Difference between revisions of "Top-Down Parsing/Exercise 6"

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Consider the following grammar, where '''<tt>F</tt>''' is the initial symbol and '''<tt>{a,b,c,d,e}</tt>''' is the set of terminal symbols:
 
Consider the following grammar, where '''<tt>F</tt>''' is the initial symbol and '''<tt>{a,b,c,d,e}</tt>''' is the set of terminal symbols:
  
 +
O -> a
 +
G -> F c | O c d | ε
 
  F -> G b | O c F e
 
  F -> G b | O c F e
O -> a
 
G -> F c | O c d | (eps)
 
  
 
# Examine the grammar and rewrite it so that an LL(1) predictive parser can be built for the corresponding language.
 
# Examine the grammar and rewrite it so that an LL(1) predictive parser can be built for the corresponding language.
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== Solution ==
 
== Solution ==
  
=== Semantic tree and dependency graph ===
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[[Image:Top-Down Parsing-exercise-06.jpg|800px|Temporary handwritten solution]]
 
 
"x" is an inherited attribute (propagation in blue); "val" is a synthesized attribute (propagration in red).
 
 
 
Temporary handwritten solution.
 
 
 
[[Image:Top-Down Parsing/Exercise 6.png]]
 
 
 
=== Attribute grammar using only synthesized attributes ===
 
 
 
 
 
  
[[category:Teaching]]
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[[category:Compiladores]]
[[category:Compilers]]
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[[category:Ensino]]

Latest revision as of 14:59, 29 April 2024

Problem

Consider the following grammar, where F is the initial symbol and {a,b,c,d,e} is the set of terminal symbols:

O -> a
G -> F c | O c d | ε
F -> G b | O c F e
  1. Examine the grammar and rewrite it so that an LL(1) predictive parser can be built for the corresponding language.
  2. Compute the FIRST and FOLLOW sets for all non-terminal symbols in the new grammar and build the parse table.
  3. Show the analysis table (stack, input, and actions) for the parsing process of the acbe input sequence.

Solution

Temporary handwritten solution