From 86ce5f1da50e7de9c4d0649273637adda10f46b9 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Mon, 29 Nov 2021 21:19:41 +0100
Subject: [PATCH] Use LineColumn type.

---
 liblangutil/CharStream.cpp             |  4 ++--
 liblangutil/CharStream.h               |  3 ++-
 liblangutil/SourceLocation.h           | 19 +++++++++++++++++++
 liblangutil/SourceReferenceExtractor.h |  9 ---------
 4 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/liblangutil/CharStream.cpp b/liblangutil/CharStream.cpp
index 3b30bad77..96a6aebe2 100644
--- a/liblangutil/CharStream.cpp
+++ b/liblangutil/CharStream.cpp
@@ -100,7 +100,7 @@ string CharStream::lineAtPosition(int _position) const
 	return line;
 }
 
-tuple<int, int> CharStream::translatePositionToLineColumn(int _position) const
+LineColumn CharStream::translatePositionToLineColumn(int _position) const
 {
 	using size_type = string::size_type;
 	using diff_type = string::difference_type;
@@ -114,7 +114,7 @@ tuple<int, int> CharStream::translatePositionToLineColumn(int _position) const
 		lineStart = m_source.rfind('\n', searchPosition - 1);
 		lineStart = lineStart == string::npos ? 0 : lineStart + 1;
 	}
-	return tuple<int, int>(lineNumber, searchPosition - lineStart);
+	return LineColumn{lineNumber, static_cast<int>(searchPosition - lineStart)};
 }
 
 string_view CharStream::text(SourceLocation const& _location) const
diff --git a/liblangutil/CharStream.h b/liblangutil/CharStream.h
index 761cece31..2e5d79d93 100644
--- a/liblangutil/CharStream.h
+++ b/liblangutil/CharStream.h
@@ -59,6 +59,7 @@ namespace solidity::langutil
 {
 
 struct SourceLocation;
+struct LineColumn;
 
 /**
  * Bidirectional stream of characters.
@@ -97,7 +98,7 @@ public:
 	/// Functions that help pretty-printing parse errors
 	/// Do only use in error cases, they are quite expensive.
 	std::string lineAtPosition(int _position) const;
-	std::tuple<int, int> translatePositionToLineColumn(int _position) const;
+	LineColumn translatePositionToLineColumn(int _position) const;
 	///@}
 
 	/// Tests whether or not given octet sequence is present at the current position in stream.
diff --git a/liblangutil/SourceLocation.h b/liblangutil/SourceLocation.h
index ea9958933..ddb457535 100644
--- a/liblangutil/SourceLocation.h
+++ b/liblangutil/SourceLocation.h
@@ -119,4 +119,23 @@ SourceLocation parseSourceLocation(
 /// Stream output for Location (used e.g. in boost exceptions).
 std::ostream& operator<<(std::ostream& _out, SourceLocation const& _location);
 
+
+/**
+ * Alternative, line-column-based representation for source locations.
+ * Both line and column are zero-based.
+ * If used as a range, the second location is considered exclusive.
+ * Negative values are invalid.
+ */
+struct LineColumn
+{
+	/// Line value, can be between zero and number of `\n` characters in the source file.
+	int line = -1;
+	/// Column value, can be between zero and number of characters in the line (inclusive).
+	int column = -1;
+
+	LineColumn() = default;
+	explicit LineColumn(int _line, int _column): line(_line), column(_column) {}
+};
+
+
 }
diff --git a/liblangutil/SourceReferenceExtractor.h b/liblangutil/SourceReferenceExtractor.h
index 6aeb6065e..3b418fcfa 100644
--- a/liblangutil/SourceReferenceExtractor.h
+++ b/liblangutil/SourceReferenceExtractor.h
@@ -30,15 +30,6 @@ namespace solidity::langutil
 
 class CharStreamProvider;
 
-struct LineColumn
-{
-	int line = {-1};
-	int column = {-1};
-
-	LineColumn() = default;
-	LineColumn(std::tuple<int, int> const& _t): line{std::get<0>(_t)}, column{std::get<1>(_t)} {}
-};
-
 struct SourceReference
 {
 	std::string message;      ///< A message that relates to this source reference (such as a warning, info or an error message).