Bottom-Up Parsing/LALR(1) Example 1: Difference between revisions
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Consider the following grammar | Consider the following grammar ('''A''' is the start symbol): | ||
A → C x A | ε | |||
A | B → x C y | x C | ||
B | C → x B x | z | ||
C | |||
# Build the LALR(1) parser table. If conflicts exist, assume YACC's behavior. | # Build the LALR(1) parser table. If conflicts exist, assume YACC's behavior. | ||
| Line 11: | Line 9: | ||
# Show the stack and input states, as well as the parser actions, for the sequence '''xxzxx'''. | # Show the stack and input states, as well as the parser actions, for the sequence '''xxzxx'''. | ||
* [ | * [https://www.hlt.inesc-id.pt/~david/ist/docencia/compiladores/2007-2008/lalr-ex-1.pdf Solution]<br/>There is a "bug" in this solution: in the compacted table, L3 in state 10 should be in the column corresponding to '''y''' (corresponding to the shift to state 11 in the uncompacted table). | ||
[[category: | [[category:Compiladores]] | ||
[[category: | [[category:Ensino]] | ||
Latest revision as of 09:35, 2 May 2024
Consider the following grammar (A is the start symbol):
A → C x A | ε B → x C y | x C C → x B x | z
- Build the LALR(1) parser table. If conflicts exist, assume YACC's behavior.
- Show the differences to LR(0) and SLR(1) parsers.
- Compact the parse table, eliminating and propagating reductions.
- Show the stack and input states, as well as the parser actions, for the sequence xxzxx.
- Solution
There is a "bug" in this solution: in the compacted table, L3 in state 10 should be in the column corresponding to y (corresponding to the shift to state 11 in the uncompacted table).