A missing case in a switch causes an obscure error message

[emmebi]

Describe the bug
When a macro encounters an unhandled switch case, it produces an obscure error message which doesn't explain the source of the error

To Reproduce
Steps to reproduce the behavior:

1. create a new macro
2. add the following code:

[h: m = 2]
[switch(m):
case 1: x = 2
]

1. run the macro

The output is something like

"line 1:8: unexpected char: ':' " 

Expected behavior
A proper error message explaining the missing case

Screenshots
None

MapTool Info

• Version: 1.6.x
• Install: New

Desktop (please complete the following information):

• OS: Windows
• Version 10

[Phergus]

Tested switch statement without Default and uncaught case.

[h: m = 2][h: x = -1]
[h, switch(m):
  case 1: x = 2;
  case 3: x = 3;
]
[r: x]

now produces

SWITCH option found no match for "2".
       Statement options (if any): h, switch(m)
       Statement Body : case 1: x = 2; case 3: x = 3;