From 13026c70ca0c947c41b8002e548bc22d64bd00d4 Mon Sep 17 00:00:00 2001
From: Allan Odgaard <git@abetarda.com>
Date: Fri, 24 Aug 2012 21:42:20 +0200
Subject: [PATCH] Add format_string::escape

This produces a string where all format string characters have been properly escaped.
---
 Frameworks/regexp/src/format_string.cc     | 26 ++++++++++++++++++++++
 Frameworks/regexp/src/format_string.h      |  1 +
 Frameworks/regexp/tests/t_format_string.cc | 14 ++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/Frameworks/regexp/src/format_string.cc b/Frameworks/regexp/src/format_string.cc
index 44c6a69d..738859ad 100644
--- a/Frameworks/regexp/src/format_string.cc
+++ b/Frameworks/regexp/src/format_string.cc
@@ -296,6 +296,32 @@ namespace format_string
 		return format_string_t(format).expand(variables);
 	}
 
+	std::string escape (std::string const& format)
+	{
+		std::string res = "";
+		for(size_t i = 0; i < format.size(); ++i)
+		{
+			switch(format[i])
+			{
+				case '\t': res.append("\\t"); break;
+				case '\r': res.append("\\r"); break;
+				case '\n': res.append("\\n"); break;
+
+				case '$': case '(': case '\\':
+				{
+					if(format[i] != '\\' || i+1 != format.size() && strchr("\\$(trn", format[i+1]))
+						res.append("\\");
+				}
+				/* continue */
+
+				default:
+					res += format[i];
+				break;
+			}
+		}
+		return res;
+	}
+
 } /* format_string */
 
 namespace snippet
diff --git a/Frameworks/regexp/src/format_string.h b/Frameworks/regexp/src/format_string.h
index 52c473d0..6a838b4c 100644
--- a/Frameworks/regexp/src/format_string.h
+++ b/Frameworks/regexp/src/format_string.h
@@ -29,6 +29,7 @@ namespace format_string
 
 	PUBLIC std::string replace (std::string const& src, regexp::pattern_t const& ptrn, format_string_t const& format, bool repeat = true, string_map_t const& variables = string_map_t());
 	PUBLIC std::string expand (std::string const& format, string_map_t const& variables = string_map_t());
+	PUBLIC std::string escape (std::string const& format);
 
 } /* format_string */
 
diff --git a/Frameworks/regexp/tests/t_format_string.cc b/Frameworks/regexp/tests/t_format_string.cc
index 39153566..39914d77 100644
--- a/Frameworks/regexp/tests/t_format_string.cc
+++ b/Frameworks/regexp/tests/t_format_string.cc
@@ -24,4 +24,18 @@ public:
 		TS_ASSERT_EQUALS(replace("foo bar", "(foo)? bar", "(?n:baz)"),             "(?n:baz)");
 		TS_ASSERT_EQUALS(replace("foo bar", "(foo)? bar", "(?n:baz:)"),            "(?n:baz:)");
 	}
+
+	void test_escape_format_string ()
+	{
+		using format_string::escape;
+		using format_string::expand;
+		TS_ASSERT_EQUALS(escape("\t\n\r\\q"),               "\\t\\n\\r\\q");
+		TS_ASSERT_EQUALS(expand(escape("${var}")),                "${var}");
+		TS_ASSERT_EQUALS(expand(escape("foo\n")),                  "foo\n");
+		TS_ASSERT_EQUALS(expand(escape("foo\\n")),                "foo\\n");
+		TS_ASSERT_EQUALS(expand(escape("\\No-Escape")),      "\\No-Escape");
+		TS_ASSERT_EQUALS(expand(escape("(?bla)")),                "(?bla)");
+		TS_ASSERT_EQUALS(expand(escape("Escape\\\\me")),    "Escape\\\\me");
+		TS_ASSERT_EQUALS(expand(escape("(?1:baz: buz)")),  "(?1:baz: buz)");
+	}
 };