4 votes 4 votes I am unable to get the basic difference between these and which one are actually parsed by a top down parser and a bottom up parser ? Theory of Computation theory-of-computation + – radha gogia asked Dec 6, 2015 radha gogia 3.0k views answer comment Share Follow See all 3 Comments See all 3 3 Comments reply monanshi commented Dec 7, 2015 reply Follow Share I know a part of the answer. LL(K), LR(K) are basically CFLs only. LL(1) is used in Top down parsers while LR(0) and LR(1) is used in bottom up parsers. 0 votes 0 votes अनुराग पाण्डेय commented Jan 8, 2016 reply Follow Share Regular Grammars & Context Free Grammars may be ambiguous or unambiguous. All Regular Grammars are also Context Free. Top-down parsers use LL(k) grammars. Bottom-up parsers use LR(k) grammars. Any ambiguous CFG can neither be LL(k) nor LR(k). So regular & context-free grammars may or may not be LL(k) or LR(k), depending upon whether they are ambiguous or not. But an unambiguous CFG need not be LL(k) always, there are more conditions that must be checked like left recursion, left factoring etc. This might be useful https://gateoverflow.in/1251/gate2007_53 7 votes 7 votes surbhijain93 commented Oct 16, 2019 reply Follow Share Also,an unambiguous CFG need not be LR(k) always. 0 votes 0 votes Please log in or register to add a comment.
