summaryrefslogtreecommitdiffstats
path: root/src/node.h
blob: b62e9c0f532957d9f794ab6dbd359ceb3373d0c6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
#ifndef ABAKUS_NODE_H
#define ABAKUS_NODE_H
/*
 * node.h - part of abakus
 * Copyright (C) 2004, 2005 Michael Pyne <[email protected]>
 *
 * 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <tqstring.h>

#include "numerictypes.h"

class Node;
class Function;

template <class T> class SharedPtr;
typedef SharedPtr<Node> NodePtr;

/**
 * A class that operates on a Node.  Called recursively on a node and all
 * of its tqchildren.
 */
class NodeFunctor
{
    public:
    virtual void operator()(const Node *node) = 0;
    virtual ~NodeFunctor() { }
};

class Node
{
    public:
    virtual ~Node() { }
    virtual Abakus::number_t value() const = 0;

    // Deletes a node only if it isn't a function, since those are
    // typically read-only.
    virtual void deleteNode(Node *node);

    // Calls functor() on all subtqchildren and this.
    virtual void applyMap(NodeFunctor &fn) const = 0;

    // Returns an infix representation of the expression.
    virtual TQString infixString() const = 0;

    // Returns the derivative of the node.
    virtual Abakus::number_t derivative() const = 0;
};

class BaseFunction : public Node
{
    public:
    BaseFunction(const char *name);

    virtual TQString name() const { return m_name; }
    virtual const Function *function() const;

    private:
    TQString m_name;
    const Function *m_function;
};

class UnaryFunction : public BaseFunction
{
    public:
    UnaryFunction(const char *name, Node *operand);
    virtual ~UnaryFunction();

    virtual Node *operand() const { return m_node; }
    virtual void setOperand(Node *operand);

    virtual void applyMap(NodeFunctor &fn) const;
    virtual TQString infixString() const;

    private:
    Node *m_node;
};

// Calculates the approximate derivative of its operand.
class DerivativeFunction : public Node
{
    public:
    DerivativeFunction(Node *operand, Node *where) : 
        m_operand(operand), m_where(where) { }
    ~DerivativeFunction();

    virtual Abakus::number_t value() const;

    virtual void applyMap(NodeFunctor &fn) const;

    // Returns an infix representation of the expression.
    virtual TQString infixString() const;

    virtual Abakus::number_t derivative() const;

    private:
    Node *m_operand;
    Node *m_where;
};

class UserDefinedFunction : public UnaryFunction
{
    public:
    UserDefinedFunction(const char *name, Node *operand) : UnaryFunction(name, operand) { };

    virtual Abakus::number_t value() const { return operand()->value(); }
    virtual Abakus::number_t derivative() const { return operand()->derivative(); }
};

class BuiltinFunction : public UnaryFunction
{
    public:
    BuiltinFunction(const char *name, Node *operand);

    virtual Abakus::number_t value() const;
    virtual Abakus::number_t derivative() const;
};

class UnaryOperator : public Node
{
    public:
    typedef enum { Negation } Type;

    UnaryOperator(Type type, Node *operand);
    virtual ~UnaryOperator();

    virtual void applyMap(NodeFunctor &fn) const;
    virtual TQString infixString() const;

    virtual Abakus::number_t value() const;
    virtual Abakus::number_t derivative() const;

    virtual Type type() const { return m_type; }
    virtual Node *operand() const { return m_node; }

    private:
    Type m_type;
    Node *m_node;
};

class BinaryOperator : public Node
{
    public:
    typedef enum { Addition, Subtraction, Multiplication, Division, Exponentiation } Type;

    BinaryOperator(Type type, Node *left, Node *right);
    virtual ~BinaryOperator();

    virtual void applyMap(NodeFunctor &fn) const;
    virtual TQString infixString() const;

    virtual Abakus::number_t value() const;
    virtual Abakus::number_t derivative() const;

    virtual Type type() const       { return m_type; }
    virtual Node *leftNode() const  { return m_left; }
    virtual Node *rightNode() const { return m_right; }

    private:
    bool isSimpleNode(Node *node) const;

    Type m_type;
    Node *m_left, *m_right;
};

class Identifier : public Node
{
    public:
    Identifier(const char *name);

    virtual void applyMap(NodeFunctor &fn) const;
    virtual TQString infixString() const { return name(); }

    virtual Abakus::number_t value() const;
    virtual Abakus::number_t derivative() const
    {
        if(name() == "x")
            return "1";
        else
            return "0";
    }

    virtual TQString name() const { return m_name; }

    private:
    TQString m_name;
};

class NumericValue : public Node
{
    public:
    NumericValue(const Abakus::number_t value) : m_value(value) { }

    virtual void applyMap(NodeFunctor &fn) const { fn(this); }
    virtual TQString infixString() const;

    virtual Abakus::number_t value() const { return m_value; }
    virtual Abakus::number_t derivative() const { return "0"; }

    private:
    Abakus::number_t m_value;
};

#endif

// vim: set et sw=4 ts=8: