Move escape_non_alnum() to util/string_utils.{h,cpp}

The function is generally useful for obtaining strings that contain only
alphanumeric characters.

Author: danpoe

jbmc/src/java_bytecode/java_string_literals.cpp

@@ -15,34 +15,12 @@ Author: Chris Smowton, [email protected]
 #include <util/arith_tools.h>
 #include <util/expr_initializer.h>
 #include <util/namespace.h>
+#include <util/string_utils.h>
 #include <util/unicode.h>
 
 #include <iomanip>
 #include <sstream>
 
-/// Replace non-alphanumeric characters with `_xx` escapes, where xx are hex
-/// digits. Underscores are replaced by `__`.
-/// \param to_escape: string to escape
-/// \return string with non-alphanumeric characters escaped
-static std::string escape_non_alnum(const std::string &to_escape)
-{
-  std::ostringstream escaped;
-  for(auto &ch : to_escape)
-  {
-    if(ch=='_')
-      escaped << "__";
-    else if(isalnum(ch))
-      escaped << ch;
-    else
-      escaped << '_'
-              << std::hex
-              << std::setfill('0')
-              << std::setw(2)
-              << (unsigned int)ch;
-  }
-  return escaped.str();
-}
-
 /// Convert UCS-2 or UTF-16 to an array expression.
 /// \par parameters: `in`: wide string to convert
 /// \return Returns a Java char array containing the same wchars.

src/util/string_utils.cpp

@@ -10,9 +10,10 @@ Author: Daniel Poetzl
 #include "exception_utils.h"
 #include "invariant.h"
 
+#include <algorithm>
 #include <cassert>
 #include <cctype>
-#include <algorithm>
+#include <iomanip>
 
 /// Remove all whitespace characters from either end of a string. Whitespace
 /// in the middle of the string is left unchanged
@@ -159,3 +160,19 @@ std::string escape(const std::string &s)
 
   return result;
 }
+
+std::string escape_non_alnum(const std::string &to_escape)
+{
+  std::ostringstream escaped;
+  for(auto &ch : to_escape)
+  {
+    if(ch == '_')
+      escaped << "__";
+    else if(isalnum(ch))
+      escaped << ch;
+    else
+      escaped << '_' << std::hex << std::setfill('0') << std::setw(2)
+              << (unsigned int)ch;
+  }
+  return escaped.str();
+}

src/util/string_utils.h

@@ -96,4 +96,10 @@ join_strings(Stream &&os, const It b, const It e, const Delimiter &delimiter)
 /// programming language.
 std::string escape(const std::string &);
 
+/// Replace non-alphanumeric characters with `_xx` escapes, where xx are hex
+/// digits. Underscores are replaced by `__`.
+/// \param to_escape: string to escape
+/// \return string with non-alphanumeric characters escaped
+std::string escape_non_alnum(const std::string &to_escape);
+
 #endif