Recursive ascent parser: Difference between revisions

Revision as of 21:29, 16 June 2009

Revision as of 10:53, 24 June 2009

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== Example ==

Consider the following grammar in [[GNU Bison | bison]] syntax:

<pre>expr : expr '+' term { $$ = $1 + $3; }

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;</pre>

This grammar is [[LR parsing#A note about LR(0) versus SLR and LALR parsing | LR(0)]] in that it is left-recursive (in the '''expr''' non-terminal) but does not require any lookahead. Recursive ascent is also capable of handling grammars which are LALR(1) in much the same way that table-driven parsers handle such cases (by pre-computing conflict resolutions based on possible lookahead).

The following is a [[Scala (programming language) | Scala]] implementation of a recursive ascent parser based on the above grammar:

<pre>object ExprParser {

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}</pre>

== See Also also==

* [[Recursive descent parser]]