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Dynamic scoping

• To: mathgroup at smc.vnet.net
• Subject: [mg129642] Dynamic scoping
• From: Daniel Huber <danielphuber at gmail.com>
• Date: Sat, 2 Feb 2013 01:15:47 -0500 (EST)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• Delivered-to: l-mathgroup@wolfram.com
• Delivered-to: mathgroup-newout@smc.vnet.net
• Delivered-to: mathgroup-newsend@smc.vnet.net

Block is supposed to be a dynamic scoping construct. Therefore, in the following, "Print" should be an undefined function. But consider:

Block[{Plus},
 t = ToString[Plus[1, 2]];
 Print[t];
 ]

The output of this is: "3" and not "Plus[1,2]" as it would be if "Print" has no defined meaning.
cheers, Daniel