Add {start,end}with_lower methods to StringRef.

startswith_lower is ocassionally useful and I think worth adding.
endwith_lower is added for completeness.

Differential Revision: http://llvm-reviews.chandlerc.com/D2041

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193706 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rui Ueyama 2013-10-30 18:32:26 +00:00
parent 3f04b50686
commit f34c3ca304
3 changed files with 53 additions and 5 deletions

View File

@ -210,12 +210,18 @@ namespace llvm {
compareMemory(Data, Prefix.Data, Prefix.Length) == 0;
}
/// Check if this string starts with the given \p Prefix, ignoring case.
bool startswith_lower(StringRef Prefix) const;
/// Check if this string ends with the given \p Suffix.
bool endswith(StringRef Suffix) const {
return Length >= Suffix.Length &&
compareMemory(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
}
/// Check if this string ends with the given \p Suffix, ignoring case.
bool endswith_lower(StringRef Suffix) const;
/// @}
/// @name String Searching
/// @{

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@ -37,20 +37,39 @@ static bool ascii_isdigit(char x) {
return x >= '0' && x <= '9';
}
/// compare_lower - Compare strings, ignoring case.
int StringRef::compare_lower(StringRef RHS) const {
for (size_t I = 0, E = min(Length, RHS.Length); I != E; ++I) {
unsigned char LHC = ascii_tolower(Data[I]);
unsigned char RHC = ascii_tolower(RHS.Data[I]);
// strncasecmp() is not available on non-POSIX systems, so define an
// alternative function here.
static int ascii_strncasecmp(const char *LHS, const char *RHS, size_t Length) {
for (size_t I = 0; I < Length; ++I) {
unsigned char LHC = ascii_tolower(LHS[I]);
unsigned char RHC = ascii_tolower(RHS[I]);
if (LHC != RHC)
return LHC < RHC ? -1 : 1;
}
return 0;
}
/// compare_lower - Compare strings, ignoring case.
int StringRef::compare_lower(StringRef RHS) const {
if (int Res = ascii_strncasecmp(Data, RHS.Data, min(Length, RHS.Length)))
return Res;
if (Length == RHS.Length)
return 0;
return Length < RHS.Length ? -1 : 1;
}
/// Check if this string starts with the given \p Prefix, ignoring case.
bool StringRef::startswith_lower(StringRef Prefix) const {
return Length >= Prefix.Length &&
ascii_strncasecmp(Data, Prefix.Data, Prefix.Length) == 0;
}
/// Check if this string ends with the given \p Suffix, ignoring case.
bool StringRef::endswith_lower(StringRef Suffix) const {
return Length >= Suffix.Length &&
ascii_strncasecmp(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
}
/// compare_numeric - Compare strings, handle embedded numbers.
int StringRef::compare_numeric(StringRef RHS) const {
for (size_t I = 0, E = min(Length, RHS.Length); I != E; ++I) {

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@ -61,6 +61,9 @@ TEST(StringRefTest, StringOps) {
EXPECT_EQ( 0, StringRef("AaB").compare_lower("aab"));
EXPECT_EQ( 1, StringRef("AaB").compare_lower("AAA"));
EXPECT_EQ(-1, StringRef("AaB").compare_lower("aaBb"));
EXPECT_EQ(-1, StringRef("AaB").compare_lower("bb"));
EXPECT_EQ( 1, StringRef("aaBb").compare_lower("AaB"));
EXPECT_EQ( 1, StringRef("bb").compare_lower("AaB"));
EXPECT_EQ( 1, StringRef("AaB").compare_lower("aA"));
EXPECT_EQ( 1, StringRef("\xFF").compare_lower("\1"));
@ -254,6 +257,16 @@ TEST(StringRefTest, StartsWith) {
EXPECT_FALSE(Str.startswith("hi"));
}
TEST(StringRefTest, StartsWithLower) {
StringRef Str("heLLo");
EXPECT_TRUE(Str.startswith_lower(""));
EXPECT_TRUE(Str.startswith_lower("he"));
EXPECT_TRUE(Str.startswith_lower("hell"));
EXPECT_TRUE(Str.startswith_lower("HELlo"));
EXPECT_FALSE(Str.startswith_lower("helloworld"));
EXPECT_FALSE(Str.startswith_lower("hi"));
}
TEST(StringRefTest, EndsWith) {
StringRef Str("hello");
EXPECT_TRUE(Str.endswith(""));
@ -263,6 +276,16 @@ TEST(StringRefTest, EndsWith) {
EXPECT_FALSE(Str.endswith("so"));
}
TEST(StringRefTest, EndsWithLower) {
StringRef Str("heLLo");
EXPECT_TRUE(Str.endswith_lower(""));
EXPECT_TRUE(Str.endswith_lower("lo"));
EXPECT_TRUE(Str.endswith_lower("LO"));
EXPECT_TRUE(Str.endswith_lower("ELlo"));
EXPECT_FALSE(Str.endswith_lower("helloworld"));
EXPECT_FALSE(Str.endswith_lower("hi"));
}
TEST(StringRefTest, Find) {
StringRef Str("hello");
EXPECT_EQ(2U, Str.find('l'));