2009 March 27th Friday (三月　二十七日　金曜日)

最新推荐文章于 2026-01-08 21:46:27 发布

原创最新推荐文章于 2026-01-08 21:46:27 发布 · 631 阅读

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文章标签：

#list #exception #lambda #manager #less #build

今日主要任务是对旧项目EV的源码进行研究，并计划基于这些资料开发一套新的公共线路管理系统。新系统将减少对建筑群管理的人力需求，在经济危机背景下有助于裁员，特别是减少对建筑管理员的需求。但在研究过程中发现了一些逻辑上的难点。

   Today my main task is to study some source on the old project EV. From those sources, we have to build a new management program on public
line. The new program will need less men to manage or monitor a group of building. Under the circumstance of economic crisis, it will be
a good tool in order to cut down staff, especially, building manager or monitor.

However, I found that some strange logic is here and there. It is not easy to comprehend them.

#`(1)

(define-syntax n
(lambda (x)
    (syntax-case x ()
      ((_ #(p1 p2 pe ... p4 p5))
       (syntax (list
                (list p1 p2)
                (list pe ...)
                (list p4 p5)))))))

> (n #(1 2 3 4 5 6 7 8))
((1 2) (3 4 5 6) (7 8))

(define-syntax m
(lambda (x)
    (syntax-case x ()
      ((_ p1 p2 pe ... p4 p5 . pt)
       (syntax (list
                (list p1 p2)
                (list pe ...)
                (list p4 p5)
                (list pt)))))))

> (m 1 2 3 4 5 6 7 . 8)
((1 2) (3 4 5) (6 7) (8))

(define-syntax v
(lambda (x)
    (syntax-case x ()
      ((_ p1 p2 . pt)
       (syntax (list
                (list p1 p2)
                (list pt)))))))

> (v 1 2 . 3)
((1 2) (3))

Every predicate has a alike following control flow.

        +-----------+
call -->|           |--> exit
        | predicate |
fail <--|           |<-- redo
        +-----------+
               |
exception <----+

repeat:

        +-----------+
call -->|        +->|--> exit
        | repeat | |
fail <--|        +--|<-- redo
        +-----------+
               |
exception <----+

fail:

        +-----------+
call -->|--+         |--> exit
        | | fail    |
fail <--|<-+         |<-- redo
        +-----------+
               |
exception <----+