_node na = ns.first();
if (na.attribute()) return local_name(na.attribute().name());
else return local_name(na.node().name());
}
case ast_func_name_0:
{
xpath_node na = c.n;
if (na.attribute()) return na.attribute().name();
else return na.node().name();
}
case ast_func_name_1:
{
xpath_node_set ns = m_left->eval_node_set(c);
if (ns.empty()) return string_t();
xpath_node na = ns.first();
if (na.attribute()) return na.attribute().name();
else return na.node().name();
}
case ast_func_namespace_uri_0:
{
xpath_node na = c.n;
if (na.attribute()) return namespace_uri(na.attribute(), na.parent());
else return namespace_uri(na.node());
}
case ast_func_namespace_uri_1:
{
xpath_node_set ns = m_left->eval_node_set(c);
if (ns.empty()) return string_t();
xpath_node na = ns.first();
if (na.attribute()) return namespace_uri(na.attribute(), na.parent());
else return namespace_uri(na.node());
}
case ast_func_string_0:
return string_value(c.n);
case ast_func_string_1:
return m_left->eval_string(c);
case ast_func_concat:
{
string_t r = m_left->eval_string(c);
for (xpath_ast_node* n = m_right; n; n = n->m_next)
r += n->eval_string(c);
return r;
}
case ast_func_substring_before:
{
string_t s = m_left->eval_string(c);
string_t::size_type pos = s.find(m_right->eval_string(c));
if (pos == string_t::npos) return string_t();
else return string_t(s.begin(), s.begin() + pos);
}
case ast_func_substring_after:
{
string_t s = m_left->eval_string(c);
string_t p = m_right->eval_string(c);
string_t::size_type pos = s.find(p);
if (pos == string_t::npos) return string_t();
else return string_t(s.begin() + pos + p.length(), s.end());
}
case ast_func_substring_2:
{
string_t s = m_left->eval_string(c);
double first = round_nearest(m_right->eval_number(c));
if (is_nan(first)) return string_t(); // NaN
else if (first >= s.length() + 1) return string_t();
size_t pos = first < 1 ? 1 : (size_t)first;
return s.substr(pos - 1);
}
case ast_func_substring_3:
{
string_t s = m_left->eval_string(c);
double first = round_nearest(m_right->eval_number(c));
double last = first + round_nearest(m_right->m_next->eval_number(c));
if (is_nan(first) || is_nan(last)) return string_t();
else if (first >= s.length() + 1) return string_t();
else if (first >= last) return string_t();
size_t pos = first < 1 ? 1 : (size_t)first;
size_t end = last >= s.length() + 1 ? s.length() + 1 : (size_t)last;
size_t size_requested = end - pos;
size_t size_to_end = s.length() - pos + 1;
return s.substr(pos - 1, size_requested < size_to_end ? size_requested : size_to_end);
}
case ast_func_normalize_space_0:
case ast_func_normalize_space_1:
{
string_t s = m_type == ast_func_normalize_space_0 ? string_value(c.n) : m_left->eval_string(c);
string_t r;
r.reserve(s.size());
for (string_t::const_iterator it = s.begin(); it != s.end(); ++it)
{
if (IS_CHARTYPEX(*it, ctx_space))
{
if (!r.empty() && r[r.size() - 1] != ' ')
r += ' ';
}
else r += *it;
}
string_t::size_type pos = r.find_last_not_of(' ');
if (pos == string_t::npos) r = string_t();
else r.erase(r.begin() + pos + 1, r.end());
return r;
}
case ast_func_translate:
{
string_t s = m_left->eval_string(c);
string_t from = m_right->eval_string(c);
string_t to = m_right->m_next->eval_string(c);
for (string_t::iterator it = s.begin(); it != s.end(); )
{
string_t::size_type pos = from.find(*it);
if (pos == string_t::npos)
++it;
else if (pos >= to.length())
it = s.erase(it);
else
*it++ = to[pos];
}
return s;
}
default:
{
switch (m_rettype)
{
case xpath_type_boolean:
return eval_boolean(c) ? PUGIXML_TEXT("true") : PUGIXML_TEXT("false");
case xpath_type_number:
return convert_number_to_string(eval_number(c));
case xpath_type_node_set:
{
xpath_node_set ns = eval_node_set(c);
return ns.empty() ? string_t() : string_value(ns.first());
}
default:
assert(!"Wrong expression for return type string");
return string_t();
}
}
}
}
xpath_node_set eval_node_set(const xpath_context& c)
{
switch (m_type)
{
case ast_op_union:
{
xpath_node_set ls = m_left->eval_node_set(c);
xpath_node_set rs = m_right->eval_node_set(c);
// we can optimize merging two sorted sets, but this is a very rare operation, so don't bother
ls.m_type = xpath_node_set::type_unsorted;
ls.append(rs.begin(), rs.end());
ls.remove_duplicates();
return ls;
}
case ast_filter:
case ast_filter_posinv:
{
xpath_node_set set = m_left->eval_node_set(c);
// either expression is a number or it contains position() call; sort by document order
if (m_type == ast_filter) set.sort();
apply_predicate(set, 0, m_right, c);
return set;
}
case ast_func_id:
return xpath_node_set();
case ast_step:
{
xpath_node_set ns;
switch (m_axis)
{
case axis_ancestor:
step_do(ns, c, axis_to_type<axis_ancestor>());
break;
case axis_ancestor_or_self:
step_do(ns, c, axis_to_type<axis_ancestor_or_self>());
break;
case axis_attribute:
step_do(ns, c, axis_to_type<axis_attribute>());
break;
case axis_child:
step_do(ns, c, axis_to_type<axis_child>());
break;
case axis_descendant:
step_do(ns, c, axis_to_type<axis_descendant>());
break;
case axis_descendant_or_self:
step_do(ns, c, axis_to_type<axis_descendant_or_self>());
break;
case axis_following:
step_do(ns, c, axis_to_type<axis_following>());
break;
case axis_following_sibling:
step_do(ns, c, axis_to_type<axis_following_sibling>());
break;
case axis_namespace:
step_do(ns, c, axis_to_type<axis_namespace>());
break;
case axis_parent:
step_do(ns, c, axis_to_type<axis_parent>());
break;
case axis_preceding:
step_do(ns, c, axis_to_type<axis_preceding>());
break;
case axis_preceding_sibling:
step_do(ns, c, axis_to_type<axis_preceding_sibling>());
break;
case axis_self:
step_do(ns, c, axis_to_type<axis_self>());
break;
}
ns.remove_duplicates();
return ns;
}
case ast_step_root:
{
xpath_node_set ns;
if (c.root)
{
ns.push_back(c.root);
apply_predicates(ns, 0, c);
}
return ns;
}
default:
assert(!"Wrong expression for return type node set");
return xpath_node_set();
}
}
bool is_posinv()
{
switch (m_type)
{
case ast_func_position:
return false;
case ast_string_constant:
case ast_number_constant:
// $$ case ast_variable:
return true;
case ast_step:
case ast_step_root:
return true;
case ast_predicate:
case ast_filter:
case ast_filter_posinv:
return true;
default:
if (m_left && !m_left->is_posinv()) return false;
for (xpath_ast_node* n = m_right; n; n = n->m_next)
if (!n->is_posinv()) return false;
return true;
}
}
xpath_value_type rettype() const
{
return static_cast<xpath_value_type>(m_rettype);
}
};
void* xpath_allocator::node()
{
return alloc(sizeof(xpath_ast_node));
}
class xpath_parser
{
private:
xpath_allocator& m_alloc;
xpath_lexer m_lexer;
xpath_parser(const xpath_parser&);
xpath_parser& operator=(const xpath_parser&);
xpath_ast_node* parse_function_helper(ast_type_t type0, ast_type_t type1, size_t argc, xpath_ast_node* args[2])
{
assert(argc <= 1);
if (argc == 1 && args[0]->rettype() != xpath_type_node_set) throw xpath_exception("Function has to be applied to node set");
return new (m_alloc.node()) xpath_ast_node(argc == 0 ? type0 : type1, xpath_type_string, args[0]);
}
xpath_ast_node* parse_function(const xpath_lexer_string& name, size_t argc, xpath_ast_node* args[2])
{
switch (name.begin[0])
{
case 'b':
if (name == PUGIXML_TEXT("boolean") && argc == 1)
return new (m_alloc.node()) xpath_ast_node(ast_func_boolean, xpath_type_boolean, args[0]);
break;
case 'c':
if (name == PUGIXML_TEXT("count") && argc == 1)
{
if (args[0]->rettype() != xpath_type_node_set) throw xpath_exception("count() has to be applied to node set");
return new (m_alloc.node()) xpath_ast_node(ast_func_count, xpath_type_number, args[0]);
}
else if (name == PUGIXML_TEXT("contains") && argc == 2)
return new (m_alloc.node()) xpath_ast_node(ast_func_contains, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("concat") && argc >= 2)
return new (m_alloc.node()) xpath_ast_node(ast_func_concat, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("ceiling") && argc == 1)
return new (m_alloc.node()) xpath_ast_node(ast_func_ceiling, xpath_type_number, args[0]);
break;
case 'f':
if (name == PUGIXML_TEXT("false") && argc == 0)
return new (m_alloc.node()) xpath_ast_node(ast_func_false, xpath_type_boolean);
else if (name == PUGIXML_TEXT("floor") && argc == 1)
return new (m_alloc.node()) xpath_ast_node(ast_func_floor, xpath_type_number, args[0]);
break;
case 'i':
if (name == PUGIXML_TEXT("id") && argc == 1)
return new (m_alloc.node()) xpath_ast_node(ast_func_id, xpath_type_node_set, args[0]);
break;
case 'l':
if (name == PUGIXML_TEXT("last") && argc == 0)
return new (m_alloc.node()) xpath_ast_node(ast_func_last, xpath_type_number);
else if (name == PUGIXML_TEXT("lang") && argc == 1)
return new (m_alloc.node()) xpath_ast_node(ast_func_lang, xpath_type_boolean, args[0]);
else if (name == PUGIXML_TEXT("local-name") && argc <= 1)
return parse_function_helper(ast_func_local_name_0, ast_func_local_name_1, argc, args);
break;
case 'n':
if (name == PUGIXML_TEXT("name") && argc <= 1)
return parse_function_helper(ast_func_name_0, ast_func_name_1, argc, args);
else if (name == PUGIXML_TEXT("namespace-uri") && argc <= 1)
return parse_function_helper(ast_func_namespace_uri_0, ast_func_namespace_uri_1, argc, args);
else if (name == PUGIXML_TEXT("normalize-space") && argc <= 1)
return new (m_alloc.node()) xpath_ast_node(argc == 0 ? ast_func_normalize_space_0 : ast_func_normalize_space_1, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("not") && argc == 1)
return new (m_alloc.node()) xpath_ast_node(ast_func_not, xpath_type_boolean, args[0]);
else if (name == PUGIXML_TEXT("number") && argc <= 1)
return new (m_alloc.node()) xpath_ast_node(argc == 0 ? ast_func_number_0 : ast_func_number_1, xpath_type_number, args[0]);
break;
case 'p':
if (name == PUGIXML_TEXT("position") && argc == 0)
return new (m_alloc.node()) xpath_ast_node(ast_func_position, xpath_type_number);
break;
case 'r':
if (name == PUGIXML_TEXT("round") && argc == 1)
return new (m_alloc.node()) xpath_ast_node(ast_func_round, xpath_type_number, args[0]);
break;
case 's':
if (name == PUGIXML_TEXT("string") && argc <= 1)
return new (m_alloc.node()) xpath_ast_node(argc == 0 ? ast_func_string_0 : ast_func_string_1, xpath_type_string, args[0]);
else if (name == PUGIXML_TEXT("string-length") && argc <= 1)
return new (m_alloc.node()) xpath_ast_node(argc == 0 ? ast_func_string_length_0 : ast_func_string_length_1, xpath_type_string, args[0]);
else if (name == PUGIXML_TEXT("starts-with") && argc == 2)
return new (m_alloc.node()) xpath_ast_node(ast_func_starts_with, xpath_type_boolean, args[0], args[1]);
else if (name == PUGIXML_TEXT("substring-before") && argc == 2)
return new (m_alloc.node()) xpath_ast_node(ast_func_substring_before, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("substring-after") && argc == 2)
return new (m_alloc.node()) xpath_ast_node(ast_func_substring_after, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("substring") && (argc == 2 || argc == 3))
return new (m_alloc.node()) xpath_ast_node(argc == 2 ? ast_func_substring_2 : ast_func_substring_3, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("sum") && argc == 1)
{
if (args[0]->rettype() != xpath_type_node_set) throw xpath_exception("sum() has to be applied to node set");
return new (m_alloc.node()) xpath_ast_node(ast_func_sum, xpath_type_number, args[0]);
}
break;
case 't':
if (name == PUGIXML_TEXT("translate") && argc == 3)
return new (m_alloc.node()) xpath_ast_node(ast_func_translate, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("true") && argc == 0)
return new (m_alloc.node()) xpath_ast_node(ast_func_true, xpath_type_boolean);
break;
}
throw xpath_exception("Unrecognized function or wrong parameter count");
#ifdef __DMC__
return 0; // Digital Mars C++
#endif
}
axis_t parse_axis_name(const xpath_lexer_string& name, bool& specified)
{
specified = true;
switch (name.begin[0])
{
case 'a':
if (name == PUGIXML_TEXT("ancestor"))
return axis_ancestor;
else if (name == PUGIXML_TEXT("ancestor-or-self"))
return axis_ancestor_or_self;
else if (name == PUGIXML_TEXT("attribute"))
return axis_attribute;
break;
case 'c':
if (name == PUGIXML_TEXT("child"))
return axis_child;
break;
case 'd':
if (name == PUGIXML_TEXT("descendant"))
return axis_descendant;
else if (name == PUGIXML_TEXT("descendant-or-self"))
return axis_descendant_or_self;
break;
case 'f':
if (name == PUGIXML_TEXT("following"))
return axis_following;
else if (name == PUGIXML_TEXT("following-sibling"))
return axis_following_sibling;
break;
case 'n':
if (name == PUGIXML_TEXT("namespace"))
return axis_namespace;
break;
case 'p':
if (name == PUGIXML_TEXT("parent"))
return axis_parent;
else if (name == PUGIXML_TEXT("preceding"))
return axis_preceding;
else if (name == PUGIXML_TEXT("preceding-sibling"))
return axis_preceding_sibling;
break;
case 's':
if (name == PUGIXML_TEXT("self"))
return axis_self;
break;
}
specified = false;
return axis_child;
}
nodetest_t parse_node_test_type(const xpath_lexer_string& name)
{
switch (name.begin[0])
{
case 'c':
if (name == PUGIXML_TEXT("comment"))
return nodetest_type_comment;
break;
case 'n':
if (name == PUGIXML_TEXT("node"))
return nodetest_type_node;
break;
case 'p':
if (name == PUGIXML_TEXT("processing-instruction"))
return nodetest_type_pi;
break;
case 't':
if (name == PUGIXML_TEXT("text"))
return nodetest_type_text;
break;
}
return nodetest_none;
}
// PrimaryExpr ::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall
xpath_ast_node* parse_primary_expression()
{
switch (m_lexer.current())
{
case lex_var_ref:
{
throw xpath_exception("Variables are not supported");
#ifdef __DMC__
return 0; // Digital Mars C++
#endif
}
case lex_open_brace:
{
m_lexer.next();
xpath_ast_node* n = parse_expression();
if (m_lexer.current() != lex_close_brace)
throw xpath_exception("Unmatched braces");
m_lexer.next();
return n;
}
case lex_quoted_string:
{
xpath_ast_node* n = new (m_alloc.node()) xpath_ast_node(ast_string_constant, xpath_type_string, m_lexer.contents(), m_alloc);
m_lexer.next();
return n;
}
case lex_number:
{
double value = convert_string_to_number(m_lexer.contents().begin, m_lexer.contents().end);
xpath_ast_node* n = new (m_alloc.node()) xpath_ast_node(ast_number_constant, xpath_type_number, value);
m_lexer.next();
return n;
}
case lex_string:
{
xpath_ast_node* args[2] = {0};
size_t argc = 0;
xpath_lexer_string function = m_lexer.contents();
m_lexer.next();
xpath_ast_node* last_arg = 0;
if (m_lexer.current() != lex_open_brace)
throw xpath_exception("Unrecognized function call");
m_lexer.next();
if (m_lexer.current() != lex_close_brace)
args[argc++] = parse_expression();
while (m_lexer.current() != lex_close_brace)
{
if (m_lexer.current() != lex_comma)
throw xpath_exception("No comma between function arguments");
m_lexer.next();
xpath_ast_node* n = parse_expression();
if (argc < 2) args[argc] = n;
else last_arg->set_next(n);
argc++;
last_arg = n;
}
m_lexer.next();
return parse_function(function, argc, args);
}
default:
throw xpath_exception("Unrecognizable primary expression");
#ifdef __DMC__
return 0; // Digital Mars C++
#endif
}
}
// FilterExpr ::= PrimaryExpr | FilterExpr Predicate
// Predicate ::= '[' PredicateExpr ']'
// PredicateExpr ::= Expr
xpath_ast_node* parse_filter_expression()
{
xpath_ast_node* n = parse_primary_expression();
while (m_lexer.current() == lex_open_square_brace)
{
m_lexer.next();
xpath_ast_node* expr = parse_expression();
if (n->rettype() != xpath_type_node_set) throw xpath_exception("Predicate has to be applied to node set");
bool posinv = expr->rettype() != xpath_type_number && expr->is_posinv();
n = new (m_alloc.node()) xpath_ast_node(posinv ? ast_filter_posinv : ast_filter, xpath_type_node_set, n, expr);
if (m_lexer.current() != lex_close_square_brace)
throw xpath_exception("Unmatched square brace");
m_lexer.next();
}
return n;
}
// Step ::= AxisSpecifier NodeTest Predicate* | AbbreviatedStep
// AxisSpecifier ::= AxisName '::' | '@'?
// NodeTest ::= NameTest | NodeType '(' ')' | 'processing-instruction' '(' Literal ')'
// NameTest ::= '*' | NCName ':' '*' | QName
// AbbreviatedStep ::= '.' | '..'
xpath_ast_node* parse_step(xpath_ast_node* set)
{
if (set && set->rettype() != xpath_type_node_set)
throw xpath_exception("Step has to be applied to node set");
bool axis_specified = false;
axis_t axis = axis_child; // implied child axis
if (m_lexer.current() == lex_axis_attribute)
{
axis = axis_attribute;
axis_specified = true;
m_lexer.next();
}
else if (m_lexer.current() == lex_dot)
{
m_lexer.next();
return new (m_alloc.node()) xpath_ast_node(ast_step, set, axis_self, nodetest_type_node, xpath_lexer_string(), m_alloc);
}
else if (m_lexer.current() == lex_double_dot)
{
m_lexer.next();
return new (m_alloc.node()) xpath_ast_node(ast_step, set, axis_parent, nodetest_type_node, xpath_lexer_string(), m_alloc);
}
nodetest_t nt_type = nodetest_none;
xpath_lexer_string nt_name;
if (m_lexer.current() == lex_string)
{
// node name test
nt_name = m_lexer.contents();
m_lexer.next();
// was it an axis name?
if (m_lexer.current() == lex_double_colon)
{
// parse axis name
if (axis_specified) throw xpath_exception("Two axis specifiers in one step");
axis = parse_axis_name(nt_name, axis_specified);
if (!axis_specified) throw xpath_exception("Unknown axis");
// read actual node test
m_lexer.next();
if (m_lexer.current() == lex_multiply)
{
nt_type = nodetest_all;
nt_name = xpath_lexer_string();
m_lexer.next();
}
else if (m_lexer.current() == lex_string)
{
nt_name = m_lexer.contents();
m_lexer.next();
}
else throw xpath_exception("Unrecognized node test");
}
if (nt_type == nodetest_none)
{
// node type test or processing-instruction
if (m_lexer.current() == lex_open_brace)
{
m_lexer.next();
if (m_lexer.current() == lex_close_brace)
{
m_lexer.next();
nt_type = parse_node_test_type(nt_name);
if (nt_type == nodetest_none) throw xpath_exception("Unrecognized node type");
nt_name = xpath_lexer_string();
}
else if (nt_name == PUGIXML_TEXT("processing-instruction"))
{
if (m_lexer.current() != lex_quoted_string)
throw xpath_exception("Only literals are allowed as arguments to processing-instruction()");
nt_type = nodetest_pi;
nt_name = m_lexer.contents();
m_lexer.next();
if (m_lexer.current() != lex_close_brace)
throw xpath_exception("Unmatched brace near processing-instruction()");
m_lexer.next();
}
else
