The PowerPC 604 RISC Microprocessor - eisber.net

Printed by andi from a0.complang.tuwien.ac.atMar 29 1996 16:42 KarelTheRobotejava Page 15void put_object_at_poslint pos. Node node)if (pos 2)instruction . node;void print lint level) (if (count .= 01KarelTheRobot.println(level, *ITERATE TIMES');elseKarelTheRobot.println(level, 'ITERATE ' count • ' TIMES");KarelTheRobot.print_instr(level, instruction);int exec_step() (it (KarelTheRobot.offset 0)if ((count 0) 11 (instruction null))return incomplete_program_error;top++;if (top >- stack.length)return stack_overflow_error;stack(topl ■ count;KarelTheRobot.instruction • instruction;else (►if 1--stack(topl > 0)KarelTheRobot.offset 0;1KarelTheRobot.inatruction ■) elsetop--;KarelTheRobot.offset ■ offset;KarelTheRobot.instruction ■ next;return 0;instruction;class IfThenElseNode extends Node implements Globale (static final int description() .(if_then_else_node, is_test, is_stmt, is_stmt, is_undef);int test;Node then_stmt;Node else_stmt;IfThenElseNodel)test . undef_test;then_stmt - null;else_stmt . null;int length()return 3;int description(int pos) (return description(pos);int get_int_at_pos(int pos)(if (pos 1)return test;return 0;void put_object_at_pos(int pos, int val)if (pos 1)Mar 29 1996 16:42 KarelTheRobotjava Page 16test . val;Node get_node_at_pos(int pos)(if (pos 2)return then_stmt;else if (pos 3)return elee_stmt;return null;void put_object_at_pos(int pos. Node node) (if (pos 2)then_stmt ■ node;else if (poselse_stmt3)node;void print(int level)KarelTheRobot.println(level, 'IF + test_names(test));KarelTheRobot.println(level, 'THEW):KarelTheRobot.print_instr(level, then_stmt);KarelTheRobot.println(level, 'ELSE');KarelTheRobot.print_instr(level, else_stmt);int exec_step()if (test 0)return incomplete_program_error;if (KarelTheRobot.offset 0)if (KarelsWorld.test(teet))if (then_stmt null)return incomplete_program_error;KarelTheRobot.inntruction • then_stmt;) elseif (else_stmt null)return incomplete_program_error;KarelTheRobot.instruction ■ else_stmt;1) elseif (KarelTheRobot.offset .. 4)BackBuffer.push(true);elseDackBuffer.push(false);KarelTheRobot.offset . offset;KarelTheRobot.inetruction • next;return 0;final class CallNode extends Node implements Globalestatic final int description() ■(call_node, is_name, is_undef, is_undef, is_undef);Name definition;CallNode()definition . null;int description(int pos)return description(pos);Name get_name_at_pos(int pos)(if (pos .. 1)KarelTheRobot.java 8