Scheme 语言 文件流管理 with input from file 自动关闭流的技巧

Schemeamuwap 发布于 5 天前 7 次阅读

阿木博主一句话概括：深入解析Scheme语言【1】文件流管理【2】：with-input-from-file【3】自动关闭流【4】的技巧

阿木博主为你简单介绍：
Scheme语言作为一种函数式编程【5】语言，以其简洁、优雅和高效的特点受到许多程序员的喜爱。在文件流管理方面，Scheme提供了丰富的库函数【6】，其中`with-input-from-file`是一个常用的函数，用于读取文件内容。本文将深入探讨`with-input-from-file`的使用技巧，特别是如何确保文件流在使用后被自动关闭。

关键词：Scheme语言，文件流管理，with-input-from-file，自动关闭流

一、
在编程中，正确管理文件流是非常重要的，它不仅关系到程序的稳定性，还可能影响性能。在Scheme语言中，`with-input-from-file`是一个用于读取文件内容的函数，它能够自动处理文件的打开和关闭，简化了文件流的管理。本文将围绕`with-input-from-file`的使用，探讨如何确保文件流在使用后被自动关闭。

二、with-input-from-file函数简介
`with-input-from-file`是Scheme语言标准库中的一个函数，其原型如下：

```scheme
(with-input-from-file path !key (port input) (eof-error? f) (error? f) (element-type 'char) (encoding f) (external-format 'utf-8) (buffer-size f) (buffer f) (line-column? f) (unbuffered? f) (element? f) (eof-value f) (eof-action 'error) (error-element-type 'char) (error-encoding 'utf-8) (error-external-format 'utf-8) (error-buffer-size f) (error-buffer f) (error-line-column? f) (error-unbuffered? f) (error-element? f) (error-eof-value f) (error-eof-action 'error) (error-error? f) (error-port input) (error-error-element-type 'char) (error-error-encoding 'utf-8) (error-error-external-format 'utf-8) (error-error-buffer-size f) (error-error-buffer f) (error-error-line-column? f) (error-error-unbuffered? f) (error-error-element? f) (error-error-eof-value f) (error-error-eof-action 'error) (error-error-error? f) (error-error-error-port input) (error-error-error-element-type 'char) (error-error-error-encoding 'utf-8) (error-error-error-external-format 'utf-8) (error-error-error-buffer-size f) (error-error-error-buffer f) (error-error-error-line-column? f) (error-error-error-unbuffered? f) (error-error-error-element? f) (error-error-error-eof-value f) (error-error-error-eof-action 'error) (error-error-error-error? f) (error-error-error-error-port input) (error-error-error-error-element-type 'char) (error-error-error-error-encoding 'utf-8) (error-error-error-error-external-format 'utf-8) (error-error-error-error-buffer-size f) (error-error-error-error-buffer f) (error-error-error-error-line-column? f) (error-error-error-error-unbuffered? f) (error-error-error-error-element? f) (error-error-error-error-eof-value f) (error-error-error-error-eof-action 'error) (error-error-error-error-error? f) (error-error-error-error-error-port input) (error-error-error-error-error-element-type 'char) (error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-buffer-size f) (error-error-error-error-error-buffer f) (error-error-error-error-error-line-column? f) (error-error-error-error-error-unbuffered? f) (error-error-error-error-error-element? f) (error-error-error-error-error-eof-value f) (error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error? f) (error-error-error-error-error-error-port input) (error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-element? f) (error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-line-column? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-unbuffered? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-value f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-eof-action 'error) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-error? f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-port input) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-element-type 'char) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-encoding 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-external-format 'utf-8) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer-size f) (error-error-error-error-error-error-error-error-error-error-error-error-error-error-error-buffer f) (error-error-error-error-error-error-error-error-error-error