From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_MESSAGE,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 18112 invoked from network); 1 Feb 2021 04:25:18 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 1 Feb 2021 04:25:18 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 7746D9C9DD; Mon, 1 Feb 2021 14:25:13 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 7AEE69B9F8; Mon, 1 Feb 2021 14:24:33 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=dartmouth.edu header.i=@dartmouth.edu header.b="GpUjix9R"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 9DEED9B9F8; Mon, 1 Feb 2021 14:24:29 +1000 (AEST) Received: from mail-wr1-f46.google.com (mail-wr1-f46.google.com [209.85.221.46]) by minnie.tuhs.org (Postfix) with ESMTPS id C56209B9E1 for ; Mon, 1 Feb 2021 14:24:23 +1000 (AEST) Received: by mail-wr1-f46.google.com with SMTP id g10so15083451wrx.1 for ; Sun, 31 Jan 2021 20:24:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dartmouth.edu; s=google1; h=mime-version:from:date:message-id:subject:to; bh=/hzRpfz9/mG/MQUaujD3F5UMiXCLWxxWhuIqh3UNsmI=; b=GpUjix9Racf85/OpIQRP1ijgovG3YciJAEOqMt0gYBLd4T3NU/U+1VKmP59cHQKtwD 1o4f9HFvAu4AGd8gx2Mq4POi4g3/sEWWav77ODFOLfoiUFC0R5ceF4zAMP3FuBbInH/M hnjXPqQycmmPChitkarsOQafxEAb8q+3pnjAVKNdG65fALUhU1RGSfUqZw7PrcTyKO/d 5GRIio77/F50BdzryFdNhyI/4QEqm0QZz3v/cPCXC2MRvcqeiHKsCO4cRw2y0bJ63xnj 6IAansiiHJN2TZYZQxQIP53El0ZAT31QxaGl7FjKJv6B0D2ctBOL4uvKeojs/ytOJ9Ph k4Jg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=/hzRpfz9/mG/MQUaujD3F5UMiXCLWxxWhuIqh3UNsmI=; b=dAHEiL+tfa4o50vjpzFG/0GNa0ib0fxgmDbmnVWEQRZ0TTDEmUJTpgfGooUCXcCP6u G86hb02YnZos/twGPM7l7HH3cU5qECx0bN3ToDMqr7A4vP5wqEjAB/bdqTavbqhLr710 6CeQACrFO5fStToiEwG52tjQY7gUQ0im/LfHHB/t1+OMCqKA8wsyNaxGTPYVEPKEVvyo JdYQflJCehFI6KQecsWpH3Z5cQmLG4FGGClf/8z38O6Lbz8N/sgteexSVsoMi1avOS82 sFER33dVIY066QGrwrEL9tglLKOy/pjF+Zp6TZPzoFpqyaQ4iVSO9SrTpMx/pe6kTmY2 O8Fg== X-Gm-Message-State: AOAM5329NfsS/CXeLHM2u+ypzd8VUmri5XMe4YzUY3IXGLok4hy5KglT VvQXcyW3h/c0PmBTRlkspc+6f88Y4Ic87HVfbikNElg/Qful/g== X-Google-Smtp-Source: ABdhPJwWvAg8RkkdNBEm9IL6sLgXLj6L68iK2zc2/9IpB0K0Z9rR7d83vrKpfJPfFYeYX0AdSz2bDqt0Qg9JEIeydDQ= X-Received: by 2002:a5d:4a0d:: with SMTP id m13mr16071711wrq.395.1612153461989; Sun, 31 Jan 2021 20:24:21 -0800 (PST) MIME-Version: 1.0 From: M Douglas McIlroy Date: Sun, 31 Jan 2021 23:24:05 -0500 Message-ID: To: tuhs@minnie.tuhs.org Content-Type: multipart/alternative; boundary="0000000000006cf59505ba3eba97" Subject: [TUHS] [TUHS} Qed vs ed X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --0000000000006cf59505ba3eba97 Content-Type: text/plain; charset="UTF-8" > fairly early in PDP-11 development ed gained three features: & in the > rhs of substitutions plus k and t commands. (I'm not sure about & .... Oh, and backreferencing, which took regular expressions way up the complexity hierarchy--into NP-complete territory were it not for the limit of 9 backreferenced substrings. (Proof hint: reduce the knapsack problem to an ed regex.) Also g and s were generalized to allow escaped newlines. I was indeed wrong about &. It was in v1. Doug --0000000000006cf59505ba3eba97 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
> fairly early in PDP= -11 development ed gained three features: & in the
> rhs of subst= itutions plus k and t commands.=C2=A0 (I'm not sure about & ....

Oh, and backreferencing, which took = regular expressions way up the complexity hierarchy--into NP-complete terri= tory were it not for the limit of 9 backreferenced=C2=A0substrings. (Proof = hint: reduce the knapsack problem to an ed regex.)

Also g and s were generalized to allow escaped newlines.

I was indeed wrong about &. It was in v1.

<= div>Doug
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