Line and column numbers for syntax errors

[kyleconroy]

When parsing a invalid query, Parse returns an error string starting with "syntax error ...". Would it be possible to get the offset of the syntax error, similar to SyntaxError type in the json package?

Thanks again for the awesome package :) I'm using it to power my new project https://github.com/kyleconroy/sqlc

[Davincible]

Would be really nice to get this working. Then the results can be used as LSP

[StevenACoffman]

@kyleconroy The parser.Error type has an Error() method that only includes the message, but that same parser.Error type has all the other fields public.

• https://github.com/pganalyze/pg_query_go/blob/main/parser/parser.go#LL106C15-L106C38
  Appears to call:

• pg_query_go/parser/pg_query_parse.c

  Line 110 in 7986455

  PgQueryProtobufParseResult pg_query_parse_protobuf(const char* input)

• Appears to call:
  

  pg_query_go/parser/pg_query_parse.c

  Line 110 in 7986455

  PgQueryProtobufParseResult pg_query_parse_protobuf(const char* input)

So it looks like a PgQueryError error has:

		error = malloc(sizeof(PgQueryError));
		error->message   = strdup(error_data->message);
		error->filename  = strdup(error_data->filename);
		error->funcname  = strdup(error_data->funcname);
		error->context   = NULL;
		error->lineno    = error_data->lineno;
		error->cursorpos = error_data->cursorpos;

		result.error = error;	

Which then is read by

func newPgQueryError(errC *C.PgQueryError) *Error {
	err := &Error{
		Message:   C.GoString(errC.message),
		Lineno:    int(errC.lineno),
		Cursorpos: int(errC.cursorpos),
	}
	if errC.funcname != nil {
		err.Funcname = C.GoString(errC.funcname)
	}
	if errC.filename != nil {
		err.Filename = C.GoString(errC.filename)
	}
	if errC.context != nil {
		err.Context = C.GoString(errC.context)
	}
	return err
}

So the parser.Error should be fully populated:

type Error struct {
	Message   string // exception message
	Funcname  string // source function of exception (e.g. SearchSysCache)
	Filename  string // source of exception (e.g. parse.l)
	Lineno    int    // source of exception (e.g. 104)
	Cursorpos int    // char in query at which exception occurred
	Context   string // additional context (optional, can be NULL)
}

[StevenACoffman]

I believe #76 fixes this issue and this issue can now be closed, unless you are waiting until this is part of a release (as v4.2.0 from Feb 8 does not contain this change from Mar 10 ).

By the way, thanks very much for this work! This is very much appreciated, as is the rest of your extremely useful library!

[lfittl]

@StevenACoffman Good catch - yes, I think this can be closed. I'm in the process of doing a 4.2.1 release, so this should also be officially released soon.