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| From | Hans-Peter Diettrich <DrDiettrich1@netscape.net> |
| Newsgroups | comp.compilers |
| Subject | Re: FIRST_k, FOLLOW_k, k>1 |
| Date | Sat, 8 Feb 2020 11:00:48 +0100 |
| Organization | Compilers Central |
| Lines | 22 |
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| Message-ID | <20-02-007@comp.compilers> (permalink) |
| References | <20-02-004@comp.compilers> <20-02-005@comp.compilers> |
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| Keywords | parse, LL(1) |
| Posted-Date | 08 Feb 2020 09:36:36 EST |
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| Xref | csiph.com comp.compilers:2445 |
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Am 06.02.2020 um 23:16 schrieb Andy:
> I search examples,
> E->aWbXYcdZ
> W->w
> X->x
> Y->y
> Z->z
>
> if for FIRST(k=4) wil be: E={awbx} W={wbxy} X={xycd} Y={ycdz} Z={z}
> what is convention?
Your grammar definitely is LL(1). You should provide a grammar that
requires longer lookahead.
IMO the FIRST set covers all *different* sequences, in your case
FIRST(E)={a} hence LL(1).
Only if there exist multiple alternatives starting with 'a' they have to
be listed as e.g. FIRST(E)={ax, ay}.
Dunno about the FOLLOW set, perhaps it can stay LL(1)?
DoDi
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FIRST_k, FOLLOW_k, k>1 Andy <borucki.andrzej@gmail.com> - 2020-02-06 10:43 -0800
Re: FIRST_k, FOLLOW_k, k>1 Andy <borucki.andrzej@gmail.com> - 2020-02-06 14:16 -0800
Re: FIRST_k, FOLLOW_k, k>1 Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2020-02-08 11:00 +0100
Re: FIRST_k, FOLLOW_k, k>1 Andy <borucki.andrzej@gmail.com> - 2020-02-08 11:54 -0800
Re: FIRST_k, FOLLOW_k, k>1 Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2020-02-09 02:46 +0100
FIRST_k, FOLLOW_k, k>1 Christopher F Clark <christopher.f.clark@compiler-resources.com> - 2020-02-07 16:12 +0200
Re: FIRST_k, FOLLOW_k, k>1 honey crisis <gaztoast@gmail.com> - 2020-02-08 18:18 -0800
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