Snobol4 语言 实战 开发文本格式化脚本实战

Snobol4^【1】 语言实战：开发文本格式化脚本

Snobol4 是一种古老的编程语言，最初由 Calvin Mooers 在1962年设计，主要用于文本处理^【2】。尽管它已经不像其他现代编程语言那样流行，但Snobol4在文本处理领域仍然有其独特的优势。本文将围绕Snobol4语言，通过一个实战案例——开发文本格式化脚本，来探讨Snobol4在文本处理中的应用。

Snobol4 简介

Snobol4 是 Snobol（StriNg Oriented and symBOlic Language）语言的第四个版本。它是一种高级编程语言，特别适合于文本处理任务。Snobol4 的语法简洁，易于理解，同时提供了丰富的文本处理功能。

Snobol4 的特点

1. 字符串处理能力：Snobol4 提供了强大的字符串处理功能，包括模式匹配^【3】、替换^【4】、分割^【5】等。
2. 符号处理^【6】：Snobol4 支持符号处理，可以方便地处理文本中的特殊字符。
3. 流控制^【7】：Snobol4 提供了丰富的流控制结构，如循环、条件语句等。
4. 数据结构^【8】：Snobol4 支持数组、列表等数据结构，便于处理复杂数据。

实战案例：文本格式化脚本

需求分析

假设我们需要开发一个文本格式化脚本，该脚本能够：

1. 将文本中的段落首行缩进^【9】两个空格。
2. 将文本中的连续空格^【10】替换为一个空格。
3. 将文本中的换行符^【11】替换为两个空格。

脚本设计

以下是一个简单的Snobol4脚本，用于实现上述文本格式化功能。

```snobol
:fmt
input
| ^ (
2 spaces
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output
)
| (
output