comparison DEPENDENCIES/generic/include/boost/pending/stringtok.hpp @ 16:2665513ce2d3

Add boost headers

+//  (C) Copyright Jeremy Siek 2004 
+//  Distributed under the Boost Software License, Version 1.0. (See
+//  accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_STRINGTOK_HPP
+#define BOOST_STRINGTOK_HPP
+
+/*
+ * stringtok.hpp -- Breaks a string into tokens.  This is an example for lib3.
+ *
+ * Template function looks like this:
+ *
+ *    template <typename Container>
+ *    void stringtok (Container &l,
+ *                    string const &s,
+ *                    char const * const ws = " \t\n");
+ *
+ * A nondestructive version of strtok() that handles its own memory and can
+ * be broken up by any character(s).  Does all the work at once rather than
+ * in an invocation loop like strtok() requires.
+ *
+ * Container is any type that supports push_back(a_string), although using
+ * list<string> and deque<string> are indicated due to their O(1) push_back.
+ * (I prefer deque<> because op[]/at() is available as well.)  The first
+ * parameter references an existing Container.
+ *
+ * s is the string to be tokenized.  From the parameter declaration, it can
+ * be seen that s is not affected.  Since references-to-const may refer to
+ * temporaries, you could use stringtok(some_container, readline("")) when
+ * using the GNU readline library.
+ *
+ * The final parameter is an array of characters that serve as whitespace.
+ * Whitespace characters default to one or more of tab, space, and newline,
+ * in any combination.
+ *
+ * 'l' need not be empty on entry.  On return, 'l' will have the token
+ * strings appended.
+ *
+ *
+ * [Example:
+ *       list<string>       ls;
+ *       stringtok (ls, " this  \t is\t\n  a test  ");
+ *       for (list<string>::const_iterator i = ls.begin();
+ *            i != ls.end(); ++i)
+ *       {
+ *            cerr << ':' << (*i) << ":\n";
+ *       }
+ *
+ *  would print
+ *       :this:
+ *       :is:
+ *       :a:
+ *       :test:
+ * -end example]
+ *
+ * [e-mail]  May 1999
+*/
+
+
+#include <string>
+#include <cstring>    // for strchr
+
+
+/*****************************************************************
+ * This is the only part of the implementation that I don't like.
+ * It can probably be improved upon by the reader...
+*/
+
+    inline bool
+    isws (char c, char const * const wstr)
+    {
+        using namespace std;
+        return (strchr(wstr,c) != NULL);
+    }
+
+
+namespace boost {
+
+/*****************************************************************
+ * Simplistic and quite Standard, but a bit slow.  This should be
+ * templatized on basic_string instead, or on a more generic StringT
+ * that just happens to support ::size_type, .substr(), and so on.
+ * I had hoped that "whitespace" would be a trait, but it isn't, so
+ * the user must supply it.  Enh, this lets them break up strings on
+ * different things easier than traits would anyhow.
+*/
+template <typename Container>
+void
+stringtok (Container &l, std::string const &s, char const * const ws = " \t\n")
+{
+  typedef std::string::size_type size_type;
+    const size_type  S = s.size();
+          size_type  i = 0;
+
+    while (i < S) {
+        // eat leading whitespace
+        while ((i < S) && (isws(s[i],ws)))  ++i;
+        if (i == S)  return;  // nothing left but WS
+
+        // find end of word
+        size_type  j = i+1;
+        while ((j < S) && (!isws(s[j],ws)))  ++j;
+
+        // add word
+        l.push_back(s.substr(i,j-i));
+
+        // set up for next loop
+        i = j+1;
+    }
+}
+
+
+} // namespace boost
+
+#endif // BOOST_STRINGTOK_HPP