/*
* Copyright (c) 2005, Graph Builder
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of Graph Builder nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.graphbuilder.math;
/**
A node of an expression tree that represents a variable or a function.
*/
public abstract class
TermNode extends
Expression {
protected
String name = null;
protected boolean
negate = false;
public
TermNode(
String name, boolean
negate) {
setName(
name);
setNegate(
negate);
}
/**
Returns true if the term should negate the result before returning it in the eval method.
*/
public boolean
getNegate() {
return
negate;
}
public void
setNegate(boolean
b) {
negate =
b;
}
/**
Returns the name of the term.
*/
public
String getName() {
return
name;
}
/**
Sets the name of the term. Valid names must not begin with a digit or a decimal, and must not contain
round brackets, operators, commas or whitespace.
@throws IllegalArgumentException If the name is null or invalid.
*/
public void
setName(
String s) {
if (
s == null)
throw new
IllegalArgumentException("name cannot be null");
if (!
isValidName(
s))
throw new
IllegalArgumentException("invalid name: " +
s);
name =
s;
}
private static boolean
isValidName(
String s) {
if (
s.
length() == 0) return false;
char
c =
s.
charAt(0);
if (
c >= '0' &&
c <= '9' ||
c == '.' ||
c == ',' ||
c == '(' ||
c == ')' ||
c == '^' ||
c == '*' ||
c == '/' ||
c == '+' ||
c == '-' ||
c == ' ' ||
c == '\t' ||
c == '\n')
return false;
for (int
i = 1;
i <
s.
length();
i++) {
c =
s.
charAt(
i);
if (
c == ',' ||
c == '(' ||
c == ')' ||
c == '^' ||
c == '*' ||
c == '/' ||
c == '+' ||
c == '-' ||
c == ' ' ||
c == '\t' ||
c == '\n')
return false;
}
return true;
}
}