lang: Parser identifies incorrect location when I assume 'else if' is a thing

[jordansissel]

mgmt reports a syntax error at the wrong location, though I believe the error itself is correct.

My error, trying to use 'else if' (I didn't realize it wasn't a thing in mcl)

It reports "unexpected IF, expecting OPEN_CURLY" -- This seems correct

However, it reports the error at line 3 pos 19, which is the first "if" and position is the {

The actual error (imo) is in "else if $foo ..." where the "if" is unexpected.

mcl:

$foo = "bar"
if $foo == "test" {
  # hmm
} else if $foo == "bar" {
  # wheee
}

Running:

../mgmt/mgmt run lang --only-unify test.mcl
This is: mgmt, version: 1.0.2-172-g7d335d04                                                                                                      
Copyright (C) James Shubin and the project contributors
Written by James Shubin <james@shubin.ca> and the project contributors
12:15:18 main: start: 1779650118977310824
12:15:18 cli: lang: lexing/parsing...
12:15:18 main: goodbye!
cli parse error: could not generate AST: parser: `syntax error: unexpected IF, expecting OPEN_CURLY` @3:19

To highlight:

$foo = "bar"

if $foo == "test" {
                  ^- This is line 3 position 19
  # hmm
} else if $foo == "bar" {
       ^ This is line 5, position 8, the real error.
  # wheee
}

[purpleidea]

Thank you for the report! I do agree the location reported is not helpful. I wonder if this is parser weirdness that can be improved easily or not. I'll try to have a look!

As an aside:

1. We haven't added the ^---- location type stuff for parser errors yet. I was hoping to try and tackle that at some point which would also make these errors easier to test too.

2. We don't have else if but it could be added. I held off because I wasn't especially convinced it's needed, but if you do find some code that you think isn't idiomatic without it, please let me know and I'll see what is missing!