throw xpath_exception("Unmatched brace near node type test");
}
// QName or NCName:*
else
{
const char_t* colon_pos = std::char_traits<char_t>::find(nt_name.begin, static_cast<size_t>(nt_name.end - nt_name.begin), ':');
if (colon_pos && colon_pos + 2 == nt_name.end && colon_pos[1] == '*') // NCName:*
{
nt_name.end--; // erase *
nt_type = nodetest_all_in_namespace;
}
else nt_type = nodetest_name;
}
}
}
else if (m_lexer.current() == lex_multiply)
{
nt_type = nodetest_all;
m_lexer.next();
}
else throw xpath_exception("Unrecognized node test");
xpath_ast_node* n = new (m_alloc.node()) xpath_ast_node(ast_step, set, axis, nt_type, nt_name, m_alloc);
xpath_ast_node* last = 0;
while (m_lexer.current() == lex_open_square_brace)
{
m_lexer.next();
xpath_ast_node* expr = parse_expression();
xpath_ast_node* pred = new (m_alloc.node()) xpath_ast_node(ast_predicate, xpath_type_node_set, expr);
if (m_lexer.current() != lex_close_square_brace)
throw xpath_exception("Unmatched square brace");
m_lexer.next();
if (last) last->set_next(pred);
else n->set_right(pred);
last = pred;
}
return n;
}
// RelativeLocationPath ::= Step | RelativeLocationPath '/' Step | RelativeLocationPath '//' Step
xpath_ast_node* parse_relative_location_path(xpath_ast_node* set)
{
xpath_ast_node* n = parse_step(set);
while (m_lexer.current() == lex_slash || m_lexer.current() == lex_double_slash)
{
lexeme_t l = m_lexer.current();
m_lexer.next();
if (l == lex_double_slash)
n = new (m_alloc.node()) xpath_ast_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, xpath_lexer_string(), m_alloc);
n = parse_step(n);
}
return n;
}
// LocationPath ::= RelativeLocationPath | AbsoluteLocationPath
// AbsoluteLocationPath ::= '/' RelativeLocationPath? | '//' RelativeLocationPath
xpath_ast_node* parse_location_path()
{
if (m_lexer.current() == lex_slash)
{
m_lexer.next();
xpath_ast_node* n = new (m_alloc.node()) xpath_ast_node(ast_step_root, xpath_type_node_set);
// relative location path can start from axis_attribute, dot, double_dot, multiply and string lexemes; any other lexeme means standalone root path
lexeme_t l = m_lexer.current();
if (l == lex_string || l == lex_axis_attribute || l == lex_dot || l == lex_double_dot || l == lex_multiply)
return parse_relative_location_path(n);
else
return n;
}
else if (m_lexer.current() == lex_double_slash)
{
m_lexer.next();
xpath_ast_node* n = new (m_alloc.node()) xpath_ast_node(ast_step_root, xpath_type_node_set);
n = new (m_alloc.node()) xpath_ast_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, xpath_lexer_string(), m_alloc);
return parse_relative_location_path(n);
}
else
{
return parse_relative_location_path(0);
}
}
// PathExpr ::= LocationPath
// | FilterExpr
// | FilterExpr '/' RelativeLocationPath
// | FilterExpr '//' RelativeLocationPath
xpath_ast_node* parse_path_expression()
{
// Clarification.
// PathExpr begins with either LocationPath or FilterExpr.
// FilterExpr begins with PrimaryExpr
// PrimaryExpr begins with '$' in case of it being a variable reference,
// '(' in case of it being an expression, string literal, number constant or
// function call.
if (m_lexer.current() == lex_var_ref || m_lexer.current() == lex_open_brace ||
m_lexer.current() == lex_quoted_string || m_lexer.current() == lex_number ||
m_lexer.current() == lex_string)
{
if (m_lexer.current() == lex_string)
{
// This is either a function call, or not - if not, we shall proceed with location path
const char_t* state = m_lexer.state();
while (IS_CHARTYPEX(*state, ctx_space)) ++state;
if (*state != '(') return parse_location_path();
// This looks like a function call; however this still can be a node-test. Check it.
