From 1913620f37c686e9a605ea343f9d9a0dd6ce0af9 Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Thu, 4 Feb 2016 23:30:49 +0100
Subject: [PATCH] integrate new stringify() variant and add test coverage

...also for the existing variant, which packages an
arbitrary number of arguments in stringified form
into a given container type. Moreover, the new
form of stringify allows to write util::join
in a clearer way, eliminating the lambda.
---
 src/lib/format-util.hpp              | 20 +++++++++++++++-----
 tests/library/format-helper-test.cpp | 16 ++++++++--------
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/src/lib/format-util.hpp b/src/lib/format-util.hpp
index 5af1f0efa..b70bc0b5c 100644
--- a/src/lib/format-util.hpp
+++ b/src/lib/format-util.hpp
@@ -121,6 +121,20 @@ namespace util {
     return CON {move(storage)};
   }
   
+  /** convert to string as transforming step in a pipeline
+   * @param src a "Lumiera Forward Iterator" with arbitrary result type
+   * @return a "Lumiera Forward Iterator" with string elements
+   * @see FormatHelper_test::checkStringify()
+   */
+  template<class IT>
+  inline lib::TransformIter<IT, string>
+  stringify (IT const& src)
+  {
+    using Val =  typename IT::value_type;
+    
+    return lib::transformIterator(src, util::toString<Val>);
+  }
+  
   
   
   namespace { // helper to build range iterator on demand
@@ -175,13 +189,9 @@ namespace util {
   join (CON&& coll, string const& delim =", ")
   {
     using Coll = typename lib::meta::Strip<CON>::TypePlain;
-    using Val =  typename Coll::value_type;
-    
-    std::function<string(Val const&)> toString = [] (Val const& val) { return util::toString(val); };
-    
     _RangeIter<Coll> range(std::forward<CON>(coll));
-    auto strings = lib::transformIterator(range.iter, toString);
     
+    auto strings = stringify (range.iter);
     if (!strings) return "";
     
     std::ostringstream buffer;
diff --git a/tests/library/format-helper-test.cpp b/tests/library/format-helper-test.cpp
index 1b4075d8d..753baebcb 100644
--- a/tests/library/format-helper-test.cpp
+++ b/tests/library/format-helper-test.cpp
@@ -42,14 +42,6 @@ using std::to_string;
 
 
 namespace util {
-  template<class IT>
-  inline lib::TransformIter<IT, string>
-  stringify (IT const& src)
-  {
-    using Val =  typename IT::value_type;
-    
-    return transformIterator(src, util::toString<Val>);
-  }
 namespace test {
   
   namespace { // test fixture...
@@ -141,6 +133,7 @@ namespace test {
       void
       checkStringify()
         {
+          // use as transformer within an (iterator) pipeline
           auto ss = stringify (eachNum (1.11, 10.2));
           
           CHECK (ss);
@@ -153,6 +146,13 @@ namespace test {
             res += s;
           
           CHECK (res == "..2.113.114.115.116.117.118.119.1110.11");
+          
+          
+          using VecS = vector<string>;
+          
+          // another variant: collect arbitrary number of arguments
+          VecS vals = stringify<VecS> (short(12), 345L, "67", '8');
+          CHECK (vals == VecS({"12", "345", "67", "8"}));
         }