ds300

public abstract class BaseAST {
  public abstract void accept(Visitor v);
}

public abstract class Visitor {
	public abstract void visitBinOpNode(Expression lhs,
					                   Op op,
					                   Expression rhs);
	public abstract void visitIdentNode(String ident);
}

ds300

# let's start with this:

siteswaplist = []
while len(siteswap) > 0:
    if siteswap[0] == "a":
        siteswaplist.append(10)
        siteswap = siteswap[1:]
    if siteswap[0] == "b":
        siteswaplist.append(11)
        siteswap = siteswap[1:]

ds300

<?xml version="1.0" encoding="UTF-8" ?>
<testsuite failures="0" time="1.319" errors="1" skipped="0" tests="8" name="uk.ac.susx.mlcl.byblo.commands.ExternalCountCommandTest">
  <properties>
    <property name="java.runtime.name" value="Java(TM) SE Runtime Environment"/>
    <property name="sun.boot.library.path" value="/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Libraries"/>
    <property name="java.vm.version" value="20.8-b03-424"/>
    <property name="awt.nativeDoubleBuffering" value="true"/>
    <property name="gopherProxySet" value="false"/>
    <property name="mrj.build" value="11M3720"/>
    <property name="java.vm.vendor" value="Apple Inc."/>