if (parse_node_test_type(m_lexer.contents()) != nodetest_none) return parse_location_path();
}
xpath_ast_node* n = parse_filter_expression();
if (m_lexer.current() == lex_slash || m_lexer.current() == lex_double_slash)
{
lexeme_t l = m_lexer.current();
m_lexer.next();
if (l == lex_double_slash)
{
if (n->rettype() != xpath_type_node_set) throw xpath_exception("Step has to be applied to node set");
n = new (m_alloc.node()) xpath_ast_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, xpath_lexer_string(), m_alloc);
}
// select from location path
return parse_relative_location_path(n);
}
return n;
}
else return parse_location_path();
}
// UnionExpr ::= PathExpr | UnionExpr '|' PathExpr
xpath_ast_node* parse_union_expression()
{
xpath_ast_node* n = parse_path_expression();
while (m_lexer.current() == lex_union)
{
m_lexer.next();
xpath_ast_node* expr = parse_union_expression();
if (n->rettype() != xpath_type_node_set || expr->rettype() != xpath_type_node_set)
throw xpath_exception("Union operator has to be applied to node sets");
n = new (m_alloc.node()) xpath_ast_node(ast_op_union, xpath_type_node_set, n, expr);
}
return n;
}
// UnaryExpr ::= UnionExpr | '-' UnaryExpr
xpath_ast_node* parse_unary_expression()
{
if (m_lexer.current() == lex_minus)
{
m_lexer.next();
xpath_ast_node* expr = parse_unary_expression();
return new (m_alloc.node()) xpath_ast_node(ast_op_negate, xpath_type_number, expr);
}
else return parse_union_expression();
}
// MultiplicativeExpr ::= UnaryExpr
// | MultiplicativeExpr '*' UnaryExpr
// | MultiplicativeExpr 'div' UnaryExpr
// | MultiplicativeExpr 'mod' UnaryExpr
xpath_ast_node* parse_multiplicative_expression()
{
xpath_ast_node* n = parse_unary_expression();
while (m_lexer.current() == lex_multiply || (m_lexer.current() == lex_string &&
(m_lexer.contents() == PUGIXML_TEXT("mod") || m_lexer.contents() == PUGIXML_TEXT("div"))))
{
ast_type_t op = m_lexer.current() == lex_multiply ? ast_op_multiply :
m_lexer.contents().begin[0] == 'd' ? ast_op_divide : ast_op_mod;
m_lexer.next();
xpath_ast_node* expr = parse_unary_expression();
n = new (m_alloc.node()) xpath_ast_node(op, xpath_type_number, n, expr);
}
return n;
}
// AdditiveExpr ::= MultiplicativeExpr
// | AdditiveExpr '+' MultiplicativeExpr
// | AdditiveExpr '-' MultiplicativeExpr
xpath_ast_node* parse_additive_expression()
{
xpath_ast_node* n = parse_multiplicative_expression();
while (m_lexer.current() == lex_plus || m_lexer.current() == lex_minus)
{
lexeme_t l = m_lexer.current();
m_lexer.next();
xpath_ast_node* expr = parse_multiplicative_expression();
n = new (m_alloc.node()) xpath_ast_node(l == lex_plus ? ast_op_add : ast_op_subtract, xpath_type_number, n, expr);
}
return n;
}
// RelationalExpr ::= AdditiveExpr
// | RelationalExpr '<' AdditiveExpr
// | RelationalExpr '>' AdditiveExpr
// | RelationalExpr '<=' AdditiveExpr
// | RelationalExpr '>=' AdditiveExpr
xpath_ast_node* parse_relational_expression()
{
xpath_ast_node* n = parse_additive_expression();
while (m_lexer.current() == lex_less || m_lexer.current() == lex_less_or_equal ||
m_lexer.current() == lex_greater || m_lexer.current() == lex_greater_or_equal)
{
lexeme_t l = m_lexer.current();
m_lexer.next();
xpath_ast_node* expr = parse_additive_expression();
n = new (m_alloc.node()) xpath_ast_node(l == lex_less ? ast_op_less : l == lex_greater ? ast_op_greater :
l == lex_less_or_equal ? ast_op_less_or_equal : ast_op_greater_or_equal, xpath_type_boolean, n, expr);
}
return n;
}
// EqualityExpr ::= RelationalExpr
// | EqualityExpr '=' RelationalExpr
