/**************************************************
*?file:?calc.cpp
*?date:?2006-06-30
*?author:?ideawu
*?describe:?a?really?small?and?simple?caculator.
*			with?known?bugs.
**************************************************/

#include?
#include?
#include?

#include?“Parser.h“

float?calc（SyntaxTree?*tree）;

int?main（int?argc?char*?argv[]）{
	char?buf[1024]?=?“a=“;
	SyntaxTree?*tree?=?NULL;
	Lexer?*lexer?=?new?Lexer（）;
	Parser?*parser?=?new?Parser（）;
	
	lexer->setSrc（buf?1024）;
	parser->setLexer（lexer）;
	
	printf（“>>“）;
	scanf（“%s“?&buf[2]）;
	while（strcmp（buf?“a=quit“）?!=?0）{
		tree?=?parser->parse（）;

		if（tree!=NULL）{
			//tree->display（）;
			printf（“%g\n“?calc（tree->getRight（）））;
		}else{
			parser->printError（）;
		}
		printf（“>>“）;
		scanf（“%s“?&buf[2]）;
		parser->reset（）;
	}

	printf（“\n“）;
	
	return?0;
}

float?calc（SyntaxTree?*tree）{
	float?a=0?b=0?val=0;
	
	if（tree?!=?NULL）{
		if（tree->getRootNode（）->getType（）?==?NUM）{
			return?tree->getRootNode（）->getValue（）;
		}
		a?=?calc（tree->getLeft（））;
		b?=?calc（tree->getRight（））;
	
		switch（tree->getRootNode（）->getType（））{
			case?PLUS:
				val?=?a?+?b;
				break;
			case?MINUS:
				val?=?a?-?b;
				break;
			case?MUL:
				val?=?a?*?b;
				break;
			case?DIV:
				if（b?!=?0）{
					val?=?a?/?b;
				}
				break;
			default:
				break;
		}
	}

	return?val;
	
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1368??2006-06-30?10:27??簡易編譯器??源代碼\calc.cpp

?????文件????????807??2006-04-15?19:34??簡易編譯器??源代碼\common.h

?????文件???????5186??2006-06-30?08:10??簡易編譯器??源代碼\Lexer.cpp

?????文件????????515??2006-06-30?07:56??簡易編譯器??源代碼\Lexer.h

?????文件????????716??2006-04-20?14:59??簡易編譯器??源代碼\main.cpp

?????文件????????668??2008-06-02?16:29??簡易編譯器??源代碼\Makefile

?????文件???????7728??2006-06-30?08:48??簡易編譯器??源代碼\Parser.cpp

?????文件????????810??2006-06-30?07:31??簡易編譯器??源代碼\Parser.h

?????文件???????3899??2006-06-30?08:28??簡易編譯器??源代碼\SyntaxTree.cpp

?????文件???????1201??2006-04-15?07:56??簡易編譯器??源代碼\SyntaxTree.h

?????文件???????1570??2006-06-30?08:28??簡易編譯器??源代碼\SyntaxTreeNode.cpp

?????文件???????1106??2006-04-15?07:50??簡易編譯器??源代碼\SyntaxTreeNode.h

?????文件??????65730??2006-06-26?09:31??簡易編譯器??源代碼\temp.txt

?????文件?????????40??2006-06-26?09:21??簡易編譯器??源代碼\test.txt

?????文件????????769??2006-04-17?17:03??簡易編譯器??源代碼\test_complex.txt

?????文件????????113??2006-04-17?18:35??簡易編譯器??源代碼\test_error.txt

?????目錄??????????0??2011-06-16?22:11??簡易編譯器??源代碼

-----------?---------??----------?-----??----

????????????????92226????????????????????17