Add (r)partition funcs to BLI_string, to get left-most/right-most first occurence of delimiters.

Inspired by Python (r)partition str functions. Also added some Gtest cases for those new funcs.

Reviewed by Campbell Barton, many thanks!

source/blender/blenfont/intern/blf_util.c

@@ -37,6 +37,7 @@
 
 #include "blf_internal.h"
 
+#include "BLI_utildefines.h"
 #include "BLI_string_utf8.h"
 
 unsigned int blf_next_p2(unsigned int x)

source/blender/blenlib/BLI_string.h

@@ -79,6 +79,10 @@ int BLI_str_rstrip_float_zero(char *str, const char pad) ATTR_NONNULL();
 int BLI_str_index_in_array_n(const char *__restrict str, const char **__restrict str_array, const int str_array_len) ATTR_NONNULL();
 int BLI_str_index_in_array(const char *__restrict str, const char **__restrict str_array) ATTR_NONNULL();
 
+size_t BLI_str_partition(const char *str, const unsigned int delim[], char **sep, char **suf) ATTR_NONNULL();
+size_t BLI_str_rpartition(const char *str, const unsigned int delim[], char **sep, char **suf) ATTR_NONNULL();
+size_t BLI_str_partition_ex(const char *str, const unsigned int delim[], char **sep, char **suf, const bool from_right) ATTR_NONNULL();
+
 #ifdef __cplusplus
 }
 #endif

source/blender/blenlib/BLI_string_utf8.h

@@ -66,6 +66,10 @@ int          BLI_wcswidth(const wchar_t *pwcs, size_t n) ATTR_NONNULL();
 int          BLI_str_utf8_char_width(const char *p) ATTR_NONNULL(); /* warning, can return -1 on bad chars */
 int          BLI_str_utf8_char_width_safe(const char *p) ATTR_NONNULL();
 
+size_t       BLI_str_partition_utf8(const char *str, const unsigned int delim[], char **sep, char **suf) ATTR_NONNULL();
+size_t       BLI_str_rpartition_utf8(const char *str, const unsigned int delim[], char **sep, char **suf) ATTR_NONNULL();
+size_t       BLI_str_partition_ex_utf8(const char *str, const unsigned int delim[], char **sep, char **suf, const bool from_right) ATTR_NONNULL();
+
 #define      BLI_UTF8_MAX 6        /* mem */
 #define      BLI_UTF8_WIDTH_MAX 2  /* columns */
 #define      BLI_UTF8_ERR ((unsigned int)-1)

source/blender/blenlib/intern/string.c

@@ -681,3 +681,63 @@ int BLI_str_index_in_array(const char *str, const char **str_array)
 	return -1;
 }
 
+/**
+ * Find the first char matching one of the chars in \a delim, from left.
+ *
+ * \param str The string to search within.
+ * \param delim The set of delimiters to search for, as unicode values.
+ * \param sep Return value, set to the first delimiter found (or NULL if none found).
+ * \param suf Return value, set to next char after the first delimiter found (or NULL if none found).
+ * \return The length of the prefix (i.e. *sep - str).
+ */
+size_t BLI_str_partition(const char *str, const unsigned int delim[], char **sep, char **suf)
+{
+	return BLI_str_partition_ex(str, delim, sep, suf, false);
+}
+
+/**
+ * Find the first char matching one of the chars in \a delim, from right.
+ *
+ * \param str The string to search within.
+ * \param delim The set of delimiters to search for, as unicode values.
+ * \param sep Return value, set to the first delimiter found (or NULL if none found).
+ * \param suf Return value, set to next char after the first delimiter found (or NULL if none found).
+ * \return The length of the prefix (i.e. *sep - str).
+ */
+size_t BLI_str_rpartition(const char *str, const unsigned int delim[], char **sep, char **suf)
+{
+	return BLI_str_partition_ex(str, delim, sep, suf, true);
+}
+
+/**
+ * Find the first char matching one of the chars in \a delim, either from left or right.
+ *
+ * \param str The string to search within.
+ * \param delim The set of delimiters to search for, as unicode values.
+ * \param sep Return value, set to the first delimiter found (or NULL if none found).
+ * \param suf Return value, set to next char after the first delimiter found (or NULL if none found).
+ * \param from_right If %true, search from the right of \a str, else, search from its left.
+ * \return The length of the prefix (i.e. *sep - str).
+ */
+size_t BLI_str_partition_ex(const char *str, const unsigned int delim[], char **sep, char **suf, const bool from_right)
+{
+	const unsigned int *d;
+	char *(*func)(const char *str, int c) = from_right ? strrchr : strchr;
+
+	*sep = *suf = NULL;
+
+	for (d = delim; *d != '\0'; ++d) {
+		char *tmp = func(str, (int)*d);
+
+		if (tmp && (from_right ? (*sep < tmp) : (!*sep || *sep > tmp))) {
+			*sep = tmp;
+		}
+	}
+
+	if (*sep) {
+		*suf = *sep + 1;
+		return (size_t)(*sep - str);
+	}
+
+	return strlen(str);
+}

