[#XTENLANG-55] "incompatible types" using the next() function of an Iterator - jira.codehaus.org

class C {}

class Bug {

    def foo(it:Iterator[C]) {
        val c:C = it.next();
    }
}

x10c: classes\Bug.java:90: incompatible types
found : java.lang.Object
required: C
/* } */).next();
^
1 error

Workaround: use for (...) syntax where possible; if not possible add a cast: it.next() as C.

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Bruce Lucas made changes - 25/Sep/08 1:37 PM

Field	Original Value	New Value
Summary	handling of Iterator is broken	"incompatible types" using the next() function of an Iterator
Priority	Blocker [ 1 ]	Major [ 3 ]
Description	{code} class C {} class Bug { def foo(it:Iterator[C]) { val c:C = it.next(); } } {code} x10c: classes\Bug.java:90: incompatible types found : java.lang.Object required: C /* } */).next(); ^ 1 error If we change the definition of x10.lang.Iterator to not have a NativeRep of java.util.Iterator the preceding code works, but I imagine this would break X10 library code written in Java that implements Iterators, and then also the following code breaks: \\ \\ {code} class C {} class D { incomplete def iterator(): Iterator[C]; } class Bug { def bar(d:D) { for (c:C in d); } } {code} x10c: classes\Bug.java:82: incompatible types found : x10.lang.Iterator<capture of ? extends C> required: java.util.Iterator for (java.util.Iterator c__ = (d).iterator(); c__.hasNext(); ) { ^ Note: Some input files use unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 error	{code} class C {} class Bug { def foo(it:Iterator[C]) { val c:C = it.next(); } } {code} x10c: classes\Bug.java:90: incompatible types found : java.lang.Object required: C /* } */).next(); ^ 1 error Workaround: use for (...) syntax where possible; if not possible add a cast: it.next() as C.

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Bruce Lucas added a comment - 21/Oct/08 7:53 AM

Appears to have been fixed (per daily test run)

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Bruce Lucas added a comment - 21/Oct/08 7:53 AM Appears to have been fixed (per daily test run)

Bruce Lucas made changes - 21/Oct/08 7:53 AM

Resolution		Fixed [ 1 ]
Status	Open [ 1 ]	Closed [ 6 ]

"incompatible types" using the next() function of an Iterator