bsnes/nall/string/eval/literal.hpp

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#ifdef NALL_STRING_INTERNAL_HPP
namespace nall {
namespace Eval {
inline bool isLiteral(const char*& s) {
char n = s[0];
return (n >= 'A' && n <= 'Z')
|| (n >= 'a' && n <= 'z')
|| (n >= '0' && n <= '9')
|| (n == '%' || n == '$' || n == '_' || n == '.')
|| (n == '\'' || n == '\"');
}
inline string literalNumber(const char*& s) {
const char* p = s;
//binary
if(p[0] == '%' || (p[0] == '0' && p[1] == 'b')) {
unsigned prefix = 1 + (p[0] == '0');
p += prefix;
while(p[0] == '\'' || p[0] == '0' || p[0] == '1') p++;
if(p - s <= prefix) throw "invalid binary literal";
string result = substr(s, 0, p - s);
s = p;
return result;
}
//octal
if(p[0] == '0' && p[1] == 'o') {
unsigned prefix = 1 + (p[0] == '0');
p += prefix;
while(p[0] == '\'' || (p[0] >= '0' && p[0] <= '7')) p++;
if(p - s <= prefix) throw "invalid octal literal";
string result = substr(s, 0, p - s);
s = p;
return result;
}
//hex
if(p[0] == '$' || (p[0] == '0' && p[1] == 'x')) {
unsigned prefix = 1 + (p[0] == '0');
p += prefix;
while(p[0] == '\'' || (p[0] >= '0' && p[0] <= '9') || (p[0] >= 'A' && p[0] <= 'F') || (p[0] >= 'a' && p[0] <= 'f')) p++;
if(p - s <= prefix) throw "invalid hex literal";
string result = substr(s, 0, p - s);
s = p;
return result;
}
//decimal
while(p[0] == '\'' || (p[0] >= '0' && p[0] <= '9')) p++;
if(p[0] != '.') {
string result = substr(s, 0, p - s);
s = p;
return result;
}
//floating-point
p++;
while(p[0] == '\'' || (p[0] >= '0' && p[0] <= '9')) p++;
string result = substr(s, 0, p - s);
s = p;
return result;
}
inline string literalString(const char*& s) {
const char* p = s;
char escape = *p++;
while(p[0] && p[0] != escape) p++;
if(*p++ != escape) throw "unclosed string literal";
string result = substr(s, 0, p - s);
s = p;
return result;
}
inline string literalVariable(const char*& s) {
const char* p = s;
while(p[0] == '_' || p[0] == '.' || (p[0] >= 'A' && p[0] <= 'Z') || (p[0] >= 'a' && p[0] <= 'z') || (p[0] >= '0' && p[0] <= '9')) p++;
string result = substr(s, 0, p - s);
s = p;
return result;
}
inline string literal(const char*& s) {
const char* p = s;
if(p[0] >= '0' && p[0] <= '9') return literalNumber(s);
if(p[0] == '%' || p[0] == '$') return literalNumber(s);
if(p[0] == '\'' || p[0] == '\"') return literalString(s);
if(p[0] == '_' || p[0] == '.' || (p[0] >= 'A' && p[0] <= 'Z') || (p[0] >= 'a' && p[0] <= 'z')) return literalVariable(s);
throw "invalid literal";
}
}
}
#endif