mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-01 16:33:37 +01:00
127 lines
3.8 KiB
C++
127 lines
3.8 KiB
C++
//===--- StringSwitch.h - Switch-on-literal-string Construct --------------===/
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//===----------------------------------------------------------------------===/
|
|
//
|
|
// This file implements the StringSwitch template, which mimics a switch()
|
|
// statement whose cases are string literals.
|
|
//
|
|
//===----------------------------------------------------------------------===/
|
|
#ifndef LLVM_ADT_STRINGSWITCH_H
|
|
#define LLVM_ADT_STRINGSWITCH_H
|
|
|
|
#include "llvm/ADT/StringRef.h"
|
|
#include <cassert>
|
|
#include <cstring>
|
|
|
|
namespace llvm {
|
|
|
|
/// \brief A switch()-like statement whose cases are string literals.
|
|
///
|
|
/// The StringSwitch class is a simple form of a switch() statement that
|
|
/// determines whether the given string matches one of the given string
|
|
/// literals. The template type parameter \p T is the type of the value that
|
|
/// will be returned from the string-switch expression. For example,
|
|
/// the following code switches on the name of a color in \c argv[i]:
|
|
///
|
|
/// \code
|
|
/// Color color = StringSwitch<Color>(argv[i])
|
|
/// .Case("red", Red)
|
|
/// .Case("orange", Orange)
|
|
/// .Case("yellow", Yellow)
|
|
/// .Case("green", Green)
|
|
/// .Case("blue", Blue)
|
|
/// .Case("indigo", Indigo)
|
|
/// .Cases("violet", "purple", Violet)
|
|
/// .Default(UnknownColor);
|
|
/// \endcode
|
|
template<typename T, typename R = T>
|
|
class StringSwitch {
|
|
/// \brief The string we are matching.
|
|
StringRef Str;
|
|
|
|
/// \brief The pointer to the result of this switch statement, once known,
|
|
/// null before that.
|
|
const T *Result;
|
|
|
|
public:
|
|
explicit StringSwitch(StringRef Str)
|
|
: Str(Str), Result(0) { }
|
|
|
|
template<unsigned N>
|
|
StringSwitch& Case(const char (&S)[N], const T& Value) {
|
|
if (!Result && N-1 == Str.size() &&
|
|
(std::memcmp(S, Str.data(), N-1) == 0)) {
|
|
Result = &Value;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
template<unsigned N>
|
|
StringSwitch& EndsWith(const char (&S)[N], const T &Value) {
|
|
if (!Result && Str.size() >= N-1 &&
|
|
std::memcmp(S, Str.data() + Str.size() + 1 - N, N-1) == 0) {
|
|
Result = &Value;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
template<unsigned N>
|
|
StringSwitch& StartsWith(const char (&S)[N], const T &Value) {
|
|
if (!Result && Str.size() >= N-1 &&
|
|
std::memcmp(S, Str.data(), N-1) == 0) {
|
|
Result = &Value;
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
template<unsigned N0, unsigned N1>
|
|
StringSwitch& Cases(const char (&S0)[N0], const char (&S1)[N1],
|
|
const T& Value) {
|
|
return Case(S0, Value).Case(S1, Value);
|
|
}
|
|
|
|
template<unsigned N0, unsigned N1, unsigned N2>
|
|
StringSwitch& Cases(const char (&S0)[N0], const char (&S1)[N1],
|
|
const char (&S2)[N2], const T& Value) {
|
|
return Case(S0, Value).Case(S1, Value).Case(S2, Value);
|
|
}
|
|
|
|
template<unsigned N0, unsigned N1, unsigned N2, unsigned N3>
|
|
StringSwitch& Cases(const char (&S0)[N0], const char (&S1)[N1],
|
|
const char (&S2)[N2], const char (&S3)[N3],
|
|
const T& Value) {
|
|
return Case(S0, Value).Case(S1, Value).Case(S2, Value).Case(S3, Value);
|
|
}
|
|
|
|
template<unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4>
|
|
StringSwitch& Cases(const char (&S0)[N0], const char (&S1)[N1],
|
|
const char (&S2)[N2], const char (&S3)[N3],
|
|
const char (&S4)[N4], const T& Value) {
|
|
return Case(S0, Value).Case(S1, Value).Case(S2, Value).Case(S3, Value)
|
|
.Case(S4, Value);
|
|
}
|
|
|
|
R Default(const T& Value) const {
|
|
if (Result)
|
|
return *Result;
|
|
|
|
return Value;
|
|
}
|
|
|
|
operator R() const {
|
|
assert(Result && "Fell off the end of a string-switch");
|
|
return *Result;
|
|
}
|
|
};
|
|
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_ADT_STRINGSWITCH_H
|