camelcase; optional hint

3 files changed, 119 insertions, 57 deletions

diff --git a/src/libutil/error.cc b/src/libutil/error.cc
index 9fbd234e0..d6595070f 100644
--- a/src/libutil/error.cc
+++ b/src/libutil/error.cc
@@ -24,55 +24,55 @@ string showErrLine(ErrLine &errLine)
   };
 }
 
-void print_code_lines(string &prefix, NixCode &nix_code) 
+void printCodeLines(string &prefix, NixCode &nixCode) 
 {
   
-  if (nix_code.errLine.has_value()) 
+  if (nixCode.errLine.has_value()) 
   {
     // previous line of code.
-    if (nix_code.errLine->prevLineOfCode.has_value()) { 
+    if (nixCode.errLine->prevLineOfCode.has_value()) { 
       cout << format("%1% %|2$5d|| %3%")
         %  prefix
-        % (nix_code.errLine->lineNumber - 1)
-        % *nix_code.errLine->prevLineOfCode
+        % (nixCode.errLine->lineNumber - 1)
+        % *nixCode.errLine->prevLineOfCode
         << endl;
     }
 
     // line of code containing the error.%2$+5d%
     cout << format("%1% %|2$5d|| %3%")
       %  prefix
-      % (nix_code.errLine->lineNumber)
-      % nix_code.errLine->errLineOfCode
+      % (nixCode.errLine->lineNumber)
+      % nixCode.errLine->errLineOfCode
       << endl;
     
     // error arrows for the column range.
-    if (nix_code.errLine->columnRange.has_value()) 
+    if (nixCode.errLine->columnRange.has_value()) 
     {
-      int start = nix_code.errLine->columnRange->start;
+      int start = nixCode.errLine->columnRange->start;
       std::string spaces;
       for (int i = 0; i < start; ++i)
       {
         spaces.append(" ");
       }
 
-      int len = nix_code.errLine->columnRange->len;
+      int len = nixCode.errLine->columnRange->len;
       std::string arrows;
       for (int i = 0; i < len; ++i)
       {
         arrows.append("^");
       }
     
-      cout << format("%1%      |%2%" ANSI_RED "%3%" ANSI_NORMAL) % prefix % spaces % arrows;
+      cout << format("%1%      |%2%" ANSI_RED "%3%" ANSI_NORMAL) % prefix % spaces % arrows << endl;
     }
 
 
 
     // next line of code.
-    if (nix_code.errLine->nextLineOfCode.has_value()) { 
+    if (nixCode.errLine->nextLineOfCode.has_value()) { 
       cout << format("%1% %|2$5d|| %3%")
       %  prefix
-      % (nix_code.errLine->lineNumber + 1)
-      % *nix_code.errLine->nextLineOfCode
+      % (nixCode.errLine->lineNumber + 1)
+      % *nixCode.errLine->nextLineOfCode
       << endl;
     }
 
@@ -80,36 +80,36 @@ void print_code_lines(string &prefix, NixCode &nix_code)
     
 }
 
-void print_error(ErrorInfo &einfo) 
+void printErrorInfo(ErrorInfo &einfo) 
 {
   int errwidth = 80;
   string prefix = "  ";
 
-  string level_string;
+  string levelString;
   switch (einfo.level) 
   {
     case ErrLevel::elError: 
       {
-        level_string = ANSI_RED;
-        level_string += "error:";
-        level_string += ANSI_NORMAL;
+        levelString = ANSI_RED;
+        levelString += "error:";
+        levelString += ANSI_NORMAL;
         break;
       }
     case ErrLevel::elWarning: 
       {
-        level_string = ANSI_YELLOW;
-        level_string += "warning:";  
-        level_string += ANSI_NORMAL;
+        levelString = ANSI_YELLOW;
+        levelString += "warning:";  
+        levelString += ANSI_NORMAL;
         break;
       }
     default: 
       {
-        level_string = "wat:";  
+        levelString = "wat:";  
         break;
       }
   }
 
