Add ctl string find_first_of and find_last_of

ctl/string_view.cc

@@ -108,4 +108,66 @@ string_view::starts_with(const string_view s) const noexcept
     return !memcmp(p, s.p, s.n);
 }
 
+size_t
+string_view::find_last_of(char c, size_t pos) const noexcept
+{
+    const char* b = data();
+    size_t n = size();
+    if (pos > n)
+        pos = n;
+    const char* p = (const char*)memrchr(b, c, pos);
+    return p ? p - b : npos;
+}
+
+size_t
+string_view::find_last_of(ctl::string_view set, size_t pos) const noexcept
+{
+    if (empty() || set.empty())
+        return npos;
+    bool lut[256] = {};
+    for (char c : set)
+        lut[c & 255] = true;
+    const char* b = data();
+    size_t last = size() - 1;
+    if (pos > last)
+        pos = last;
+    for (;;) {
+        if (lut[b[pos] & 255])
+            return pos;
+        if (!pos)
+            return npos;
+        --pos;
+    }
+}
+
+size_t
+string_view::find_first_of(char c, size_t pos) const noexcept
+{
+    size_t n = size();
+    if (pos >= n)
+        return npos;
+    const char* b = data();
+    const char* p = (const char*)memchr(b + pos, c, n - pos);
+    return p ? p - b : npos;
+}
+
+size_t
+string_view::find_first_of(ctl::string_view set, size_t pos) const noexcept
+{
+    if (set.empty())
+        return npos;
+    bool lut[256] = {};
+    for (char c : set)
+        lut[c & 255] = true;
+    const char* b = data();
+    size_t n = size();
+    for (;;) {
+        if (pos >= n)
+            return npos;
+        if (lut[b[pos] & 255])
+            return pos;
+        ++pos;
+    }
+}
+
 } // namespace ctl