Interface TokenStream

All Known Implementing Classes:

TokenStreamImpl

public interface TokenStream

An interface that allows for peeking and consuming a stream of Tokens.

Method Summary

Modifier and Type	Method	Description
Location	location()
Token	peek()
boolean	peek(String suspected)
int	peek(String... suspected)	Checks whether the value of the next token equals any of the suspected; does not consume the next token.
boolean	peek(TokenType suspected)
int	peek(TokenType... suspected)	Checks whether the type of the next token is any of the suspected; does not consume the next token.
Token	peekNextButOne()
boolean	peekNextButOne(String suspected)
boolean	peekRead(String suspected)	Checks whether the value of the next token equals the suspected; if so, consumes the token.
int	peekRead(String... suspected)	Checks whether the value of the next token is one of the suspected; if so, consumes the token.
String	peekRead(TokenType suspected)	Checks whether the type of the next token is the suspected; if so, consumes the token.
int	peekRead(TokenType... suspected)	Checks whether the type of the next token is one of the suspected; if so, consumes the token.
Token	read()
void	read(String expected)	Verifies that the value of the next token equals expected, and consumes the token.
int	read(String... expected)	Verifies that the value of the next token equals one of the expected, and consumes the token.
String	read(TokenType expected)	Verifies that the type of the next token is the expected, and consumes the token.
int	read(TokenType... expected)	Verifies that the type of the next token is one of the expected, and consumes the token.
void	setWarningHandler(WarningHandler warningHandler)	By default, warnings are discarded, but an application my install a WarningHandler.

Method Details

peek

Token peek()
    throws CompileException,
IOException

Returns:

The next token, but does not consume it

Throws:

CompileException

IOException

peek

boolean peek(String suspected)
      throws CompileException,
IOException

Returns:

Whether the value of the next token equals suspected; does not consume the next token

Throws:

CompileException

IOException

peek

int peek(String... suspected)
  throws CompileException,
IOException

Checks whether the value of the next token equals any of the suspected; does not consume the next token.

Returns:

The index of the first of the suspected that equals the value of the next token, or -1 if the value of the next token equals none of the suspected

Throws:

CompileException

IOException

peek

boolean peek(TokenType suspected)
      throws CompileException,
IOException

Returns:

Whether the type of the next token is suspected

Throws:

CompileException

IOException

peek

int peek(TokenType... suspected)
  throws CompileException,
IOException

Checks whether the type of the next token is any of the suspected; does not consume the next token.

Returns:

The index of the first of the suspected types that is the next token's type, or -1 if the type of the next token is none of the suspected types

Throws:

CompileException

IOException

peekNextButOne

Token peekNextButOne()
              throws CompileException,
IOException

Returns:

The next-but-one token, but consumes neither the next nor the next-but-one token

Throws:

CompileException

IOException

peekNextButOne

boolean peekNextButOne(String suspected)
                throws CompileException,
IOException

Returns:

Whether the value of the next-but-one token equals the suspected; consumes neither the next nor the next-but-one token

Throws:

CompileException

IOException

read

Token read()
    throws CompileException,
IOException

Returns:

The next token, which it also consumes, or null iff the scanner is at end-of-input

Throws:

CompileException

IOException

read

void read(String expected)
   throws CompileException,
IOException

Verifies that the value of the next token equals expected, and consumes the token.

Throws:

CompileException - The value of the next token does not equal expected (this includes the case that the scanner is at end-of-input)

IOException

read

int read(String... expected)
  throws CompileException,
IOException

Verifies that the value of the next token equals one of the expected, and consumes the token.

Returns:

The index of the consumed token within expected

Throws:

CompileException - The value of the next token does not equal any of the expected (this includes the case where the scanner is at end-of-input)

IOException

read

String read(TokenType expected)
     throws CompileException,
IOException

Verifies that the type of the next token is the expected, and consumes the token.

Returns:

The value of the next token; an interned String iff the token represents an identifier, true, false, null, or an operator

Throws:

CompileException - The next token's type is not the expected

IOException

read

int read(TokenType... expected)
  throws CompileException,
IOException

Verifies that the type of the next token is one of the expected, and consumes the token.

Returns:

The index of the first of the expected types that is the next token's type; -1 if the type of the next token is none of the expected

Throws:

CompileException - The next token's type is none of the expected

IOException

peekRead

boolean peekRead(String suspected)
          throws CompileException,
IOException

Checks whether the value of the next token equals the suspected; if so, consumes the token.

Throws:

CompileException

IOException

peekRead

int peekRead(String... suspected)
      throws CompileException,
IOException

Checks whether the value of the next token is one of the suspected; if so, consumes the token.

Returns:

The index of the first of the suspected that equals the next token's value; -1 iff the next token's value equals none of the suspected

Throws:

CompileException

IOException

peekRead

@Nullable
String peekRead(TokenType suspected)
         throws CompileException,
IOException

Checks whether the type of the next token is the suspected; if so, consumes the token.

Returns:

The value of the next token; an interned String iff the token represents an identifier, true, false, null, or an operator

Throws:

CompileException

IOException

peekRead

int peekRead(TokenType... suspected)
      throws CompileException,
IOException

Checks whether the type of the next token is one of the suspected; if so, consumes the token.

Returns:

The index of the elements that is the next token's type, or -1 iff the type of next token is none of the suspected

Throws:

CompileException

IOException

setWarningHandler

void setWarningHandler(@Nullable
 WarningHandler warningHandler)

By default, warnings are discarded, but an application my install a WarningHandler.

Notice that there is no Parser.setErrorHandler() method, but parse errors always throw a CompileException. The reason being is that there is no reasonable way to recover from parse errors and continue parsing, so there is no need to install a custom parse error handler.

Parameters:

warningHandler - null to indicate that no warnings be issued

location

Location location()

Returns:

The location of the first character of the previously read (not peeked!) token