eval_expr_to_rpn.php

泛微协同办公系统标准版E-office V5.5的源代码内含泛微办公系统V5.5自动注册文件。

<?php

function get_token_array( $string )
{
	$token = array( );
	$pos = array( );
	$str_len = 0;
	while ( true )
	{
		if ( 1 === preg_match( "/^([%,\\^\\+\\-\\*\\/\\(\\)]).*\$/", $string, $sub ) )
		{
			array_push( $token, $sub[1] );
			array_push( $pos, $str_len );
			$string = substr( $string, strlen( $sub[1] ) );
			$str_len += strlen( $sub[1] );
		}
		else if ( 1 === preg_match( "/^(([0-9]+[\\.]?[0-9]*)|([0-9]*[\\.]?[0-9]+)).*\$/", $string, $sub ) )
		{
			array_push( $token, floatval( $sub[1] ) );
			array_push( $pos, $str_len );
			$string = substr( $string, strlen( $sub[1] ) );
			$str_len += strlen( $sub[1] );
		}
		else
		{
			if ( 1 === preg_match( "/^([a-zA-Z_][0-9a-zA-Z_]*\\().*\$/", $string, $sub ) )
			{
				array_push( $token, $sub[1] );
				array_push( $pos, $str_len );
				$string = substr( $string, strlen( $sub[1] ) );
				$str_len += strlen( $sub[1] );
			}
			else
			{
				if ( !( 1 === preg_match( "/^(\\s+).*\$/", $string, $sub ) ) )
				{
					break;
				}
				$string = substr( $string, strlen( $sub[1] ) );
				$str_len += strlen( $sub[1] );
				continue;
				break;
			}
		}
	}
	array_push( $pos, $str_len );
	if ( $string != "" )
	{
		return $str_len;
	}
	return array(
		$token,
		$pos
	);
}

function current_token( )
{
	global $g_count;
	global $g_token;
	return $g_token[$g_count];
}

function next_token( )
{
	global $g_count;
	global $g_token;
	if ( isset( $g_token[$g_count + 1] ) )
	{
		++$g_count;
		return $g_token[$g_count];
	}
	else
	{
		return false;
	}
}

function error_pos( )
{
	global $g_count;
	global $g_pos;
	return $g_pos[$g_count];
}

function eval_expr_to_rpn( $string )
{
	global $g_count;
	global $g_token;
	global $g_pos;
	global $g_error;
	$g_error = null;
	$g_count = 0;
	$info = get_token_array( $string );
	if ( !is_array( $info ) )
	{
		error( 25, $info );
	}
	else
	{
		$g_token = $info[0];
		$g_pos = $info[1];
		array_push( $g_token, "End" );
		$ans = fun_a( );
		if ( $g_count != sizeof( $g_token ) - 1 )
		{
			error( 24, error_pos( ) );
		}
		return $ans;
	}
}

function fun_a( )
{
	$ans_1 = fun_b( );
	$ans_2 = fun_a_( );
	if ( $ans_1 === false || $ans_2 === false )
	{
		error( 1, error_pos( ) );
		return false;
	}
	if ( $ans_2 === "" )
	{
		return $ans_1;
	}
	else
	{
		return $ans_1." ".$ans_2;
	}
}

function fun_a_( )
{
	if ( "+" === current_token( ) || "-" === current_token( ) )
	{
		$op = current_token( );
		if ( $op === "+" )
		{
			$op = "ADD";
		}
		else if ( $op === "-" )
		{
			$op = "SUB";
		}
		if ( false === next_token( ) )
		{
			error( 2, error_pos( ) );
			return false;
		}
		else
		{
			$ans_1 = fun_b( );
			$ans_2 = fun_a_( );
			if ( $ans_1 === false || $ans_2 === false )
			{
				error( 3, error_pos( ) );
				return false;
			}
			if ( $ans_2 === "" )
			{
				return $ans_1." ".$op;
			}
			else
			{
				return $ans_1." ".$op." ".$ans_2;
			}
		}
	}
	else
	{
		return "";
	}
}

function fun_b( )
{
	$ans_1 = fun_c( );
	$ans_2 = fun_b_( );
	if ( $ans_1 === false || $ans_2 === false )
	{
		error( 4, error_pos( ) );
		return false;
	}
	if ( $ans_2 === "" )
	{
		return $ans_1;
	}
	else
	{
		return $ans_1." ".$ans_2;
	}
}

function fun_b_( )
{
	if ( "*" === current_token( ) || "/" === current_token( ) || "%" === current_token( ) )
	{
		$op = current_token( );
		if ( $op === "*" )
		{
			$op = "MUL";
		}
		else if ( $op === "/" )
		{
			$op = "DIV";
		}
		else if ( $op === "%" )
		{
			$op = "MOD";
		}
		if ( false === next_token( ) )
		{
			error( 5, error_pos( ) );
			return false;
		}
		else
		{
			$ans_1 = fun_c( );
			$ans_2 = fun_b_( );
			if ( $ans_1 === false || $ans_2 === false )
			{
				error( 6, error_pos( ) );
				return false;
			}
			if ( $ans_2 === "" )
			{
				return $ans_1." ".$op;
			}
			else
			{
				return $ans_1." ".$op." ".$ans_2;
			}
		}
	}
	else if ( 1 === preg_match( "/^[\\+\\-]?(([0-9]+[\\.]?[0-9]*)|([0-9]*[\\.]?[0-9]+))([eE][+-]?[0-9]+)?\$/", current_token( ) ) || "(" === current_token( ) || 1 === preg_match( "/^([a-zA-Z_][0-9a-zA-Z_]*\\()\$/", current_token( ) ) )
	{
		$ans_1 = fun_c( );
		$ans_2 = fun_b_( );
		if ( $ans_1 === false || $ans_2 === false )
		{
			error( 30, error_pos( ) );
			return false;
		}
		if ( $ans_2 === "" )
		{
			return $ans_1." "."MUL";
		}
		else
		{
			return $ans_1." "."MUL"." ".$ans_2;
		}
	}
	else
	{
		return "";
	}
}