source/blender/blenlib/intern/string_utf8.c

@@ -703,3 +703,49 @@ char *BLI_str_prev_char_utf8(const char *p)
 	}
 }
 /* end glib copy */
+
+size_t BLI_str_partition_utf8(const char *str, const unsigned int delim[], char **sep, char **suf)
+{
+	return BLI_str_partition_ex_utf8(str, delim, sep, suf, false);
+}
+
+size_t BLI_str_rpartition_utf8(const char *str, const unsigned int delim[], char **sep, char **suf)
+{
+	return BLI_str_partition_ex_utf8(str, delim, sep, suf, true);
+}
+
+size_t BLI_str_partition_ex_utf8(const char *str, const unsigned int delim[], char **sep, char **suf,
+                                 const bool from_right)
+{
+	const unsigned int *d;
+	const size_t str_len = strlen(str);
+	size_t index;
+
+	*suf = (char *)(str + str_len);
+
+	for (*sep = (char *)(from_right ? BLI_str_find_prev_char_utf8(str, str + str_len) : str), index = 0;
+	     *sep != NULL && **sep != '\0';
+	     *sep = (char *)(from_right ? (char *)BLI_str_find_prev_char_utf8(str, *sep) : str + index))
+	{
+		const unsigned int c = BLI_str_utf8_as_unicode_and_size(*sep, &index);
+
+		if (c == BLI_UTF8_ERR) {
+			*suf = *sep = NULL;
+			break;
+		}
+
+		for (d = delim; *d != '\0'; ++d) {
+			if (*d == c) {
+				/* *suf is already correct in case from_right is true. */
+				if (!from_right)
+					*suf = (char *)(str + index);
+				return (size_t)(*sep - str);
+			}
+		}
+
+		*suf = *sep;  /* Useful in 'from_right' case! */
+	}
+
+	*suf = *sep = NULL;
+	return str_len;
+}

source/blender/blenlib/intern/timecode.c

@@ -33,6 +33,7 @@
 #include <stdio.h>
 
 
+#include "BLI_utildefines.h"
 #include "BLI_string.h"
 #include "BLI_math.h"
 

source/blender/imbuf/intern/metadata.c

@@ -33,6 +33,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "BLI_utildefines.h"
 #include "BLI_string.h"
 
 #include "MEM_guardedalloc.h"

