X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fpackage.html;h=c55b5cbba98f7bf2dfd6d9dc8cfdb82c1444a75b;hp=bcba1d8dfea2722512a6f6c86e6d494bf4f1f1a1;hb=2c1c0293545f3d12c23220fd05c663e6aa3f3de1;hpb=0e17670bcfa7b0fe8eb3a2cac81f4b080a09fc98 diff --git a/src/edu/berkeley/sbp/package.html b/src/edu/berkeley/sbp/package.html index bcba1d8..c55b5cb 100644 --- a/src/edu/berkeley/sbp/package.html +++ b/src/edu/berkeley/sbp/package.html @@ -1,10 +1,12 @@
-
-
- IMPORTANT:
- BE SURE TO READ THE FILE
- doc/jargon.txt FIRST!
Also, see the legend at the bottom of this page.
-
+
+
+ The public APIs in this package are stable; package-private
+ APIs and all other packages are subject to change in future
+ releases.
Be sure to read doc/jargon.txt and the description below.
+
@@ -27,5 +29,140 @@ five categories:
+ +The input that you parse is considered to be a stream of +Tokens; this stream is represented by an +Input<Token>. In order to create this Input, +you must first decide what kind of tokens you want to parse. Based on +this decision, you should then implement subclasses of Input, +Parser, and Atom for that token type. If you are +parsing characters (which you usually are), these subclasses are +provided in the edu.berkeley.sbp.chr.* package so you don't +have to write them yourself. + +
+ +You then create a grammar by instantiating objects belonging to your +subclass of Atom and forming them into sequences using +Sequence.create___() and new Union(). + +
+ +Ultimately you will wind up with an instance of Union +corresponding to the "start nonterminal" of your grammar. You can +then provide this Union to the constructor of your +Parser subclass and invoke the Parser.parse(Input) +method on the Input to be parsed. + +
+ +The result will be a Forest, which is an efficient +representation of a set of one or more trees that may share subtrees. + +
+ +If the parse was ambiguous, you can use +Forest.expand(HashSet) to expand the Forest into all the +possible trees (there is not yet a stable API for inspecting the +Forest directly). + +
+ +If the parse was not ambiguous, you can call +Forest.expand1() to return the single possible parsing as a +Tree. You would then typically use the methods of the +Tree class to examine the parse tree. + +
++Executing this code gives the following: +
+ ++If we uncomment the line in the example, the result is: +
+ +