function fun_c( )
{
	if ( "-" === current_token( ) || "+" === current_token( ) )
	{
		if ( "-" === current_token( ) )
		{
			$op = " NEC";
		}
		if ( "+" === current_token( ) )
		{
			$op = "";
		}
		if ( false === next_token( ) )
		{
			error( 7, error_pos( ) );
			return false;
		}
		$ans = fun_c( );
		if ( $ans === false )
		{
			error( 8, error_pos( ) );
			return false;
		}
		else
		{
			return $ans.$op;
		}
	}
	else
	{
		$ans = fun_d( );
		if ( $ans === false )
		{
			error( 9, error_pos( ) );
			return false;
		}
		else
		{
			return $ans;
		}
	}
}

function fun_d( )
{
	$ans_1 = fun_x( );
	if ( $ans_1 === false )
	{
		error( 10, error_pos( ) );
		return false;
	}
	if ( "^" === current_token( ) )
	{
		if ( false === next_token( ) )
		{
			error( 11, error_pos( ) );
			return false;
		}
		if ( "-" === current_token( ) || "+" === current_token( ) )
		{
			$ans_2 = fun_c( );
			if ( $ans_2 === false )
			{
				error( 12, error_pos( ) );
				return false;
			}
			return $ans_1." ".$ans_2." "."POW";
		}
		else
		{
			$ans_2 = fun_d( );
			if ( $ans_2 === false )
			{
				error( 13, error_pos( ) );
				return false;
			}
			return $ans_1." ".$ans_2." "."POW";
		}
	}
	else
	{
		return $ans_1;
	}
}

function fun_f( )
{
	$ans_1 = fun_a( );
	if ( $ans_1 === false )
	{
		error( 14, error_pos( ) );
		return false;
	}
	if ( "," === current_token( ) )
	{
		if ( false === next_token( ) )
		{
			error( 15, error_pos( ) );
			return false;
		}
		$ans_2 = fun_f( );
		if ( $ans_2 === false )
		{
			error( 16, error_pos( ) );
			return false;
		}
		return $ans_1." ".$ans_2;
	}
	else
	{
		return $ans_1;
	}
}

function fun_x( )
{
	if ( "(" === current_token( ) )
	{
		if ( false === next_token( ) )
		{
			error( 17, error_pos( ) );
			return false;
		}
		$ans = fun_a( );
		if ( $ans === false )
		{
			error( 18, error_pos( ) );
			return false;
		}
		if ( ")" != current_token( ) )
		{
			error( 19, error_pos( ) );
			return false;
		}
		next_token( );
		return $ans;
	}
	else if ( 1 === preg_match( "/^[\\+\\-]?(([0-9]+[\\.]?[0-9]*)|([0-9]*[\\.]?[0-9]+))([eE][+-]?[0-9]+)?\$/", current_token( ) ) )
	{
		$ans = current_token( );
		next_token( );
		return $ans;
	}
	else if ( 1 === preg_match( "/^([a-zA-Z_][0-9a-zA-Z_]*\\()\$/", current_token( ) ) )
	{
		$fun_name = substr( current_token( ), 0, -1 );
		if ( false === next_token( ) )
		{
			error( 20, error_pos( ) );
			return false;
		}
		if ( ")" === current_token( ) )
		{
			if ( false === next_token( ) )
			{
				error( 26, error_pos( ) );
				return false;
			}
			return "()".$fun_name;
		}
		else
		{
			$ans = fun_f( );
			if ( $ans === false )
			{
				error( 21, error_pos( ) );
				return false;
			}
			if ( ")" != current_token( ) )
			{
				error( 22, error_pos( ) );
				return false;
			}
			next_token( );
			return "( ".$ans." )".$fun_name;
		}
	}
	else
	{
		error( 23, error_pos( ) );
		return false;
	}
}

function error( $info, $pos )
{
	global $g_error;
	if ( $g_error === null )
	{
		$g_error = array(
			$info,
			$pos
		);
	}
}

function get_error_info( )
{
	global $g_error;
	$info_array = array( 19 => "缺少右括号", 22 => "缺少右括号", 23 => "语法错误", 24 => "语法错误", 25 => "输入错误" );
	if ( array_key_exists( $g_error[0], $info_array ) )
	{
		return $info_array[$g_error[0]];
	}
	else if ( $g_error === null )
	{
		return null;
	}
	else
	{
		return "错误：#{$g_error[0]}";
	}
}

function get_error_pos( )
{
	global $g_error;
	if ( $g_error === null )
	{
		return null;
	}
	else
	{
		return $g_error[1];
	}
}

?>