1 files changed, 85 insertions, 0 deletions
diff --git a/examples/dte/regexp.h b/examples/dte/regexp.h
new file mode 100644
index 0000000..50fdabb
--- /dev/null
+++ b/examples/dte/regexp.h
@@ -0,0 +1,85 @@
+#ifndef REGEXP_H
+#define REGEXP_H
+
+#include <regex.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include "util/macros.h"
+
+enum {
+#ifdef REG_ENHANCED
+    // The REG_ENHANCED flag enables various extensions on macOS
+    // (see "enhanced features" in re_format(7)). Most of these
+    // extensions are enabled by default on Linux (in both glibc
+    // and musl) without the need for any extra flags.
+    DEFAULT_REGEX_FLAGS = REG_EXTENDED | REG_ENHANCED,
+#else
+    // POSIX Extended Regular Expressions (ERE) are used almost
+    // everywhere in this codebase, except where Basic Regular
+    // Expressions (BRE) are explicitly called for (most notably
+    // in search_tag(), which is used for ctags patterns).
+    DEFAULT_REGEX_FLAGS = REG_EXTENDED,
+#endif
+};
+
+typedef struct {
+    regex_t re;
+    char str[];
+} CachedRegexp;
+
+typedef struct {
+    char *str;
+    regex_t re;
+} InternedRegexp;
+
+// Platform-specific patterns for matching word boundaries, as detected
+// and initialized by regexp_init_word_boundary_tokens()
+typedef struct {
+    char start[8];
+    char end[8];
+} RegexpWordBoundaryTokens;
+
+bool regexp_compile_internal(regex_t *re, const char *pattern, int flags) WARN_UNUSED_RESULT;
+
+WARN_UNUSED_RESULT
+static inline bool regexp_compile(regex_t *re, const char *pattern, int flags)
+{
+    return regexp_compile_internal(re, pattern, flags | DEFAULT_REGEX_FLAGS);
+}
+
+WARN_UNUSED_RESULT
+static inline bool regexp_compile_basic(regex_t *re, const char *pattern, int flags)
+{
+    return regexp_compile_internal(re, pattern, flags);
+}
+
+WARN_UNUSED_RESULT
+static inline bool regexp_is_valid(const char *pattern, int flags)
+{
+    regex_t re;
+    if (!regexp_compile(&re, pattern, flags | REG_NOSUB)) {
+        return false;
+    }
+    regfree(&re);
+    return true;
+}
+
+void regexp_compile_or_fatal_error(regex_t *re, const char *pattern, int flags);
+bool regexp_init_word_boundary_tokens(RegexpWordBoundaryTokens *rwbt);
+bool regexp_error_msg(const regex_t *re, const char *pattern, int err);
+void free_cached_regexp(CachedRegexp *cr);
+
+const InternedRegexp *regexp_intern(const char *pattern);
+bool regexp_is_interned(const char *pattern);
+void free_interned_regexps(void);
+
+bool regexp_exec (
+    const regex_t *re,
+    const char *buf,
+    size_t size,
+    size_t nmatch,
+    regmatch_t *pmatch,
+    int flags
+) WARN_UNUSED_RESULT;
+
+#endif