Move string distance function to utils and format error message

6 files changed, 122 insertions, 52 deletions

diff --git a/libdevcore/StringUtils.cpp b/libdevcore/StringUtils.cpp
new file mode 100644
index 00000000..7b2b4f5e
--- /dev/null
+++ b/libdevcore/StringUtils.cpp
@@ -0,0 +1,77 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/** @file StringUtils.h
+ * @author Balajiganapathi S <balajiganapathi.s@gmail.com>
+ * @date 2017
+ *
+ * String routines
+ */
+
+#include "StringUtils.h"
+#include <algorithm>
+#include <string>
+#include <vector>
+
+using namespace std;
+using namespace dev;
+
+namespace dev
+{
+
+bool stringWithinDistance(string const& _name1, string const& _name2, size_t _maxDistance)
+{
+	if (_name1 == _name2)
+		return true;
+
+	size_t n1 = _name1.size(), n2 = _name2.size();
+	vector<vector<size_t>> dp(n1 + 1, vector<size_t>(n2 + 1));
+
+	// In this dp formulation of Damerau–Levenshtein distance we are assuming that the strings are 1-based to make base case storage easier.
+	// So index accesser to _name1 and _name2 have to be adjusted accordingly
+	for (size_t i1 = 0; i1 <= n1; ++i1)
+	{
+		for (size_t i2 = 0; i2 <= n2; ++i2)
+		{
+			if (min(i1, i2) == 0)
+				// Base case
+				dp[i1][i2] = max(i1, i2);
+			else
+			{
+				dp[i1][i2] = min(dp[i1 - 1][i2] + 1, dp[i1][i2 - 1] + 1);
+				// Deletion and insertion
+				if (_name1[i1 - 1] == _name2[i2 - 1])
+					// Same chars, can skip
+					dp[i1][i2] = min(dp[i1][i2], dp[i1 - 1][i2 - 1]);
+				else
+					// Different chars so try substitution
+					dp[i1][i2] = min(dp[i1][i2], dp[i1 - 1][i2 - 1] + 1);
+
+				if (i1 > 1 && i2 > 1 && _name1[i1 - 1] == _name2[i2 - 2] && _name1[i1 - 2] == _name2[i2 - 1])
+					// Try transposing
+					dp[i1][i2] = min(dp[i1][i2], dp[i1 - 2][i2 - 2] + 1);
+			}
+		}
+	}
+
+	size_t distance = dp[n1][n2];
+
+	// if distance is not greater than _maxDistance, and distance is strictly less than length of both names,
+	// they can be considered similar this is to avoid irrelevant suggestions
+	return distance <=  _maxDistance && distance < n1 && distance < n2;
+}
+
+}
diff --git a/libdevcore/StringUtils.h b/libdevcore/StringUtils.h
new file mode 100644
index 00000000..d3f9f8d9
--- /dev/null
+++ b/libdevcore/StringUtils.h
@@ -0,0 +1,35 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/** @file StringUtils.h
+ * @author Balajiganapathi S <balajiganapathi.s@gmail.com>
+ * @date 2017
+ *
+ * String routines
+ */
+
+#pragma once
+
+#include <string>
+
+namespace dev
+{
+
+/// Calculates the Damerau–Levenshtein distance between @a _name1 and @a _name2 and
+/// @returns true if that distance is not greater than @a _maxDistance
+bool stringWithinDistance(std::string const& _name1, std::string const& _name2, size_t _maxDistance);
+
+}
diff --git a/libsolidity/analysis/DeclarationContainer.cpp b/libsolidity/analysis/DeclarationContainer.cpp
index d41bc7d3..f9a52dc6 100644
--- a/libsolidity/analysis/DeclarationContainer.cpp
+++ b/libsolidity/analysis/DeclarationContainer.cpp
@@ -23,6 +23,7 @@
 #include <libsolidity/analysis/DeclarationContainer.h>
 #include <libsolidity/ast/AST.h>
 #include <libsolidity/ast/Types.h>
+#include <libdevcore/StringUtils.h>
 
 using namespace std;
 using namespace dev;
@@ -123,7 +124,7 @@ vector<ASTString> DeclarationContainer::similarNames(ASTString const& _name) con
 	for (auto const& declaration: m_declarations)
 	{
 		string const& declarationName = declaration.first;
-		if (DeclarationContainer::areSimilarNames(_name, declarationName))
+		if (stringWithinDistance(_name, declarationName, MAXIMUM_DISTANCE))
 			similar.push_back(declarationName);
 	}
 