tests/gtests/blenlib/BLI_string_test.cc

@@ -0,0 +1,269 @@
+/* Apache License, Version 2.0 */
+
+#include "testing/testing.h"
+
+extern "C" {
+#include "BLI_utildefines.h"
+#include "BLI_string.h"
+#include "BLI_string_utf8.h"
+}
+
+/* -------------------------------------------------------------------- */
+/* stubs */
+
+extern "C" {
+
+int mk_wcwidth(wchar_t ucs);
+int mk_wcswidth(const wchar_t *pwcs, size_t n);
+
+int mk_wcwidth(wchar_t ucs)
+{
+	return 0;
+}
+
+int mk_wcswidth(const wchar_t *pwcs, size_t n)
+{
+	return 0;
+}
+
+}
+
+
+/* -------------------------------------------------------------------- */
+/* tests */
+
+/* BLI_str_partition */
+TEST(string, StrPartition)
+{
+	const unsigned int delim[] = {'-', '.', '_', 0x00F1 /* n tilde */, 0x262F /* ying-yang */, '\0'};
+	char *sep, *suf;
+	size_t pre_ln;
+
+	{
+		const char *str = "mat.e-r_ial";
+
+		/* "mat.e-r_ial" -> "mat", '.', "e-r_ial", 3 */
+		pre_ln = BLI_str_partition(str, delim, &sep, &suf);
+		EXPECT_EQ(3, pre_ln);
+		EXPECT_EQ(&str[3], sep);
+		EXPECT_STREQ("e-r_ial", suf);
+	}
+
+	/* Corner cases. */
+	{
+		const char *str = ".mate-rial--";
+
+		/* ".mate-rial--" -> "", '.', "mate-rial--", 0 */
+		pre_ln = BLI_str_partition(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(&str[0], sep);
+		EXPECT_STREQ("mate-rial--", suf);
+	}
+
+	{
+		const char *str = ".__.--_";
+
+		/* ".__.--_" -> "", '.', "__.--_", 0 */
+		pre_ln = BLI_str_partition(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(&str[0], sep);
+		EXPECT_STREQ("__.--_", suf);
+	}
+
+	{
+		const char *str = "";
+
+		/* "" -> "", NULL, NULL, 0 */
+		pre_ln = BLI_str_partition(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+
+	{
+		const char *str = "material";
+
+		/* "material" -> "material", NULL, NULL, 8 */
+		pre_ln = BLI_str_partition(str, delim, &sep, &suf);
+		EXPECT_EQ(8, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+}
+
+/* BLI_str_rpartition */
+TEST(string, StrRPartition)
+{
+	const unsigned int delim[] = {'-', '.', '_', 0x00F1 /* n tilde */, 0x262F /* ying-yang */, '\0'};
+	char *sep, *suf;
+	size_t pre_ln;
+
+	{
+		const char *str = "mat.e-r_ial";
+
+		/* "mat.e-r_ial" -> "mat.e-r", '_', "ial", 7 */
+		pre_ln = BLI_str_rpartition(str, delim, &sep, &suf);
+		EXPECT_EQ(7, pre_ln);
+		EXPECT_EQ(&str[7], sep);
+		EXPECT_STREQ("ial", suf);
+	}
+
+	/* Corner cases. */
+	{
+		const char *str = ".mate-rial--";
+
+		/* ".mate-rial--" -> ".mate-rial-", '-', "", 11 */
+		pre_ln = BLI_str_rpartition(str, delim, &sep, &suf);
+		EXPECT_EQ(11, pre_ln);
+		EXPECT_EQ(&str[11], sep);
+		EXPECT_STREQ("", suf);
+	}
+
+	{
+		const char *str = ".__.--_";
+
+		/* ".__.--_" -> ".__.--", '_', "", 6 */
+		pre_ln = BLI_str_rpartition(str, delim, &sep, &suf);
+		EXPECT_EQ(6, pre_ln);
+		EXPECT_EQ(&str[6], sep);
+		EXPECT_STREQ("", suf);
+	}
+
+	{
+		const char *str = "";
+
+		/* "" -> "", NULL, NULL, 0 */
+		pre_ln = BLI_str_rpartition(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+
+	{
+		const char *str = "material";
+
+		/* "material" -> "material", NULL, NULL, 8 */
+		pre_ln = BLI_str_rpartition(str, delim, &sep, &suf);
+		EXPECT_EQ(8, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+}
+
+/* BLI_str_partition_utf8 */
+TEST(string, StrPartitionUtf8)
+{
+	const unsigned int delim[] = {'-', '.', '_', 0x00F1 /* n tilde */, 0x262F /* ying-yang */, '\0'};