// | EqualityExpr '!=' RelationalExpr
xpath_ast_node* parse_equality_expression()
{
xpath_ast_node* n = parse_relational_expression();
while (m_lexer.current() == lex_equal || m_lexer.current() == lex_not_equal)
{
lexeme_t l = m_lexer.current();
m_lexer.next();
xpath_ast_node* expr = parse_relational_expression();
n = new (m_alloc.node()) xpath_ast_node(l == lex_equal ? ast_op_equal : ast_op_not_equal, xpath_type_boolean, n, expr);
}
return n;
}
// AndExpr ::= EqualityExpr | AndExpr 'and' EqualityExpr
xpath_ast_node* parse_and_expression()
{
xpath_ast_node* n = parse_equality_expression();
while (m_lexer.current() == lex_string && m_lexer.contents() == PUGIXML_TEXT("and"))
{
m_lexer.next();
xpath_ast_node* expr = parse_equality_expression();
n = new (m_alloc.node()) xpath_ast_node(ast_op_and, xpath_type_boolean, n, expr);
}
return n;
}
// OrExpr ::= AndExpr | OrExpr 'or' AndExpr
xpath_ast_node* parse_or_expression()
{
xpath_ast_node* n = parse_and_expression();
while (m_lexer.current() == lex_string && m_lexer.contents() == PUGIXML_TEXT("or"))
{
m_lexer.next();
xpath_ast_node* expr = parse_and_expression();
n = new (m_alloc.node()) xpath_ast_node(ast_op_or, xpath_type_boolean, n, expr);
}
return n;
}
// Expr ::= OrExpr
xpath_ast_node* parse_expression()
{
return parse_or_expression();
}
public:
explicit xpath_parser(const char_t* query, xpath_allocator& alloc): m_alloc(alloc), m_lexer(query)
{
}
xpath_ast_node* parse()
{
xpath_ast_node* result = parse_expression();
if (m_lexer.current() != lex_eof)
{
// there are still unparsed tokens left, error
throw xpath_exception("Incorrect query");
}
return result;
}
};
xpath_query::xpath_query(const char_t* query): m_alloc(0), m_root(0)
{
compile(query);
}
xpath_query::~xpath_query()
{
delete m_alloc;
}
void xpath_query::compile(const char_t* query)
{
delete m_alloc;
m_alloc = new xpath_allocator;
xpath_parser p(query, *m_alloc);
m_root = p.parse();
}
xpath_value_type xpath_query::return_type() const
{
if (!m_root) return xpath_type_none;
return m_root->rettype();
}
bool xpath_query::evaluate_boolean(const xml_node& n) const
{
if (!m_root) return false;
xpath_context c;
c.root = n.root();
c.n = n;
c.position = 1;
c.size = 1;
return m_root->eval_boolean(c);
}
double xpath_query::evaluate_number(const xml_node& n) const
{
if (!m_root) return gen_nan();
xpath_context c;
c.root = n.root();
c.n = n;
c.position = 1;
c.size = 1;
return m_root->eval_number(c);
}
string_t xpath_query::evaluate_string(const xml_node& n) const
{
if (!m_root) return string_t();
xpath_context c;
c.root = n.root();
c.n = n;
c.position = 1;
c.size = 1;
return m_root->eval_string(c);
}
xpath_node_set xpath_query::evaluate_node_set(const xml_node& n) const
{
if (!m_root) return xpath_node_set();
if (m_root->rettype() != xpath_type_node_set) throw xpath_exception("Expression does not evaluate to node set");
xpath_context c;
c.root = n.root();
c.n = n;
c.position = 1;
c.size = 1;
return m_root->eval_node_set(c);
}
xpath_node xml_node::select_single_node(const char_t* query) const
{
xpath_query q(query);
return select_single_node(q);
}
xpath_node xml_node::select_single_node(const xpath_query& query) const
{
xpath_node_set s = query.evaluate_node_set(*this);
return s.empty() ? xpath_node() : s.first();
}
xpath_node_set xml_node::select_nodes(const char_t* query) const
{
xpath_query q(query);
return select_nodes(q);
}
xpath_node_set xml_node::select_nodes(const xpath_query& query) const
{
return query.evaluate_node_set(*this);
}
}
#endif
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