raze-gles/tools/re2c/src/parse/unescape.cc
Christoph Oelckers 8c95516224 - added compile tools from GZDoom repo:
- updaterevision for automated revision string generation
- re2c as a prerequisite to use sc_man in the future
- zipdir to automatically generate an engine resource file.
2019-09-22 08:52:30 +02:00

60 lines
1 KiB
C++

#include "src/parse/unescape.h"
namespace re2c {
// expected characters: [0-9a-zA-Z]
static inline uint32_t hex_digit (const char c)
{
switch (c)
{
case '0': return 0;
case '1': return 1;
case '2': return 2;
case '3': return 3;
case '4': return 4;
case '5': return 5;
case '6': return 6;
case '7': return 7;
case '8': return 8;
case '9': return 9;
case 'a':
case 'A': return 0xA;
case 'b':
case 'B': return 0xB;
case 'c':
case 'C': return 0xC;
case 'd':
case 'D': return 0xD;
case 'e':
case 'E': return 0xE;
case 'f':
case 'F': return 0xF;
default: return ~0u; // unexpected
}
}
// expected string format: "\" [xXuU] [0-9a-zA-Z]*
uint32_t unesc_hex (const char * s, const char * s_end)
{
uint32_t n = 0;
for (s += 2; s != s_end; ++s)
{
n <<= 4;
n += hex_digit (*s);
}
return n;
}
// expected string format: "\" [0-7]*
uint32_t unesc_oct (const char * s, const char * s_end)
{
uint32_t n = 0;
for (++s; s != s_end; ++s)
{
n <<= 3;
n += static_cast<uint8_t> (*s - '0');
}
return n;
}
} // namespace re2c