disclosure: I jumped to this chapter from 6th Chapter and hence

Could you please explain the 'reduce' in this example? can it have different param list - 3 instead of 2?
I tried having 3 map and one reduce with 3 params.
am getting
"Caught: groovy.lang.MissingMethodException: No signature of method: com.xyz.pcg.groovy.MapReduce$_main_closure1_closure5.doCall() is applicable for argument types: (java.lang.String, java.lang.String) values: [AAXX, BAXX]

Possible solutions: doCall(java.lang.Object, java.lang.Object, java.lang.Object), findAll(), findAll()

groovy.lang.MissingMethodException: No signature of method: com.xyz.pcg.groovy.MapReduce$_main_closure1_closure5.doCall() is applicable for argument types: (java.lang.String, java.lang.String) values: [AAXX, BAXX]

Possible solutions: doCall(java.lang.Object, java.lang.Object, java.lang.Object), findAll(), findAll()"

Message was edited by:
patb23

Listing 18.4 works fine for me as is.
Please try copying it literally into the groovy console.
Make sure you have all the line breaks right.

From your error message it looks like a line break is missing and you try to call "reduce" on a closure like

{ it ** 2}.reduce

but there needs to be a line break before the (.reduce) dot.

cheers
Dierk