private int runInternal(
CompilingEnvironment environment,
ByteCodeWriter writer,
List<Value> statement,
ICompiler compiler,
int position)
throws ByteScriptSyntaxException {
int start = position;
boolean needsScopePush = false;
LinkedList<Value> params = new LinkedList<Value>();
if (statement.get(position).getValueAsString().equals("{")) {
position += CompileUtil.getMatchingParas(position, statement, params, "{", "}");
needsScopePush = true;
} else {
position += CompileUtil.getUntilMatch(position, statement, params, ";");
}
if (needsScopePush) {
writer.writePushStack(false);
}
try {
compiler.compile(params, writer, environment, 0);
} catch (Exception ex) {
throw new ByteScriptSyntaxException("unable to compile sub scope of else statement", ex);
}
if (needsScopePush) {
writer.writePopStack(false);
}
return position - start;
}
@Override
public int compile(
CompilingEnvironment environment,
ByteCodeWriter writer,
List<Value> statement,
ICompiler compiler,
int position)
throws ByteScriptSyntaxException {
int start = position;
/** first check that there is actually an if */
if (!statement.get(position).getValueAsString().equals("if")) {
throw new ByteScriptSyntaxException("invalid beginning construct for an if statement");
}
/** this will let us know if multiple else statements in a row occur */
boolean onElse = false;
boolean onFirst = true;
while (true) {
if (statement.get(position++).getValueAsString().equals("if")) {
if (onElse) {
/**
* this means there is an if statement right after this statement, so we are done with
* these
*/
break;
}
LinkedList<Value> params = new LinkedList<Value>();
position += CompileUtil.getMatchingParas(position, statement, params, "(", ")");
try {
writer.writeStatement(params, environment);
} catch (Exception ex) {
throw new ByteScriptSyntaxException("unable to write logic in if statement", ex);
}
if (!onFirst) {
writer.resolveTag("go_to_next_else");
}
onFirst = false;
writer.writeOperation(ByteCodeOperation.BRACH);
Value if_result = environment.pop();
if (if_result.type != ValueType.BOOLEAN) {
throw new ByteScriptSyntaxException("if statement does not result to a boolean");
}
writer.setTag_Temp("if_statement_is_false");
position += runInternal(environment, writer, statement, compiler, position) - 1;
writer.setTag_Temp("finished_else_if");
writer.resolveTag("if_statement_is_false");
} else if (statement.get(position).getValueAsString().equals("else")) {
if (onFirst) {
/** i dont think this will ever happen, but its more of a sanity check. */
throw new ByteScriptSyntaxException("you cannot start an if statement with an if");
}
position++;
if (statement.get(position).getValueAsString().equals("if")) {
writer.setTag_Temp("go_to_next_else");
continue;
}
if (onElse) {
throw new ByteScriptSyntaxException("you cannot have multiple else statements");
}
onElse = true;
position += runInternal(environment, writer, statement, compiler, position);
writer.setTag_Temp("finished_else_if");
break;
} else {
break;
}
}
writer.resolveTag("finished_else_if");
return position - start;
}