Parser - Revision history

5.135.180.216: rDjkjA nhkwtyzftmkq, [url=http://qtnuzragqhqb.com/]qtnuzragqhqb[/url], [link=http://jpbdficaynzd.com/]jpbdficaynzd[/link], http://ydowpikexhpp.com/

2013-06-10T15:21:25Z

rDjkjA <a href="http://nhkwtyzftmkq.com/">nhkwtyzftmkq</a>, [url=http://qtnuzragqhqb.com/]qtnuzragqhqb[/url], [link=http://jpbdficaynzd.com/]jpbdficaynzd[/link], http://ydowpikexhpp.com/

Admin: /* Examples of bottom-up parsers */

2012-12-10T22:53:33Z

‎Examples of bottom-up parsers

Admin at 17:11, 2 December 2012

2012-12-02T17:11:30Z

Admin: /* Examples of bottom-up parsers */

2012-11-24T19:19:41Z

‎Examples of bottom-up parsers

Admin: /* Examples of top-down parsers: */

2012-11-24T19:19:27Z

‎Examples of top-down parsers:

Admin: /* Bottom-up parsing */

2012-11-24T19:19:19Z

‎Bottom-up parsing

Admin: /* Bottom-up parsing */

2012-11-24T19:19:10Z

‎Bottom-up parsing

Admin: /* Top-down parsing */

2012-11-24T19:18:55Z

‎Top-down parsing

Admin: Created page with "Strictly speaking, '''parser''' is something that separates data into more easily understood chunks. More practically, a parser is the part of a compiler that goes through a p..."

2012-11-24T19:18:36Z

Created page with "Strictly speaking, '''parser''' is something that separates data into more easily understood chunks. More practically, a parser is the part of a compiler that goes through a p..."

New page

Strictly speaking, '''parser''' is something that separates data into more easily understood chunks. More practically, a parser is the part of a compiler that goes through a program and cuts it into identifiable chunks before translation. Assuming that a parser is written reliably, if the parser cannot parse a program then the program contains syntax errors. Also, we can say that a parser is an algorithm or program to determine the syntactic structure of a sentence or string of symbols in some language. A parser normally takes as input a sequence of tokens output by a lexical analyser and the grammar that defines language under consideration. It may produce some kind of abstract syntax tree as output. One of the best known parser generators is yacc[INSERIR LINK].
 

The task of the parser to determine if and how the input can be derived from the start symbol within the rules of the formal grammar can be done in essentially two ways:
 

== Top-down parsing ==
A parser can start with the start symbol and try to transform it to the input. Intuitively, the parser starts from the largest elements and breaks them down into incrementally smaller parts.
Examples of top-down parsers:
* LL parsers
* Recursive descent parser
* Packrat parser
* Unger parser

== Bottom-up parsing ==
A parser can start with the input and attempt to rewrite it to the start symbol.
Intuitively, the parser attempts to locate the most basic elements, then the elements containing these, and so on.
 

Examples of bottom-up parsers:
* BC (bounded context) parsing
* Canonical LR parser
* CYK parser
* Earley parser
* GLR parser
* LALR parser
* LR parsers
* Precedence parsing
* SLR parser
 

Another term used for this type of parser is '''Shift-Reduce''' parsing.
 

'''See also:''' [http://eplmediawiki.di.uminho.pt/index.php/LALR_Parsers| LALR parsers],
[http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers| LL(k) ---- LL(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(0)_----_SLR(1)_Parsers| LR(0) ---- SLR(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers| LR(k) ---- LR(1) Parsers] and [http://eplmediawiki.di.uminho.pt/index.php/LR_vs._LL_Parsers| LR vs. LL Parsers]

@@ Line 34: / Line 34: @@
 <br><br>
-'''See also:''' [http://eplmediawiki.di.uminho.pt/index.php/LALR_Parsers| LALR parsers],
+'''See also:''' [http://eplmediawiki.di.uminho.pt/index.php/LALR_Parsers LALR parsers],
-[http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers| LL(k) ---- LL(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(0)_----_SLR(1)_Parsers| LR(0) ---- SLR(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers| LR(k) ---- LR(1) Parsers] and [http://eplmediawiki.di.uminho.pt/index.php/LR_vs._LL_Parsers| LR vs. LL Parsers]
+[http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers LL(k) ---- LL(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(0)_----_SLR(1)_Parsers LR(0) ---- SLR(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers LR(k) ---- LR(1) Parsers] and [http://eplmediawiki.di.uminho.pt/index.php/LR_vs._LL_Parsers LR vs. LL Parsers]
 [[Category:Basic Concepts]]

← Older revision		Revision as of 17:11, 2 December 2012
Line 36:		Line 36:
	'''See also:''' [http://eplmediawiki.di.uminho.pt/index.php/LALR_Parsers\| LALR parsers],		'''See also:''' [http://eplmediawiki.di.uminho.pt/index.php/LALR_Parsers\| LALR parsers],
	[http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers\| LL(k) ---- LL(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(0)_----_SLR(1)_Parsers\| LR(0) ---- SLR(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers\| LR(k) ---- LR(1) Parsers] and [http://eplmediawiki.di.uminho.pt/index.php/LR_vs._LL_Parsers\| LR vs. LL Parsers]		[http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers\| LL(k) ---- LL(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(0)_----_SLR(1)_Parsers\| LR(0) ---- SLR(1) Parsers], [http://eplmediawiki.di.uminho.pt/index.php/LR(k)_----_LR(1)_Parsers\| LR(k) ---- LR(1) Parsers] and [http://eplmediawiki.di.uminho.pt/index.php/LR_vs._LL_Parsers\| LR vs. LL Parsers]
		+
		+	[[Category:Basic Concepts]]

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 <br><br>
-=== Examples of bottom-up parsers: ===
+=== Examples of bottom-up parsers ===
 * BC (bounded context) parsing
 * Canonical LR parser

@@ Line 5: / Line 5: @@
 <br><br>
-== Top-down parsing ==
+rDjkjA  <a href="http://nhkwtyzftmkq.com/">nhkwtyzftmkq</a>, [url=http://qtnuzragqhqb.com/]qtnuzragqhqb[/url], [link=http://jpbdficaynzd.com/]jpbdficaynzd[/link], http://ydowpikexhpp.com/
-A parser can start with the start symbol and try to transform it to the input. Intuitively, the parser starts from the largest elements and breaks them down into incrementally smaller parts.
-−
-=== Examples of top-down parsers ===
-* LL parsers
-* Recursive descent parser
-* Packrat parser
-* Unger parser
 == Bottom-up parsing ==

@@ Line 30: / Line 30: @@
 * SLR parser
 <br><br>
 Another term used for this type of parser is '''Shift-Reduce''' parsing.