Added generic trim function

2 files changed, 49 insertions, 14 deletions

diff --git a/src/core/common/Utils.cpp b/src/core/common/Utils.cpp
index c8fcdc6..f59061a 100644
--- a/src/core/common/Utils.cpp
+++ b/src/core/common/Utils.cpp
@@ -27,20 +27,8 @@ namespace ousia {
 
 std::string Utils::trim(const std::string &s)
 {
-	size_t firstNonWhitespace = std::numeric_limits<size_t>::max();
-	size_t lastNonWhitespace = 0;
-	for (size_t i = 0; i < s.size(); i++) {
-		if (!isWhitespace(s[i])) {
-			firstNonWhitespace = std::min(i, firstNonWhitespace);
-			lastNonWhitespace = std::max(i, lastNonWhitespace);
-		}
-	}
-
-	if (firstNonWhitespace < lastNonWhitespace) {
-		return s.substr(firstNonWhitespace,
-		                lastNonWhitespace - firstNonWhitespace + 1);
-	}
-	return std::string{};
+	std::pair<size_t, size_t> bounds = trim(s, Utils::isWhitespace);
+	return s.substr(bounds.first, bounds.second - bounds.first);
 }
 
 bool Utils::isIdentifier(const std::string &name)
diff --git a/src/core/common/Utils.hpp b/src/core/common/Utils.hpp
index 22e0fd3..f6f5225 100644
--- a/src/core/common/Utils.hpp
+++ b/src/core/common/Utils.hpp
@@ -71,11 +71,58 @@ public:
 	}
 
 	/**
+	 * Returns true if the given character is a whitespace character.
+	 */
+	static bool isLinebreak(const char c)
+	{
+		return (c == '\n') || (c == '\r');
+	}
+
+	/**
 	 * Removes whitespace at the beginning and the end of the given string.
+	 *
+	 * @param s is the string that should be trimmed.
+	 * @return a trimmed copy of s.
 	 */
 	static std::string trim(const std::string &s);
 
 	/**
+	 * Trims the given string or vector of chars by returning the start and end
+	 * index.
+	 *
+	 * @param s is the container that should be trimmed.
+	 * @param f is a function that returns true for values that should be
+	 * removed.
+	 * @return start and end index. Note that "end" points at the character beyond
+	 * the end, thus "end" minus "start"
+	 */
+	template <class T, class Filter>
+	static std::pair<size_t, size_t> trim(const T &s, Filter f) {
+		size_t start = 0;
+		for (size_t i = 0; i < s.size(); i++) {
+			if (!f(s[i])) {
+				start = i;
+				break;
+			}
+		}
+
+		size_t end = 0;
+		for (ssize_t i = s.size() - 1; i >= static_cast<ssize_t>(start); i--) {
+			if (!f(s[i])) {
+				end = i + 1;
+				break;
+			}
+		}
+
+		if (end < start) {
+			start = 0;
+			end = 0;
+		}
+
+		return std::pair<size_t, size_t>{start, end};
+	}
+
+	/**
 	 * Turns the elements of a collection into a string separated by the
 	 * given delimiter.
 	 *