Loops/Nested: Difference between revisions

Line 1,653:

=={{header|Smalltalk}}==

Notice that the original answer (see below) was wrong.

~~original text: "~~Smalltalk has no ways of escaping from loops (single or nested), even if it is possible to extend its iteration capabilities in several ways. "

Line 1,695:

exitBlock := [:exitValue | ^ exitValue].

[true] whileTrue:[ self value:exitBlock ]</lang>

in the same spirit, exits could be added to many other loop constructs. However, this is really only very rarely needed in Smalltalk, because a ^(return) out of a block returns from the enclosing method. ~~This is~~ usually used to exit early from a utility ~~method~~.

in the same spirit, exits could be added to many other loop constructs. However, this is really only very rarely needed in Smalltalk, because a ^(return) out of a block returns from the enclosing method which usually used to exit early from search utility methods.

There ~~exists~~ ~~an additional~~ valueWithExit, which can be used to get out of a block early. Using that, the tasks solution is:

There is also valueWithExit, which can be used to get out of a block early and provide an alternative value. Using that, the tasks solution is:

<lang smalltalk>|v result|

Line 1,714:

]

].

nil

] valueWithExit.

Line 1,732:

Line 1,733:

⚫

Smalltalk has no ways of escaping from loops (single or nested), even if it is possible to extend its iteration capabilities in several ways.

The following code implements a BiArray class with a method that allows iteration over the elements (by columns and then by rows) and execution of a block if a condition is true.

<lang smalltalk>"this simple implementation of a bidimensional array