- Renamed flag NO_GINAC_NAMESPACE to NO_NAMESPACE_GINAC because of m4.
[ginac.git] / ginac / expair.h
1 /** @file expair.h
2  *
3  *  Definition of expression pairs (building blocks of expairseq). */
4
5 /*
6  *  GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or
11  *  (at your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to the Free Software
20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22
23 #ifndef __GINAC_EXPAIR_H__
24 #define __GINAC_EXPAIR_H__
25
26 #include "ex.h"
27 #include "numeric.h"
28
29 #ifndef NO_NAMESPACE_GINAC
30 namespace GiNaC {
31 #endif // ndef NO_NAMESPACE_GINAC
32
33 /** A pair of expressions.
34  *  This similar to, but slightly extended STL's pair<> but we need to account
35  *  for methods like .compare() */
36 class expair
37 {
38 public:
39     expair() {}
40     ~expair() {}
41     expair(const expair & other) : rest(other.rest), coeff(other.coeff)
42     {
43         GINAC_ASSERT(is_ex_exactly_of_type(coeff,numeric));
44     }
45     const expair & operator=(const expair & other)
46     {
47         if (this != &other) {
48             rest=other.rest;
49             coeff=other.coeff;
50         }
51         return *this;
52     }
53     expair(const ex & r, const ex & c) : rest(r), coeff(c)
54     {
55         GINAC_ASSERT(is_ex_exactly_of_type(coeff,numeric));
56     }
57     
58     bool is_numeric_with_coeff_1(void) const
59     {
60         GINAC_ASSERT(is_ex_exactly_of_type(coeff,numeric));
61         return is_ex_exactly_of_type(rest,numeric) &&
62                (coeff.is_equal(ex(1)));
63     }
64
65     bool is_equal(const expair & other) const
66     {
67         return (rest.is_equal(other.rest) && coeff.is_equal(other.coeff));
68     }
69     bool is_less(const expair & other) const 
70     {
71         return (rest.compare(other.rest)<0) ||
72                (!(other.rest.compare(rest)<0) && (coeff.compare(other.coeff)<0));
73     }
74     int compare(const expair & other) const
75     {
76         int cmpval=rest.compare(other.rest);
77         if (cmpval!=0) return cmpval;
78         cmpval=coeff.compare(other.coeff);
79         return cmpval;
80     }
81
82     bool is_less_old2(const expair & other) const 
83     {
84         /*
85         bool this_numeric_with_coeff_1=is_numeric_with_coeff_1();
86         bool other_numeric_with_coeff_1=other.is_numeric_with_coeff_1();
87         if (this_numeric_with_coeff_1) {
88             if (other_numeric_with_coeff_1) {
89                 // both have coeff 1: compare rests
90                 return rest.compare(other.rest)<0;
91             }
92             // only this has coeff 1: >
93             return false;
94         } else if (other_numeric_with_coeff_1) {
95             // only other has coeff 1: <
96             return true;
97         }
98         return (rest.compare(other.rest)<0) ||
99                (!(other.rest.compare(rest)<0) &&
100                  (coeff.compare(other.coeff)<0));
101         */
102         if (is_ex_exactly_of_type(rest,numeric) &&
103             is_ex_exactly_of_type(other.rest,numeric)) {
104             if (coeff.is_equal(ex(1))) {
105                 if ((other.coeff).is_equal(ex(1))) {
106                     // both have coeff 1: compare rests
107                     return rest.compare(other.rest)<0;
108                 }
109                 // only this has coeff 1: >
110                 return false;
111             } else if ((other.coeff).is_equal(ex(1))) {
112                 // only other has coeff 1: <
113                 return true;
114             }
115             // neither has coeff 1: usual compare        
116         }
117         return (rest.compare(other.rest)<0) ||
118                (!(other.rest.compare(rest)<0) &&
119                  (coeff.compare(other.coeff)<0));
120     }
121     int compare_old2(const expair & other) const
122     {
123         if (is_ex_exactly_of_type(rest,numeric) &&
124             is_ex_exactly_of_type(other.rest,numeric)) {
125             if ((coeff).is_equal(ex(1))) {
126                 if ((other.coeff).is_equal(ex(1))) {
127                     // both have coeff 1: compare rests
128                     return rest.compare(other.rest);
129                 }
130                 // only this has coeff 1: >
131                 return 1;
132             } else if ((other.coeff).is_equal(ex(1))) {
133                 // only other has coeff 1: <
134                 return -1;
135             }
136             // neither has coeff 1: usual compare        
137         }
138         /*
139         bool this_numeric_with_coeff_1=is_numeric_with_coeff_1();
140         bool other_numeric_with_coeff_1=other.is_numeric_with_coeff_1();
141         if (this_numeric_with_coeff_1) {
142             if (other_numeric_with_coeff_1) {
143                 // both have coeff 1: compare rests
144                 return rest.compare(other.rest);
145             }
146             // only this has coeff 1: >
147             return 1;
148         } else if (other_numeric_with_coeff_1) {
149             // only other has coeff 1: <
150             return -1;
151             // neither has coeff 1: usual compare        
152         }
153         */
154         int cmpval=rest.compare(other.rest);
155         if (cmpval!=0) return cmpval;
156         return coeff.compare(other.coeff);
157     }
158     bool is_less_old(const expair & other) const 
159     {
160         return (rest.compare(other.rest)<0) ||
161                (!(other.rest.compare(rest)<0) && (coeff.compare(other.coeff)<0));
162     }
163     int compare_old(const expair & other) const
164     {
165         int cmpval=rest.compare(other.rest);
166         if (cmpval!=0) return cmpval;
167         cmpval=coeff.compare(other.coeff);
168         return cmpval;
169     }
170
171     void printraw(ostream & os) const
172     {
173         os << "expair(";
174         rest.printraw(os);
175         os << ",";
176         coeff.printraw(os);
177         os << ")";
178     }
179
180     ex rest;
181     ex coeff;
182 };
183
184 class expair_is_less
185 {
186 public:
187     bool operator()(const expair & lh, const expair & rh) const
188     {
189         return lh.is_less(rh);
190     }
191 };
192
193 class expair_is_less_old
194 {
195 public:
196     bool operator()(const expair & lh, const expair & rh) const
197     {
198         return lh.is_less_old(rh);
199     }
200 };
201
202 #ifndef NO_NAMESPACE_GINAC
203 } // namespace GiNaC
204 #endif // ndef NO_NAMESPACE_GINAC
205
206 #endif // ndef __GINAC_EXPAIR_H__