JSchemeMin
JSchemeMin is a implementation of the Scheme language on the Java platform.
As a implementation of the language described in the Revised7 Report on the Algorithmic Language Scheme (R7RS), JSchemeMin supports all standard features of Scheme, including first-class procedures, proper tail calls, continuations, user-defined records, libraries, exceptions, and hygienic macro expansion.
As a JVM based implementation, JSchemeMin enables Scheme programs to use the full power of Java's API. JSchemeMin also enables Java programs to evaluate Scheme's code, so Scheme can be used as an extensions language by Java's programs.
Currently, JSchemeMin only provides a interpreter, not compiler. A basic mechanism for profiling is provided. Debugger and coverage tool is included as well.
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
Getting JSchemeMin
Clone and build from source
You can surely clone this repository and build it using ant:
git clone https://github.com/chungkwong/JSchemeMin.git
cd jschememin
ant
Maven central repository
If you are using Maven, you can add the following into your pom.xml:
<dependency>
<groupId>com.github.chungkwong</groupId>
<artifactId>jschememin</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>If you are using something like ivy or gradle, you can also try the central repository.
Download JAR from Github
See https://github.com/chungkwong/JSchemeMin/releases ,although that may not be up-to-date.
Usage
Standlone
You can start the command line interpreter by something like
java -jar JSchemeMin.jar
A -d option will lead to the debugger.
API
The API of JSchemeMin is contained in the package com.github.chungkwong.jschememin.
Since JSchemeMin have implemented the javax.script API of the Java platform, you should be familar to the usage. For example, a naive Scheme interpreter may look like:
public static void main(String[] args) throws ScriptException{
Scanner in=new Scanner(System.in);
Evaluator evaluator=(Evaluator)EvaluatorFactory.INSTANCE.getScriptEngine();
while(in.hasNextLine()){
System.out.println(evaluator.eval(in.nextLine()));
}
}If you want to use Scheme on computer-generated data, you can bypass the step parse by providing internal representation of the data.
JSchemeMin
JSchemeMin 是又一个JVM平台上的Scheme语言实现。
作为Revised7 Report on the Algorithmic Language Scheme (R7RS)的实现，JSchemeMin支持Scheme的所有标准特性，包括头等公民地位的过程、尾递归优化、继续、用户定义记录、库（包括R7RS附录A中全部语法和过程，不只base）、异常和健康宏展开。
作为基于JVM的实现，JSchemeMin 让Scheme程序可以调用Java平台的API，也让Java程序运行Scheme代码，这使Scheme可作为Java（以至别的JVM语言）程序的一种扩展语言，类似Nashorn之于JavaScript。
目前，JSchemeMin 只提供解释器而非编译器。基本的性能监视机制已经存在。调试器和覆盖率工具也已经提供。
性能并非JSchemeMin的主要设计目标，大部分情况下用明显的实现方式，不为性能牺牲实现的简单性，但相信足以满足预期的需要。
本软件为自由软件: 你可以在自由软件基金会的GNU通用公共许可，版本3或按你的意愿更新的版本，的条款下再分发它和/或修改它。
获取JSchemeMin
克隆Github仓库并从源码构建
git clone https://github.com/chungkwong/JSchemeMin.git
cd jschememin
ant
Maven中央仓库
若你在用Maven，把以下依赖加到你的 pom.xml:
<dependency>
<groupId>com.github.chungkwong</groupId>
<artifactId>jschememin</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>若你在用ivy或gradle也可以类似地从中央仓库获取JAR。
下载GitHub上发布的JAR
见 https://github.com/chungkwong/JSchemeMin/releases，虽然可能过时。
用法
作为程序
运行类似于java -jar JSchemeMin.jar的命令，-d选项会启用调试器。
作为库
API位于包 com.github.chungkwong.jschememin。
你可以使用基于javax.script的API，如以下是一个简陋的Scheme解释器：
public static void main(String[] args) throws ScriptException{
Scanner in=new Scanner(System.in);
Evaluator evaluator=(Evaluator)EvaluatorFactory.INSTANCE.getScriptEngine();
while(in.hasNextLine()){
System.out.println(evaluator.eval(in.nextLine()));
}
}对于机器生成的脚本，可以用低级API来避开解析文本的开销。