From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: tuhs-bounces@minnie.tuhs.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id 1af9570c for ; Mon, 29 Oct 2018 19:33:34 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 5D57AA2211; Tue, 30 Oct 2018 05:33:33 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id BC0FFA1FB3; Tue, 30 Oct 2018 05:33:00 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id F04A8A1FB3; Tue, 30 Oct 2018 04:37:48 +1000 (AEST) Received: from mail-vk1-f170.google.com (mail-vk1-f170.google.com [209.85.221.170]) by minnie.tuhs.org (Postfix) with ESMTPS id 84D3BA1FB0 for ; Tue, 30 Oct 2018 04:37:43 +1000 (AEST) Received: by mail-vk1-f170.google.com with SMTP id 185so2317635vkv.13 for ; Mon, 29 Oct 2018 11:37:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=sBNZMlI12U86nMAu+kLNy8ZUonLqGAi5D6sefxT9XYQ=; b=ZyCxeYY/ZjlEB4rAJVwxxfqIWEZ8cqhJ5fxQBHns+XDrzA+huUHNse+wZQo6DW0EIL Q+s1luDXBYXy7aAbl9uFUD0Omze5LwEixd82dqgzEBIKhmU8tF0DukMIRV+7D5pQomh4 ow6ZJ74/3uGM8tVen/UdxF3bMi6+FJ21OwjoLTXEbPpb2XB3BDN0GEW8SY156F+Ou29W itSFOMW0oNkQeaweqKdhidwXhbzCjPHlc71+o688jVTgUy/BJZPUF6X/bHHlVoBlLIlr lMAMAXDtaEpiJdehwNVu1NeDyANGTSeUyYezIweu7EWCH0IpMdcoridf9NhFWBc0HpM7 ku8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=sBNZMlI12U86nMAu+kLNy8ZUonLqGAi5D6sefxT9XYQ=; b=TFbrwF4PdgzD2XfXFR+alc6+gconC79yxjIAOGZxxBOnW8fhqqayJXyd0O4MEtaNG+ BVYGrMu5vy71GIuG101AC7iQaeyJgQmG/KPlE7Vn6x3jY3xl+GOd1jQ46CYN6dZTRRPa qmBX3f2rzoviVzFgRRmuPaFzQJmWs2lCvrztZq7WVRCuUURPh0jkqazP007ehb2QZD9s b9EpdTSZvirRLTJIrsSGlizG0KbBehBAn1YlbonBoOAB1dsZIigtvj047uSChGf7eI7w mCElR25YTX+k+lYGdZCUmFyHIDzLnZmSCdki/mDNUAawqVMRhBgXFXZFqbWwP5JmT/Jt XnmQ== X-Gm-Message-State: AGRZ1gI4w1KCbApg7leXeP/iyhAD4CapuSFXMS99UPEGp23HdgK4VoY6 XCpWljkqdyPHcEBTjGzBe42S7hSgbSG/fTZ8nMh+2A== X-Google-Smtp-Source: AJdET5fZFJGpKOECRtP1M7PHdoC50R28s1LgsXWYCg4hI88c5xj3vtp/9wHYqwoRMlJrn5z5wDZLZQ+el1h8Oa659t8= X-Received: by 2002:a1f:9255:: with SMTP id u82mr6450246vkd.85.1540838262478; Mon, 29 Oct 2018 11:37:42 -0700 (PDT) MIME-Version: 1.0 References: <7wftwpi4z7.fsf@junk.nocrew.org> <068e3163f59e699e486287cf033dc226fbb59b87@webmail.yaccman.com> In-Reply-To: <068e3163f59e699e486287cf033dc226fbb59b87@webmail.yaccman.com> From: Warner Losh Date: Mon, 29 Oct 2018 12:37:31 -0600 Message-ID: To: Steve Johnson Content-Type: multipart/alternative; boundary="0000000000004ab4b30579625dc1" Subject: Re: [TUHS] Archaic yacc C grammar X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Eunuchs Hysterical Society Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --0000000000004ab4b30579625dc1 Content-Type: text/plain; charset="UTF-8" On Mon, Oct 29, 2018 at 12:30 PM Steve Johnson wrote: > We actually had a pretty good system for making changes like that. First, > we would change > the compiler to accept both the old and the new. Then we would produce a > warning > that on a particular date the old would no longer work. Then we made the > old an error > and printed a message about how to fix it. Eventually, we just let it be > a syntax error. > This process was applied many times on the way from typeless B to strongly > typed C. > How long a transition period did you typically have? Warner --0000000000004ab4b30579625dc1 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Mon= , Oct 29, 2018 at 12:30 PM Steve Johnson <scj@yaccman.com> wrote:
= We actually had a pretty good system for making changes like that.=C2=A0 Fi= rst, we would change
the compiler to accept both the old and = the new.=C2=A0=C2=A0 Then we would produce a warning
that on a pa= rticular date the old would no longer work.=C2=A0 Then we made the old an e= rror
and printed a message about how to fix it.=C2=A0=C2=A0 Event= ually, we just let it be a syntax error.
This process was applied= many times on the way from typeless B to strongly typed C.

How long a transition period did you typically= have?

Warner=C2=A0
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