Path: csiph.com!aioe.org!.POSTED.O5hsyUvK01te0L/SZurVSQ.user.gioia.aioe.org!not-for-mail From: =?UTF-8?Q?Arne_Vajh=c3=b8j?= Newsgroups: comp.lang.java.programmer Subject: Re: Character.isIdentifierIgnorable Date: Sat, 25 Apr 2020 13:01:18 -0400 Organization: Aioe.org NNTP Server Lines: 45 Message-ID: References: NNTP-Posting-Host: O5hsyUvK01te0L/SZurVSQ.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 Content-Language: en-US X-Notice: Filtered by postfilter v. 0.9.2 Xref: csiph.com comp.lang.java.programmer:39449 On 4/25/2020 12:57 PM, Arne Vajhøj wrote: > On 4/24/2020 11:36 PM, Jeff Higgins wrote: >> On 4/24/20 10:24 PM, Arne Vajhøj wrote: >>> On 4/24/2020 8:37 PM, Jeff Higgins wrote: >>>> On 4/24/20 8:29 PM, Arne Vajhøj wrote: >>>>> I think we are in the far out corners of the language. >>>>> >>>> Well, yeah, but still. >>>> And still leaves me questioning motivation for ignorable chars. >>> >>> We would need to find someone working at SUN back in the mid 90's >>> to know. >>> >>> If I were to guess then somebody got the "smart" idea that >>> the language should not distinguish between names where >>> the difference could not be seen when type'd/cat'ed and >>> then someone else later added the \uXXXX feature. >>> >> Maybe not that far back. >> >> from JLS-3.8 for JavaSE 9 >> Two identifiers are the same only if they are identical, that is, have >> the same >> Unicode character for each letter or digit. Identifiers that have the >> same external >> appearance may yet be different. >> >> from JLS-3.8 for JavaSE 10 >> Two identifiers are the same only if, after ignoring characters that are >> ignorable, the identifiers have the same Unicode character for each >> letter >> or digit. An ignorable character is a character for which the method >> Character.isIdentifierIgnorable(int) returns true. Identifiers that >> have the >> same external appearance may yet be different. > > But Java 8 javac did ignore them?? So does Java 7 javac. Java 6 javac gives me an error when trying to create the class file, which likely means that it is not ignoring these characters. Arne