Report better error when single-quotes in program

[dandv]

I've spend over 10 minutes trying to simply pretty-print a json file on Windows. This really shouldn't be that hard, but it is because classic conventions are violated:

type file.json | jq '.'
jq '.' < file.json

both fail with a cryptic error message,

error: syntax error, unexpected INVALID_CHARACTER, expecting $end
'.'1 compile error                                               

See #392 (comment) for details.

[nicowilliams]

@dandv The problem is the shell, not jq. The problem here is that the shell doesn't handle single quotes like a Unix shell: it passes the single quotes to jq, and since single quotes are not a normal part of a jq program, you get an error. I think we could add some rules to the parser to produce an error message that might help the user understand.

Anyways, jq . (no single quotes) works on Windows.

[nicowilliams]

If you don't mind I changed the issue title as I want to use this as the vehicle for the improvement at hand.

[nicowilliams]

And, actually, I think we should probably always print a message about shell quoting when the error involves unexpected INVALID_CHARACTER, expecting $end.

[nicowilliams]

And you're right, we could probably use a larger section on the shells.

[nicowilliams]

The docs do have a note about invoking jq on Windows, right in the "Invoking jq" section. The "Note:" is not loud enough though :(

[dandv]

Thanks @nicowilliams, omitting the quotes worked. I should've tried double quotes too, which also works.