Consumes the current symbol in the stream. This method has the following
effects:
<ul>
<li><strong>Forward movement:</strong> The value of {@link #index index()}
before calling this method is less than the value of {@code index()}
after calling this method.</li>
<li><strong>Ordered lookahead:</strong> The value of {@code LA(1)} before
calling this method becomes the value of {@code LA(-1)} after calling
this method.</li>
</ul>
Note that calling this method does not guarantee that {@code index()} is
incremented by exactly 1, as that would preclude the ability to implement
filtering streams (e.g. {@link CommonTokenStream} which distinguishes
between "on-channel" and "off-channel" tokens).
@throws IllegalStateException if an attempt is made to consume the the
end of the stream (i.e. if {@code LA(1)==}{@link #EOF EOF} before calling
{@code consume}).
Consumes the current symbol in the stream. This method has the following effects:
<ul> <li><strong>Forward movement:</strong> The value of {@link #index index()} before calling this method is less than the value of {@code index()} after calling this method.</li> <li><strong>Ordered lookahead:</strong> The value of {@code LA(1)} before calling this method becomes the value of {@code LA(-1)} after calling this method.</li> </ul>
Note that calling this method does not guarantee that {@code index()} is incremented by exactly 1, as that would preclude the ability to implement filtering streams (e.g. {@link CommonTokenStream} which distinguishes between "on-channel" and "off-channel" tokens).
@throws IllegalStateException if an attempt is made to consume the the end of the stream (i.e. if {@code LA(1)==}{@link #EOF EOF} before calling {@code consume}).