Package com.google.javascript.jscomp.parsing.parser

Class Parser

java.lang.Object

com.google.javascript.jscomp.parsing.parser.Parser

public class Parser
extends Object

Parses a javascript file.

The various parseX() methods never return null - even when parse errors are encountered. Typically parseX() will return a XTree ParseTree. Each ParseTree that is created includes its source location. The typical pattern for a parseX() method is:

 XTree parseX() {
   SourcePosition start = getTreeStartLocation();
   parse X grammar element and its children
   return new XTree(getTreeLocation(start), children);
 }
 

parseX() methods must consume at least 1 token - even in error cases. This prevents infinite loops in the parser.

Many parseX() methods are matched by a 'boolean peekX()' method which will return true if the beginning of an X appears at the current location. There are also peek() methods which examine the next token. peek() methods must not consume any tokens.

The eat() method consumes a token and reports an error if the consumed token is not of the expected type. The eatOpt() methods consume the next token iff the next token is of the expected type and return the consumed token or null if no token was consumed.

When parse errors are encountered, an error should be reported and the parse should return a best guess at the current parse tree.

When parsing lists, the preferred pattern is:

   eat(LIST_START);
   ImmutableList.Builder<ParseTree> elements = ImmutableList.builder();
   while (peekListElement()) {
     elements.add(parseListElement());
   }
   eat(LIST_END);
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Parser.Config

Constructor Summary

Constructors

Constructor	Description
Parser(Parser.Config config, ErrorReporter errorReporter, SourceFile source)

Method Summary

Modifier and Type	Method	Description
List<Comment>	getComments()
FeatureSet	getFeatures()
@Nullable String	getSourceMapURL()	Returns the url provided by the sourceMappingURL if any was found.
@Nullable ProgramTree	parseProgram()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Parser

public Parser(Parser.Config config,
 ErrorReporter errorReporter,
 SourceFile source)

Method Details

getComments

public List<Comment> getComments()

getFeatures

public FeatureSet getFeatures()

getSourceMapURL

public @Nullable String getSourceMapURL()

Returns the url provided by the sourceMappingURL if any was found.

parseProgram

public @Nullable ProgramTree parseProgram()