From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,9a0ff0bffdf63657 X-Google-Attributes: gidfac41,public X-Google-Thread: f43e6,9a0ff0bffdf63657 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,4b06f8f15f01a568 X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,9a0ff0bffdf63657 X-Google-Attributes: gid1108a1,public From: Patrick Logan Subject: Re: Software landmines (loops) Date: 1998/09/08 Message-ID: #1/1 X-Deja-AN: 389181832 References: <35F56A3B.8DEA51A7@draper.com> Organization: Teleport - Portland's Public Access (503) 220-1016 NNTP-Posting-Date: Tue, 08 Sep 1998 15:19:24 PDT Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.lang.ada Date: 1998-09-08T00:00:00+00:00 List-Id: In comp.object Patrick Doyle wrote: : An if-then-else statement can have multiple returns: : if a = 1 then : ... : elseif a = 2 then : ... : elseif a = 3 then : ... : end : Each "elseif" is an exit from this block of code, as is the "end". : How does this figure into the se/se picture? This is the definitions of IF/ELSE. The rationale is that there are several blocks of code, but only *one* will execute. That one block itself has a single entry and exit. BTW the cutest thing about Smalltalk is that IF/ELSE is implemented using the single entry/exit form you are alluding to above. In Smalltalk, True is a class and False is a class. Both inherit from Boolean. True>>ifTrue: trueBlock ifFalse: falseBlock ^trueBlock value False>>ifTrue: trueBlock ifFalse: falseBlock ^falseBlock value So in this case IF/ELSE is implemented in a "pure" SE/SE fashion! 8^) -- Patrick Logan (H) mailto:plogan@teleport.com (W) mailto:patrickl@gemstone.com http://www.gemstone.com