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Jochen Theodorou edited comment on GROOVY-7772 at 3/3/16 4:21 AM: ------------------------------------------------------------------ I think I don't understand pattern number 3 actually... I would have thought you are talking about something like this:{code:Java} class X { static foo(){} } def x = new X() def m = x.&foo m.call() {code}but this does not fail, not dynamic compiled and not static compiled. The meaning of x.&y() is in all cases always x.y(), be x a class, y a static method or not and combinations of it. Which is why pattern 4 fails. What happens if we see x.&y(args...) like a method taking X and args..., for which we curry (in the Groovy sense) the first argument with x? In other words: x.&y becomes {xarg, args... -> xarg.y(args)}.curry( x ), then all cases work like before, because that is actually what we are doing (kind of). A more Java-like version would be to have {xarg, args... -> if (y is static) X.y(args) else xarg.y(args)}.curry( x ). Then all 4 cases would work. was (Author: blackdrag): I think I don't understand pattern number 3 actually... I would have thought you are talking about something like this:{code:Java} class X { static foo(){} } def x = new X() def m = x.&foo m.call() {code}but this does not fail, not dynamic compiled and not static compiled. The meaning of x.&y() is in all cases always x.y(), be x a class, y a static method or not and combinations of it. Which is why pattern 4 fails. What happens if we see x.&y(args...) like a method taking X and args..., for which we curry (in the Groovy sense) the first argument with x? In other words: x.&y becomes {xarg, args... -> xarg.y(args)}.curry(x), then all cases work like before, because that is actually what we are doing (kind of). A more Java-like version would be to have {xarg, args... -> if (y is static) X.y(args) else xarg.y(args)}.curry(x). Then all 4 cases would work. > Class.&instanceMethod had better to have same meaning of > Class::instanceMethod of Java8 > --------------------------------------------------------------------------------------- > > Key: GROOVY-7772 > URL: https://issues.apache.org/jira/browse/GROOVY-7772 > Project: Groovy > Issue Type: Improvement > Components: groovy-runtime > Affects Versions: 2.4.6 > Reporter: UEHARA Junji > Priority: Minor > > Groovy's operator .& for method is similar functionality to Java8's method > reference operator ::. > ||No.||lhs||rhs||meaing of Groovy's .& (Closure) ||meaning of java8's :: > (FunctionalInterface)|| > |1|instance|instanceMethod| { ..args -> instance.instanceMethod(args) | same > as groovy | > |2|Class|staticMethod| { ..args -> Class.staticMethod(args) | same as groovy | > |3|instance|staticMethod| ERROR groovy.lang.MissingMethodException: | Error > same as groovy (compile error) | > |4|Class|instanceMethod|error| Function<RetType,Class,Args..>, where method > instance method of Class which is declared as ```RetType > instanceMethod(Args..) {...}```. In other words it is interpreted as a > function which takes LHS Class as the first parameter which additionally > inserted to the method.)| > IMHO, i'd like to propose to change the No 4 pattern semantics of groovy > same as Java 8 's. Because: > * You can write: > {code} > ["a,b,c"].collect ( String.&toUpperCase ) > {code} > instaed of > {code} > ["a,b,c"].collect { it.toUpperCase() } > {code} > * Can have correspond operator to java8's ::. which is understandablea and > needed for Java programmers. -- This message was sent by Atlassian JIRA (v6.3.4#6332)