Snobol4 语言 栈数据结构应用 表达式求值与括号匹配

阿木博主一句话概括：Snobol4 语言栈数据结构应用：表达式求值与括号匹配

阿木博主为你简单介绍：
Snobol4 是一种古老的编程语言，以其简洁的语法和强大的字符串处理能力而闻名。本文将探讨 Snobol4 语言中栈数据结构的应用，主要围绕表达式求值和括号匹配两个主题展开。通过分析 Snobol4 的语法特性和栈数据结构的原理，我们将实现一个简单的表达式求值器和一个括号匹配器。

关键词：Snobol4，栈数据结构，表达式求值，括号匹配

一、
Snobol4 语言是一种高级编程语言，最初设计用于文本处理。它具有独特的语法和丰富的字符串操作功能。栈数据结构是一种先进后出（FILO）的数据结构，在 Snobol4 语言中有着广泛的应用。本文将探讨如何利用 Snobol4 语言中的栈数据结构来实现表达式求值和括号匹配。

二、栈数据结构原理
栈是一种线性数据结构，遵循先进后出（FILO）的原则。在 Snobol4 语言中，栈可以通过数组或列表来实现。以下是一个简单的栈数据结构的实现：

snobol
:stack
0 !stack-size
0 !stack-top
0 !stack-array

:push
!stack-top + 1 !stack-top
!stack-array !stack-top !stack-array

:pop
!stack-top - 1 !stack-top
!stack-array !stack-top !temp
!temp


在这个实现中，`!stack-array` 是一个数组，用于存储栈中的元素；`!stack-top` 是栈顶指针；`!stack-size` 是栈的最大容量。

三、表达式求值
表达式求值是编程语言中常见的一个功能。在 Snobol4 语言中，我们可以使用栈数据结构来实现一个简单的表达式求值器。以下是一个基于 Snobol4 的表达式求值器的实现：

```snobol
:expression-eval
0 !result
0 !operator
0 !operand

:read-operand
:read-operand
!char = input
!char '0' '<' = !is-digit
!char ' ' '=' '<' = !is-space
!is-digit | !is-space
!char ' ' '=' '<' = !is-space
!char '0' '<' = !is-digit
!is-digit
!char - '0' + !operand 10 !operand
!char ' ' '=' '<' = !is-space
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!is-digit
!char ' ' '=' '<' = !is-space
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' = !is-op
!is-op
!operator !char !operator
!operand !result !result
!result !operand !result
!operand !operator !operand
!operator !result !result
!result !operand !result
!result
!is-space
!char ' ' '=' '<' = !is-space
!char '+' '=' '<' = !is-op
!char '-' '=' '<' = !is-op
!char '' '=' '<' = !is-op
!char '/' '=' '<' =