-  int ndl = prefix.length() + level_string.length() + 3 + einfo.name.length() + einfo.programName.value_or("").length();
+  int ndl = prefix.length() + levelString.length() + 3 + einfo.name.length() + einfo.programName.value_or("").length();
   int dashwidth = ndl > (errwidth - 3) ? 3 : 80 - ndl; 
 
   string dashes;
@@ -119,7 +119,7 @@ void print_error(ErrorInfo &einfo)
   // divider.
   cout << format("%1%%2%" ANSI_BLUE " %3% %4% %5% %6%" ANSI_NORMAL)
     % prefix
-    % level_string
+    % levelString
     % "---"
     % einfo.name
     % dashes
@@ -152,11 +152,15 @@ void print_error(ErrorInfo &einfo)
 
   // lines of code.
   if (einfo.nixCode.has_value())
-    print_code_lines(prefix, *einfo.nixCode);
+    printCodeLines(prefix, *einfo.nixCode);
 
   // hint
-  cout << prefix << einfo.hint << endl;
-  cout << prefix << endl;
+  if (einfo.hint.has_value()) 
+  {
+    cout << prefix << endl;
+    cout << prefix << *einfo.hint << endl;
+    cout << prefix << endl;
+  }
 
 }
 
diff --git a/src/libutil/error.hh b/src/libutil/error.hh
index 7260dfd5b..f02d7288a 100644
--- a/src/libutil/error.hh
+++ b/src/libutil/error.hh
@@ -1,12 +1,16 @@
 #pragma once
 
-#include "types.hh"
+#include "util.hh"
 #include <string>
 #include <optional>
 #include <iostream>
+#include <iomanip>
 
 using std::string;
 using std::optional;
+using boost::format;
+using std::cout;
+using std::endl;
 
 namespace nix {
 
@@ -81,13 +85,13 @@ class ErrorInfo {
     string name;
     string description;
     optional<NixCode> nixCode;
-    string hint;
+    optional<string> hint;
     ErrorInfo& GetEI() { return *this; }
 
     static optional<string> programName;
 
     // give these access to the private constructor, 
-    // when they are direct descendants.
+    // when they are direct descendants (children but not grandchildren).
     friend AddName<ErrorInfo>;
     friend AddDescription<ErrorInfo>;
     friend AddNixCode<ErrorInfo>;
@@ -150,7 +154,7 @@ class AddDescription : private T
 };
 
 template <class T> 
-class AddNixFile : public T
+class AddNixFile : private T
 {
   public:
     T& nixFile(string filename) { 
@@ -162,7 +166,7 @@ class AddNixFile : public T
 };
 
 template <class T> 
-class AddLineNumber : public T
+class AddLineNumber : private T
 {
   public:
     T& lineNumber(int lineNumber) { 
@@ -174,7 +178,7 @@ class AddLineNumber : public T
 };
 
 template <class T> 
-class AddColumnRange : public T
+class AddColumnRange : private T
 {
   public:
     T& columnRange(unsigned int start, unsigned int len) { 
@@ -186,7 +190,7 @@ class AddColumnRange : public T
 };
 
 template <class T> 
-class AddLOC : public T
+class AddLOC : private T
 {
   public:
     T& linesOfCode(optional<string> prevloc, string loc, optional<string> nextloc) { 
@@ -199,17 +203,64 @@ class AddLOC : public T
     ErrorInfo& GetEI() { return T::GetEI(); }
 };
 
