'is' is a method on every object in Groovy, it's used as identity operation.
a == b, maps to a.equals(b) in Java a.is(b), maps to a == b in Java. Your code is translating into: check(cond).is(true). I'm not sure why Groovy doesn't find the "is" closure on your map before it finds the built-in "is", though, unless Groovy treats "is" as a special case. However, considering that "is" is a foundational concept of Groovy, you might not want to overload it anyway, unless you are trying not to expose "Groovy" to your DSL. Jason -----Original Message----- From: Marc Paquette [mailto:mar...@mac.com] Sent: Tuesday, October 27, 2015 11:17 PM To: users@groovy.incubator.apache.org Subject: Problem using 'is' in a command chain Playing with DSL here (going through chapter 19 of « Groovy In Action, second edition », well worth the read). It seems that one cannot use the word ‘is’ to build a command chain dsl, but ‘IS’ or ‘Is’ or ‘iS’ are ok… Or is it something I’m doing wrong ? ``` [marcpa@MarcPaquette dsl]$ groovy --version Groovy Version: 2.4.3 JVM: 1.8.0_60 Vendor: Oracle Corporation OS: Mac OS X [marcpa@MarcPaquette dsl]$ cat chainWithLowerCaseIsFails.groovy def check(condition) { [is: { bool -> println "checking if $condition yields $bool, with 'is'" }, IS: { bool -> println "checking if $condition yields $bool, with 'IS'" }] } cond = (1<2) check cond is true check cond IS true [marcpa@MarcPaquette dsl]$ groovy chainWithLowerCaseIsFails.groovy checking if true yields true, with 'IS' [marcpa@MarcPaquette dsl]$ ``` Marc Paquette ---------------------------------------------------------------------- This email message and any attachments are for the sole use of the intended recipient(s). Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message and any attachments.
