Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site watmath.UUCP Path: utzoo!watmath!idallen From: idallen@watmath.UUCP Newsgroups: net.cog-eng,net.unix Subject: Re: name=value or -n value? (Visual Ambiguity) Message-ID: <7343@watmath.UUCP> Date: Fri, 23-Mar-84 00:59:57 EST Article-I.D.: watmath.7343 Posted: Fri Mar 23 00:59:57 1984 Date-Received: Fri, 23-Mar-84 21:29:49 EST References: <44@circe.UUCP> Organization: U of Waterloo, Ontario Lines: 28 Here's one reason I prefer "name=value" over "-name value". A command that looks like: bleen -name value1 value2 is syntactically ambiguous. You have to "know" whether "-name" does or does not take a following "value1" parameter. This means you have to know the semantic behaviour of the "-name" flag to know whether BLEEN is receiving both VALUE1 and VALUE2. It also means the potential for error is greater with "-name value", since the "-name" might eat up one of the otherwise independent arguments if someone thinks it doesn't take a following parameter. This syntax ambiguity isn't present with the syntax form: bleen name=value1 value2 I need know nothing about any of the parameters to tell that BLEEN is receiving only one unflagged parameter: VALUE2. Since there is no ambiguity, I can't accidentally create a semantically meaningful command if I misunderstand the behaviour of "name=". If "name" doesn't take a parameter, then "name=value" would be flagged as an error. If "name" does take a parameter, and I try to use it without one, this would again be flagged as an error. With "-name value", the program can't tell. I prefer the syntactic un-ambiguity. -- -IAN! (Ian! D. Allen) University of Waterloo