@@ -135,44 +136,3 @@ vector<ASTString> DeclarationContainer::similarNames(ASTString const& _name) con
 
 	return similar;
 }
-
-bool DeclarationContainer::areSimilarNames(ASTString const& _name1, ASTString const& _name2)
-{
-	if (_name1 == _name2)
-		return true;
-
-	size_t n1 = _name1.size(), n2 = _name2.size();
-	vector<vector<size_t>> dp(n1 + 1, vector<size_t>(n2 + 1));
-
-	// In this dp formulation of Damerau–Levenshtein distance we are assuming that the strings are 1-based to make base case storage easier.
-	// So index accesser to _name1 and _name2 have to be adjusted accordingly
-	for (size_t i1 = 0; i1 <= n1; ++i1)
-	{
-		for (size_t i2 = 0; i2 <= n2; ++i2)
-		{
-				if (min(i1, i2) == 0) // base case
-					dp[i1][i2] = max(i1, i2);
-				else
-				{
-					dp[i1][i2] = min(dp[i1-1][i2] + 1, dp[i1][i2-1] + 1);
-					// Deletion and insertion
-					if (_name1[i1-1] == _name2[i2-1])
-						// Same chars, can skip
-						dp[i1][i2] = min(dp[i1][i2], dp[i1-1][i2-1]);
-					else
-						// Different chars so try substitution
-						dp[i1][i2] = min(dp[i1][i2], dp[i1-1][i2-1] + 1);
-
-					if (i1 > 1 && i2 > 1 && _name1[i1-1] == _name2[i2-2] && _name1[i1-2] == _name2[i2-1])
-						// Try transposing
-						dp[i1][i2] = min(dp[i1][i2], dp[i1-2][i2-2] + 1);
-				}
-		}
-	}
-
-	size_t distance = dp[n1][n2];
-
-	// If distance is not greater than MAXIMUM_DISTANCE, and distance is strictly less than length of both names,
-	// they can be considered similar this is to avoid irrelevant suggestions
-	return distance <= MAXIMUM_DISTANCE && distance < n1 && distance < n2;
-}
diff --git a/libsolidity/analysis/DeclarationContainer.h b/libsolidity/analysis/DeclarationContainer.h
index 991140d8..6c1459c7 100644
--- a/libsolidity/analysis/DeclarationContainer.h
+++ b/libsolidity/analysis/DeclarationContainer.h
@@ -68,8 +68,6 @@ private:
 	std::map<ASTString, std::vector<Declaration const*>> m_declarations;
 	std::map<ASTString, std::vector<Declaration const*>> m_invisibleDeclarations;
 
-	// Calculates the Damerau–Levenshtein distance and decides whether the two names are similar
-	static bool areSimilarNames(ASTString const& _name1, ASTString const& _name2);
 	static size_t const MAXIMUM_DISTANCE = 2;
 };
 
diff --git a/libsolidity/analysis/NameAndTypeResolver.cpp b/libsolidity/analysis/NameAndTypeResolver.cpp
index a9a62529..21f2af5f 100644
--- a/libsolidity/analysis/NameAndTypeResolver.cpp
+++ b/libsolidity/analysis/NameAndTypeResolver.cpp
@@ -431,13 +431,13 @@ string NameAndTypeResolver::similarNameSuggestions(ASTString const& _name) const
 	if (suggestions.empty())
 		return "";
 	if (suggestions.size() == 1)
-		return suggestions.front();
+		return "\"" + suggestions.front() + "\"";
 
-	string choices = suggestions.front();
+	string choices = "\"" + suggestions.front() + "\"";
 	for (size_t i = 1; i + 1 < suggestions.size(); ++i)
-		choices += ", " + suggestions[i];
+		choices += ", \"" + suggestions[i] + "\"";
 
-	choices += " or " + suggestions.back();
+	choices += " or \"" + suggestions.back() + "\"";
 
 	return choices;
 }
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 51d81a28..c4741657 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -2089,7 +2089,7 @@ BOOST_AUTO_TEST_CASE(similar_name_suggestions_expected)
 			function g() public { fun(); }
 		}
 	)";
-	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean func?");
+	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean \"func\"?");
 }
 
 BOOST_AUTO_TEST_CASE(no_name_suggestion)
@@ -2115,7 +2115,7 @@ BOOST_AUTO_TEST_CASE(multiple_similar_suggestions)
 			}
 		}
 	)";
-	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean var1, var2, var3, var4 or var5?");
+	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean \"var1\", \"var2\", \"var3\", \"var4\" or \"var5\"?");
 }
 
 BOOST_AUTO_TEST_CASE(multiple_scopes_suggestions)
@@ -2129,7 +2129,7 @@ BOOST_AUTO_TEST_CASE(multiple_scopes_suggestions)
 			}
 		}
 	)";
-	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean log8, log9, log0, log1, log2, log3 or log4?");
+	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean \"log8\", \"log9\", \"log0\", \"log1\", \"log2\", \"log3\" or \"log4\"?");
 }
 
 BOOST_AUTO_TEST_CASE(inheritence_suggestions)
@@ -2142,7 +2142,7 @@ BOOST_AUTO_TEST_CASE(inheritence_suggestions)
 			}
 		}
 	)";
-	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean func?");
+	CHECK_ERROR(sourceCode, DeclarationError, "Undeclared identifier. Did you mean \"func\"?");
 }
 
 BOOST_AUTO_TEST_CASE(no_spurious_suggestions)