-typedef AddNixFile<AddErrLine<NixCode>> MkNixCode;
+template <class T>
+class yellowify
+{
+public:
+    yellowify(T &s) : value(s) {}
+    T &value;
+};
+
+template <class T>
+std::ostream& operator<<(std::ostream &out, const yellowify<T> &y)
+{
+  return out << ANSI_YELLOW << y.value << ANSI_NORMAL;
+}
+
+// hint format shows templated values in yellow.
+class hintfmt 
+{
+  public:
+    hintfmt(string format) :fmt(format) {}
+    template<class T>
+      hintfmt& operator%(const T &value) { fmt % yellowify(value); return *this; }
+
+    template <typename U>
+    friend class AddHint;
+  private:
+    format fmt;
+      
+};
+
+template <class T> 
+class AddHint : private T
+{
+  public:
+    T& hint(hintfmt &hfmt) {
+      GetEI().hint = optional(hfmt.fmt.str());
+      return *this;
+    }
+    T& nohint() {
+      GetEI().hint = std::nullopt;
+      return *this;
+    }
+  protected:
+    ErrorInfo& GetEI() { return T::GetEI(); }
+};
+
+// --------------------------------------------------------
+// error types
 
-typedef AddName<AddDescription<EIError>> StandardError;
-typedef AddName<AddDescription<EIWarning>> StandardWarning;
+typedef AddName<AddDescription<AddHint<EIError>>> StandardError;
+typedef AddName<AddDescription<AddHint<EIWarning>>> StandardWarning;
 
 typedef AddName<
         AddDescription<
         AddNixFile<
         AddLineNumber<
         AddColumnRange<
-        AddLOC<EIError>>>>>> MkNixError;
+        AddLOC<
+        AddHint<EIError>>>>>>> MkNixError;
 typedef AddName<
         AddDescription<
         AddNixFile<
@@ -217,10 +268,15 @@ typedef AddName<
         AddColumnRange<
         AddLOC<EIWarning>>>>>> MkNixWarning;
 
+
+// --------------------------------------------------------
+// error printing
+
+void printErrorInfo(ErrorInfo &einfo);
+
 string showErrLine(ErrLine &errLine);
 
-void print_code_lines(string &prefix, NixCode &nix_code); 
+void printCodeLines(string &prefix, NixCode &nixCode); 
 
-void print_error(ErrorInfo &einfo);
 }
 
diff --git a/tests/errors/main.cc b/tests/errors/main.cc
index f53101629..35d2a1cdf 100644
--- a/tests/errors/main.cc
+++ b/tests/errors/main.cc
@@ -8,9 +8,9 @@ using std::nullopt;
 using std::cout;
 using std::endl;
 
-int main() {
-
-using namespace nix; 
+int main() 
+{
+  using namespace nix; 
 
   ErrorInfo::programName = optional("errorTest");
 
@@ -35,19 +35,23 @@ using namespace nix;
   generic.program = "nixtool.exe";
   generic.nixCode = nixcode;
 
-  print_error(generic);
+  printErrorInfo(generic);
   */
 
-  print_error(StandardError()
+  printErrorInfo(StandardError()
                 .name("name")
-                .description("description"));
+                .description("description")
+                .nohint()
+                );
 
-  print_error(StandardWarning()
+  printErrorInfo(StandardWarning()
                 .name("warning name")
-                .description("warning description"));
+                .description("warning description")
+                .nohint()
+                );
 
 
-  print_error(MkNixWarning()
+  printErrorInfo(MkNixWarning()
                 .name("warning name")
                 .description("warning description")
                 .nixFile("myfile.nix")
@@ -57,19 +61,17 @@ using namespace nix;
                             ,"this is the problem line of code"
                             ,nullopt));
 
-  print_error(MkNixError()
+  printErrorInfo(MkNixError()
                 .name("error name")
                 .description("error description")
                 .nixFile("myfile.nix")
                 .lineNumber(40)
                 .columnRange(13,7)
-                .linesOfCode(nullopt
+                .linesOfCode(optional("previous line of code")
                             ,"this is the problem line of code"
-                            ,nullopt));
+                            ,optional("next line of code"))
+                .hint(hintfmt("this hint has %1% templated %2%!!") % "yellow" % "values")
+                );
 
   return 0;
 }
-
-
-
-