AK: Add SplitBehavior::KeepTrailingSeparator with tests

luteresa · Oct 24, 2022 · 7c33f8f · 7c33f8f
1 parent 3e8b5ac
commit 7c33f8f
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Showing 5 changed files with 26 additions and 6 deletions.
diff --git a/AK/String.cpp b/AK/String.cpp
@@ -110,12 +110,13 @@ Vector<String> String::split_limit(char separator, size_t limit, SplitBehavior s
  Vector<String> v;
  size_t substart = 0;
  bool keep_empty = has_flag(split_behavior, SplitBehavior::KeepEmpty);
+ bool keep_separator = has_flag(split_behavior, SplitBehavior::KeepTrailingSeparator);
  for (size_t i = 0; i < length() && (v.size() + 1) != limit; ++i) {
  char ch = characters()[i];
  if (ch == separator) {
  size_t sublen = i - substart;
  if (sublen != 0 || keep_empty)
- v.append(substring(substart, sublen));
+ v.append(substring(substart, keep_separator ? sublen + 1 : sublen));
  substart = i + 1;
  }
  }
@@ -133,12 +134,13 @@ Vector<StringView> String::split_view(Function<bool(char)> separator, SplitBehav
  Vector<StringView> v;
  size_t substart = 0;
  bool keep_empty = has_flag(split_behavior, SplitBehavior::KeepEmpty);
+ bool keep_separator = has_flag(split_behavior, SplitBehavior::KeepTrailingSeparator);
  for (size_t i = 0; i < length(); ++i) {
  char ch = characters()[i];
  if (separator(ch)) {
  size_t sublen = i - substart;
  if (sublen != 0 || keep_empty)
- v.append(substring_view(substart, sublen));
+ v.append(substring_view(substart, keep_separator ? sublen + 1 : sublen));
  substart = i + 1;
  }
  }

diff --git a/AK/StringUtils.h b/AK/StringUtils.h
@@ -40,10 +40,17 @@ enum class TrimWhitespace {
 };
 
 enum class SplitBehavior : unsigned {
+ // Neither keep empty substrings nor keep the trailing separator.
+ // This is the default behavior if unspecified.
  Nothing = 0,
+
  // If two separators follow each other without any characters
- // in between, keep a "" in the resulting vector.
+ // in between, keep a "" in the resulting vector. (or only the
+ // separator if KeepTrailingSeparator is used)
  KeepEmpty = 1,
+
+ // Do not strip off the separator at the end of the string.
+ KeepTrailingSeparator = 2,
 };
 AK_ENUM_BITWISE_OPERATORS(SplitBehavior);
 

diff --git a/AK/StringView.cpp b/AK/StringView.cpp
@@ -272,12 +272,13 @@ Vector<StringView> StringView::split_view_if(Function<bool(char)> const& predica
  Vector<StringView> v;
  size_t substart = 0;
  bool keep_empty = has_flag(split_behavior, SplitBehavior::KeepEmpty);
+ bool keep_separator = has_flag(split_behavior, SplitBehavior::KeepTrailingSeparator);
  for (size_t i = 0; i < length(); ++i) {
  char ch = characters_without_null_termination()[i];
  if (predicate(ch)) {
  size_t sublen = i - substart;
  if (sublen != 0 || keep_empty)
- v.append(substring_view(substart, sublen));
+ v.append(substring_view(substart, keep_separator ? sublen + 1 : sublen));
  substart = i + 1;
  }
  }

diff --git a/AK/StringView.h b/AK/StringView.h
@@ -170,11 +170,16 @@ class StringView {
 
  auto maybe_separator_index = find(separator);
  bool keep_empty = has_flag(split_behavior, SplitBehavior::KeepEmpty);
+ bool keep_separator = has_flag(split_behavior, SplitBehavior::KeepTrailingSeparator);
  while (maybe_separator_index.has_value()) {
  auto separator_index = maybe_separator_index.value();
  auto part_with_separator = view.substring_view(0, separator_index + separator.length());
- if (keep_empty || separator_index > 0)
- callback(part_with_separator.substring_view(0, separator_index));
+ if (keep_empty || separator_index > 0) {
+ if (keep_separator)
+ callback(part_with_separator);
+ else
+ callback(part_with_separator.substring_view(0, separator_index));
+ }
  view = view.substring_view_starting_after_substring(part_with_separator);
  maybe_separator_index = view.find(separator);
  }

diff --git a/Tests/AK/TestStringView.cpp b/Tests/AK/TestStringView.cpp
@@ -163,6 +163,11 @@ TEST_CASE(split_view)
  EXPECT_EQ(test_string_view.split_view_if(predicate, SplitBehavior::KeepEmpty), Vector({ "a"sv, ""sv, "b"sv, "c"sv, "d"sv }));
  EXPECT_EQ(test_string_view.split_view_if(predicate), Vector({ "a"sv, "b"sv, "c"sv, "d"sv }));
  EXPECT_EQ(test_string_view.split_view_if(predicate, SplitBehavior::KeepEmpty), Vector({ "a"sv, ""sv, "b"sv, "c"sv, "d"sv }));
+
+ test_string_view = "a,,,b"sv;
+ EXPECT_EQ(test_string_view.split_view(","sv, SplitBehavior::KeepEmpty), Vector({ "a"sv, ""sv, ""sv, "b"sv }));
+ EXPECT_EQ(test_string_view.split_view(","sv, SplitBehavior::KeepTrailingSeparator), Vector({ "a,"sv, "b"sv }));
+ EXPECT_EQ(test_string_view.split_view(","sv, SplitBehavior::KeepTrailingSeparator | SplitBehavior::KeepEmpty), Vector({ "a,"sv, ","sv, ","sv, "b"sv }));
 }
 
 TEST_CASE(constexpr_stuff)