Groovy Regex matcher OR - either unique groups or duplicate group ids - regex

Question

I want to regex search a string representing a log file, locate multiple potential error message, and print the result.
Example Input (single string)
...
Unable to parse YAML file: [mapping values are not allowed in this context] at line 1234\r\n
worthless line\r\n
KitchenInventory.cs(285,118): error CS2345: 'ButteryBread' does not contain a definition for 'DropOnFloor'\r\n
another worthless line\r\n
...
Each error type has certain grouping categories that I'm attempting to capture, which may or may not be present in other error types.
My goal is to output error details after doing the regex search, filling in as many values as are present in each error regex:
Error: Unable to parse YAML file
Details: mapping values are not allowed in this context
Line: 1234
Error: CS2345
Details: 'ButteryBread' does not contain a definition for 'DropOnFloor'
Filename: KitchenInventory.cs
Line: 285,118
(Notice that filename is ommited for the YAML error, due to YAML errors not containing that piece of information.
I've found that I cannot do a logical OR to create a massive Regex string, because there are duplicate grouping names. I attempted to do each regex search individually, but I receive an exception when checking for the presence of a field:
def pattern = ~patternString
def matcher = pattern.matcher(lines)
while (matcher.find()) {
if (matcher.group('filename')) {
println "Filename: "+matcher.group('filename')
}
if (matcher.group('error')) {
println "Error: "+matcher.group('error')
}
if (matcher.group('message')) {
println "Message: "+matcher.group('message')
}
}
Caught: java.lang.IllegalArgumentException: No group with name <errorCode>
java.lang.IllegalArgumentException: No group with name <errorCode>
Is there a way for me to iterate through Groovy regex group names that COULD be present, without throwing exceptions? Alternatively, am I going about this the wrong way, and is there an easier way for me to achieve my goal?

Answer 1

I was looking for the same thing and was not able to find a "groovier" way to do it.
Only solution that I found was to verify if the pattern string contains the group name:
if (stringPattern.contains('message')) {
println "Message: "+matcher.group('message')
}