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Smalltalk Python Perl and Ruby SmalltalkRubyPerlPythonWeb

程序员文章站 2022-07-15 11:31:20
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http://en.wikipedia.org/wiki/Yukihiro_Matsumoto

Smalltalk

Like Smalltalk Ruby is a dynamic and pure object-oriented language. Both languages are dynamic because they do not use static type information. They are pure because all values are objects and are classified into classes that are objects themselves. Both are also designed to be object-oriented languages from the beginning, and they both support garbage collection.

As the design of the World Wide Web was not inherently dynamic, early hypertext consisted of hand-coded HTML that was published on web servers. Any modifications to published pages needed to be performed by the pages' author. To provide a dynamic web page that reflected user inputs, the Common Gateway Interface (CGI) standard was introduced for interfacing external applications with web servers.[1] CGI could adversely affect server load, though, since each request had to start a separate process. In Smalltalk, control flow structures such as conditionals are done by sending messages to the objects—at least, that's how it appears. Sometimes this makes Smalltalk programs unnatural and hard to read. In Ruby, control flow structure is far more conservative. Smalltalk is an operating system and a programming environment. The program is basically an image within the environment that is constructed through interaction via browsers. Unlike Smalltalk programs, Ruby programs are clearly separated from the language and its interpreter. Programmers wanted tighter integration with the web server to enable high traffic web applications. The Apache HTTP Server, for example, supports modules that can extend the web server with arbitrary code executions (such as mod perl) or forward specific requests to a web server that can handle dynamic content (such as mod jk). Some web servers (such as Apache Tomcat) were specifically designed to handle dynamic content by executing code written in some languages, such as Java. Around the same time, new languages were being developed specifically for use in the web, such as ColdFusion, PHP and Active Server Pages. While the vast majority of languages available to programmers to use in creating dynamic web pages have libraries to help with common tasks, web applications often require specific libraries that are useful in web applications, such as creating HTML (for example, JavaServer Faces). Eventually, mature, "full stack" frameworks appeared, that often gathered multiple libraries useful for web development into a single cohesive software stack for web developers to use. Examples of this include JavaEE (Servlets), WebObjects, OpenACS, and Ruby on Rails. 

 

Perl

Ruby and two other great "P" languages (Perl and Python) often are classified as scripting languages. They are scripting languages, but probably not in the sense that you imagine. They are scripting languages for these reasons: * They support a fast development cycle (edit-run-edit) by interpreters. No compilation is needed. * They focus on quick programming by requiring you to code less. For example, you don't have to deal with static types of variables. Fewer declarations are needed in programs. Because of these attributes, these languages can be used for everyday task one-liners. Imagine developing a so-called one-liner (such as scanning the log files) in C, for example. * A strong set of built-in libraries supports the handling of text and files.