Add names to positional arguments

README.md

@@ -122,6 +122,11 @@ Identifiers are used to find arguments from command line and provide a descripti
 * Example: `int fired_main(int x = fire::arg(0));`
     * CLI usage: `program 1`
 
+
+* Example: `int fired_main(int x = fire::arg(0, "<first>"));`
+    * CLI usage: `program 1`
+    * name `<first>` appears in help and error messages
+
 #### <a id="description"></a> D.2.2 Descrpition (in identifier)
 
 Argument description for `--help` message. Is determined by not having leading hyphens.
@@ -202,7 +207,6 @@ v0.1 release is tested on:
 
 #### Current status
 
-* Names for positional arguments for help message
 * Automatic testing for error messages
 * Improve help messages
     * Refactor `log_elem::type` from `std::string` -> `enum class`

examples/positional.cpp

@@ -20,8 +20,8 @@
 using namespace std;
 
 int fired_main(
-        int x0 = fire::arg({0, "Zeroth argument"}),
-        fire::optional<int> x1 = fire::arg({1, "First argument"})
+        int x0 = fire::arg({0, "<first>", "First argument"}),
+        fire::optional<int> x1 = fire::arg({1, "<second>", "Second argument"})
         ) {
     std::cout << x0 << " " << x1.value_or(0) << endl;
     return 0;

fire.hpp

@@ -72,7 +72,7 @@ namespace fire {
 
     class identifier {
         optional<int> _pos;
-        optional<std::string> _short_name, _long_name, _descr;
+        optional<std::string> _short_name, _long_name, _pos_name, _descr;
         bool _vector = false;
         bool _optional = false; // Only use for operator<
 
@@ -305,6 +305,11 @@ namespace fire {
     inline identifier::identifier(const std::vector<std::string> &names, optional<int> pos) {
         // Find description, shorthand and long name
         for(const std::string &name: names) {
+            if(name.size() >= 2 && name.front() == '<' && name.back() == '>') {
+                _pos_name = name;
+                continue;
+            }
+
             int hyphens = count_hyphens(name);
             _instant_assert(hyphens <= 2, "Identifier entry " + name + " must prefix either:"
                                           " 0 hyphens for description,"
@@ -347,10 +352,17 @@ namespace fire {
             _instant_assert(! _long_name.has_value(),
                     "Can't specify both name " + _long_name.value_or("") + " and index " + std::to_string(pos.value()));
             _pos = pos;
-            _longer = _help = "<" + std::to_string(pos.value()) + ">";
+            if(_pos_name.has_value())
+                _longer = _help = _pos_name.value();
+            else
+                _longer = _help = "<" + std::to_string(pos.value()) + ">";
         }
         _instant_assert(_short_name.has_value() || _long_name.has_value() || _pos.has_value(),
                 "Argument must be specified with at least on of the following: shorthand, long name or index");
+
+        if(_pos_name.has_value())
+            _instant_assert(_pos.has_value(),
+                    "Positional name " + _pos_name.value_or("") + " requires the argument to be positional");
     }
 
     bool identifier::operator<(const identifier &other) const {

tests/tests.cpp

@@ -185,7 +185,9 @@ TEST(identifier, help) {
     EXPECT_EQ(identifier(vector<string>{"-l", "--long"}, empty).help(), "-l|--long");
     EXPECT_EQ(identifier(vector<string>{"--long"}, empty).help(), "--long");
 
-    EXPECT_EQ(identifier(vector<string>{"zeroth"}, 0).help(), "<0>");
+    EXPECT_EQ(identifier(vector<string>{"description"}, 0).help(), "<0>");
+    EXPECT_EQ(identifier(vector<string>{"<name>", "description"}, 0).help(), "<name>");
+    EXPECT_EQ(identifier(vector<string>{"<name>"}, 0).help(), "<name>");
     EXPECT_EQ(identifier().help(), "...");
 }
 
@@ -197,6 +199,7 @@ TEST(identifier, longer) {
     EXPECT_EQ(identifier(vector<string>{"--long"}, empty).longer(), "--long");
 
     EXPECT_EQ(identifier(vector<string>{"zeroth"}, 0).longer(), "<0>");
+    EXPECT_EQ(identifier(vector<string>{"<name>"}, 0).longer(), "<name>");
     EXPECT_EQ(identifier().longer(), "...");
 }