+	char *sep, *suf;
+	size_t pre_ln;
+
+	{
+		const char *str = "ma\xc3\xb1te-r\xe2\x98\xafial";
+
+		/* "ma\xc3\xb1te-r\xe2\x98\xafial" -> "ma", '\xc3\xb1', "te-r\xe2\x98\xafial", 2 */
+		pre_ln = BLI_str_partition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(2, pre_ln);
+		EXPECT_EQ(&str[2], sep);
+		EXPECT_STREQ("te-r\xe2\x98\xafial", suf);
+	}
+
+	/* Corner cases. */
+	{
+		const char *str = "\xe2\x98\xafmate-rial-\xc3\xb1";
+
+		/* "\xe2\x98\xafmate-rial-\xc3\xb1" -> "", '\xe2\x98\xaf', "mate-rial-\xc3\xb1", 0 */
+		pre_ln = BLI_str_partition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(&str[0], sep);
+		EXPECT_STREQ("mate-rial-\xc3\xb1", suf);
+	}
+
+	{
+		const char *str = "\xe2\x98\xaf.\xc3\xb1_.--\xc3\xb1";
+
+		/* "\xe2\x98\xaf.\xc3\xb1_.--\xc3\xb1" -> "", '\xe2\x98\xaf', ".\xc3\xb1_.--\xc3\xb1", 0 */
+		pre_ln = BLI_str_partition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(&str[0], sep);
+		EXPECT_STREQ(".\xc3\xb1_.--\xc3\xb1", suf);
+	}
+
+	{
+		const char *str = "";
+
+		/* "" -> "", NULL, NULL, 0 */
+		pre_ln = BLI_str_partition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+
+	{
+		const char *str = "material";
+
+		/* "material" -> "material", NULL, NULL, 8 */
+		pre_ln = BLI_str_partition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(8, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+}
+
+/* BLI_str_rpartition_utf8 */
+TEST(string, StrRPartitionUtf8)
+{
+	const unsigned int delim[] = {'-', '.', '_', 0x00F1 /* n tilde */, 0x262F /* ying-yang */, '\0'};
+	char *sep, *suf;
+	size_t pre_ln;
+
+	{
+		const char *str = "ma\xc3\xb1te-r\xe2\x98\xafial";
+
+		/* "ma\xc3\xb1te-r\xe2\x98\xafial" -> "mat\xc3\xb1te-r", '\xe2\x98\xaf', "ial", 8 */
+		pre_ln = BLI_str_rpartition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(8, pre_ln);
+		EXPECT_EQ(&str[8], sep);
+		EXPECT_STREQ("ial", suf);
+	}
+
+	/* Corner cases. */
+	{
+		const char *str = "\xe2\x98\xafmate-rial-\xc3\xb1";
+
+		/* "\xe2\x98\xafmate-rial-\xc3\xb1" -> "\xe2\x98\xafmate-rial-", '\xc3\xb1', "", 13 */
+		pre_ln = BLI_str_rpartition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(13, pre_ln);
+		EXPECT_EQ(&str[13], sep);
+		EXPECT_STREQ("", suf);
+	}
+
+	{
+		const char *str = "\xe2\x98\xaf.\xc3\xb1_.--\xc3\xb1";
+
+		/* "\xe2\x98\xaf.\xc3\xb1_.--\xc3\xb1" -> "\xe2\x98\xaf.\xc3\xb1_.--", '\xc3\xb1', "", 10 */
+		pre_ln = BLI_str_rpartition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(10, pre_ln);
+		EXPECT_EQ(&str[10], sep);
+		EXPECT_STREQ("", suf);
+	}
+
+	{
+		const char *str = "";
+
+		/* "" -> "", NULL, NULL, 0 */
+		pre_ln = BLI_str_rpartition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(0, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+
+	{
+		const char *str = "material";
+
+		/* "material" -> "material", NULL, NULL, 8 */
+		pre_ln = BLI_str_rpartition_utf8(str, delim, &sep, &suf);
+		EXPECT_EQ(8, pre_ln);
+		EXPECT_EQ(NULL, sep);
+		EXPECT_EQ(NULL, suf);
+	}
+}

tests/gtests/blenlib/CMakeLists.txt

@@ -37,4 +37,5 @@ set(CMAKE_EXE_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG} ${PLATFORM_LIN
 BLENDER_TEST(BLI_stack "bf_blenlib")
 BLENDER_TEST(BLI_math_color "bf_blenlib")
 BLENDER_TEST(BLI_math_geom "bf_blenlib")
+BLENDER_TEST(BLI_string "bf_blenlib")
 BLENDER_TEST(BLI_path_util "bf_blenlib;extern_wcwidth;${ZLIB_LIBRARIES}")