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#include "error.hh"
#include "nixexpr.hh"
#include <iostream>
#include <optional>
int main()
{
using namespace nix;
// In each program where errors occur, this has to be set.
ErrorInfo::programName = std::optional("error-demo");
// 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")
// the templated value, 'warning', is automatically colored yellow.
.hint(hintfmt("there was a %1%", "warning"))
);
/*
// 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.
SymbolTable testTable;
auto problem_symbol = testTable.create("problem");
printErrorInfo(NixLangWarning()
.name("warning name")
.description("warning description")
.pos(Pos(problem_symbol, 40, 13))
.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")
.pos(Pos(problem_symbol, 40, 13))
.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;
}
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