9주차 Discussion

[chloe-codes1]

📢 책을 읽으면서 궁금한 점들을 자유롭게 적고 대답해 주세요

9주차 진행 방식

1. 진도: 3.3 ~ 3.4.1 읽어오고 정리 & 의견 나누기
2. 문제 풀이: 3.12, 3.21, 3.24, 3.28, 3.38 문제 풀고, Github 에 올리기 (총 5문제)

[bigsaigon333]

3.12

["b", null]

["b", ["c", ["d", null]]]

[bigsaigon333]

3.21

function print_queue(queue) {
  display(front_ptr(queue));
}

[bigsaigon333]

3.24

function assoc(key, records, same_key) {
  return is_null(records)
    ? undefined
    : same_key(key, head(head(records)))
      ? head(records)
      : assoc(key, tail(records));
}

function make_table(same_key) {
  const local_table = list("*table*");
  function lookup(key_1, key_2) {
    const subtable = assoc(key_1, tail(local_table), same_key);
    if (is_undefined(subtable)) {
      return undefined;
    } else {
      const record = assoc(key_2, tail(subtable));
      return is_undefined(record) ? undefined : tail(record);
    }
  }
  function insert(key_1, key_2, value) {
    const subtable = assoc(key_1, tail(local_table));
    if (is_undefined(subtable)) {
      set_tail(
        local_table,
        pair(list(key_1, pair(key_2, value)), tail(local_table)),
      );
    } else {
      const record = assoc(key_2, tail(subtable), same_key);
      if (is_undefined(record)) {
        set_tail(subtable, pair(pair(key_2, value), tail(subtable)));
      } else {
        set_tail(record, value);
      }
    }
  }
  function dispatch(m) {
    return m === "lookup"
      ? lookup
      : m === "insert"
        ? insert
        : error(m, "unknown operation -- table");
  }
  return dispatch;
}

[bigsaigon333]

3.28

function or_gate(a1, a2, output) {
  function or_action_function() {
    const new_value = logical_or(get_signal(a1), getA_signal(a2));
    after_delay(or_gate_delay, () => set_signal(output, new_value));
  }
  add_action(a1, or_action_function);
  add_action(a2, or_action_function);
  return "ok";
}