Add next_word() overload that doesn't skip consecutive delimiters

In particular, this version can be used to parse lines while observing
blanks.

2 files changed, 52 insertions, 0 deletions

diff --git a/tests/next-word/buildfile b/tests/next-word/buildfile
new file mode 100644
index 0000000..e06cd88
--- /dev/null
+++ b/tests/next-word/buildfile
@@ -0,0 +1,6 @@
+# file      : tests/next-word/buildfile
+# license   : MIT; see accompanying LICENSE file
+
+import libs = libbutl%lib{butl}
+
+exe{driver}: {hxx cxx}{*} $libs
diff --git a/tests/next-word/driver.cxx b/tests/next-word/driver.cxx
new file mode 100644
index 0000000..4ebe1a5
--- /dev/null
+++ b/tests/next-word/driver.cxx
@@ -0,0 +1,46 @@
+// file      : tests/next-word/driver.cxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#include <vector>
+#include <string>
+//#include <iostream>
+
+#include <libbutl/utility.hxx>
+
+#undef NDEBUG
+#include <cassert>
+
+using namespace std;
+using namespace butl;
+
+using strings = vector<string>;
+
+static strings
+parse_lines (const string& s)
+{
+  strings r;
+  for (size_t b (0), e (0), m (0), n (s.size ());
+       next_word (s, n, b, e, m, '\n', '\r'), b != n; )
+  {
+    //cerr << "'" << string (s, b, e - b) << "'" << endl;
+    r.push_back (string (s, b, e - b));
+  }
+  return r;
+}
+
+int
+main ()
+{
+  assert ((parse_lines("") == strings {}));
+  assert ((parse_lines("a") == strings {"a"}));
+  assert ((parse_lines("\n") == strings {"", ""}));
+  assert ((parse_lines("\n\n") == strings {"", "", ""}));
+  assert ((parse_lines("\n\n\n") == strings {"", "", "", ""}));
+  assert ((parse_lines("\na") == strings {"", "a"}));
+  assert ((parse_lines("\n\na") == strings {"", "", "a"}));
+  assert ((parse_lines("a\n") == strings {"a", ""}));
+  assert ((parse_lines("a\n\n") == strings {"a", "", ""}));
+  assert ((parse_lines("a\nb") == strings {"a", "b"}));
+  assert ((parse_lines("a\n\nb") == strings {"a", "", "b"}));
+  assert ((parse_lines("\na\nb\n") == strings {"", "a", "b", ""}));
+}