#include "error.hh" #include #include int main() { using namespace nix; // In each program where errors occur, this has to be set. ErrorInfo::programName = std::optional("error-test"); // There are currently four error types: // // ProgramError, ProgramWarning, NixLangError, NixLangWarning. // // Each error type is created with a specific sequence of builder functions. // Unlike with a constructor, each parameter is clearly named. // If the sequence of function calls isn't followed, then there's a type error. // This should make for a consistent look in the code when errors are created. // ProgramError takes name, description, and an optional hint. printErrorInfo( ProgramError() .name("name") .description("error description") .nohint() ); // ProgramWarning takes name, description, and an optional hint. // The hint is in the form of a hintfmt class, which wraps boost::format(), and // makes all the substituted text yellow. printErrorInfo( ProgramWarning() .name("warning name") .description("warning description") .hint(hintfmt("there was a %1%") % "warning") // 'warning' will be yellow. ); /* // some invalid errors: // type error: no hint function. ProgramError() .name("name") .description("error description"); // type error: description before name. ProgramError() .description("error description") .name("name") .nohint(); // type error: hint function with regular boost format, not special hintfmt. ProgramError() .description("error description") .name("name") .hint(format("there was a %1%") % "warning"); */ // NixLangWarning adds nix file, line number, column range, and the lines of code // where a warning occurred. printErrorInfo( NixLangWarning() .name("warning name") .description("warning description") .nixFile("myfile.nix") .lineNumber(40) .columnRange(13,7) .linesOfCode(std::nullopt ,"this is the problem line of code" ,std::nullopt) .hint(hintfmt("this hint has %1% templated %2%!!") % "yellow" % "values") ); // NixLangError is just the same as NixLangWarning, except for the Error flag. printErrorInfo( NixLangError() .name("error name") .description("error description") .nixFile("myfile.nix") .lineNumber(40) .columnRange(13,7) .linesOfCode(std::optional("previous line of code") ,"this is the problem line of code" ,std::optional("next line of code")) .hint(hintfmt("this hint has %1% templated %2%!!") % "yellow" % "values") ); return 0; }