[GROOVY-712] Closures do not localize variables.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0-beta-9
• Fix Version/s: 1.0-JSR-2
• Environment: Win XP, JDK 5.0_01
• Assignee: Jochen Theodorou
• Reporter: Andrew Grande
• Created: 28/Jan/05 01:16
• Updated: 14/Jun/05 08:34
• Resolved: 14/Jun/05 08:34

Description

images.each { img |
print "Downloading image #${index}...";
imgResp = wc.getResponse(img.request);
println "Ok";

filename = "images/report${index}.png";
print "Saving image to ${filename}...";
new File(filename).withOutputStream { os |
imgResp.inputStream.eachByte

{ b | os.write(b.toInteger()) }

;
}
println "Ok";

...

index++;
}

// save html
filename = "bug-report.html";

==================
The var in question is filename (in closure and at the very end). If the code is run as is, it fails after 'Downloading image...' message (image is downloaded) with a NullPointerException. Very misleading. If the last line is removed everything is fine.

I saw a 'feature' of closures providing a kind of pointers to local variables. While this may be useful at times, if your target is be Java-like, this case feels very very unnatural. Besides, the failure message and the place it fails at make you scratch your head without no idea.