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
use super::LanguageParser;
use cnvx_core::{LinExpr, Model, Objective, VarId};
use std::collections::HashMap;
#[derive(Default)]
pub struct MPSLanguage;
impl MPSLanguage {
pub fn new() -> Self {
Self {}
}
}
impl LanguageParser for MPSLanguage {
fn parse(&self, src: &str) -> Result<Model, String> {
let mut model = Model::new();
let mut section = "";
let mut rows: HashMap<String, char> = HashMap::new();
let mut col_exprs: HashMap<String, LinExpr> = HashMap::new();
let mut rhs_map: HashMap<String, f64> = HashMap::new();
let mut var_map: HashMap<String, VarId> = HashMap::new();
for raw in src.lines() {
let line = raw.trim();
if line.is_empty() {
continue;
}
if line.eq_ignore_ascii_case("ROWS") {
section = "ROWS";
continue;
} else if line.eq_ignore_ascii_case("COLUMNS") {
section = "COLUMNS";
continue;
} else if line.eq_ignore_ascii_case("RHS") {
section = "RHS";
continue;
} else if line.eq_ignore_ascii_case("BOUNDS") {
section = "BOUNDS";
continue;
} else if line.eq_ignore_ascii_case("ENDATA") {
break;
}
match section {
"ROWS" => {
let parts: Vec<_> = line.split_whitespace().collect();
if parts.len() >= 2 {
if parts[0].ends_with('.') && parts.len() >= 3 {
let rtype = parts[1].chars().next().unwrap_or(' ');
let name = parts[2].to_string();
rows.insert(name, rtype);
} else {
let rtype = parts[0].chars().next().unwrap_or(' ');
let name = parts[1].to_string();
rows.insert(name, rtype);
}
}
}
"COLUMNS" => {
let parts: Vec<_> = line.split_whitespace().collect();
if parts.len() < 2 {
continue;
}
let mut idx = 0;
if parts[0].ends_with('.') && parts.len() >= 2 {
idx = 1;
}
if parts.len() <= idx {
continue;
}
let col = parts[idx].to_string();
let varid = *var_map
.entry(col.clone())
.or_insert_with(|| model.add_var().finish());
let mut i = idx + 1;
while i + 1 < parts.len() {
let row = parts[i].to_string();
let val = parts[i + 1].parse::<f64>().map_err(|_| {
format!("invalid number in COLUMNS: {}", parts[i + 1])
})?;
let entry = col_exprs
.entry(row.clone())
.or_insert(LinExpr::constant(0.0));
*entry += LinExpr::new(varid, val);
i += 2;
}
}
"RHS" => {
let parts: Vec<_> = line.split_whitespace().collect();
if parts.len() < 3 {
continue;
}
let mut idx = 0;
if parts[0].ends_with('.') && parts.len() >= 2 {
idx = 1;
}
let mut i = idx + 1;
while i + 1 < parts.len() {
let row = parts[i].to_string();
let val = parts[i + 1].parse::<f64>().map_err(|_| {
format!("invalid number in RHS: {}", parts[i + 1])
})?;
rhs_map.insert(row, val);
i += 2;
}
}
"BOUNDS" => {
let parts: Vec<_> = line.split_whitespace().collect();
if parts.len() < 3 {
continue;
}
let mut idx = 0;
if parts[0].ends_with('.') && parts.len() >= 2 {
idx = 1;
}
let btype = parts[idx];
if parts.len() <= idx + 2 {
continue;
}
let varname = parts[idx + 2].to_string();
let varid = *var_map
.entry(varname.clone())
.or_insert_with(|| model.add_var().finish());
match btype {
"UP" => {
if parts.len() >= idx + 4
&& let Ok(v) = parts[idx + 3].parse::<f64>()
{
model.vars[varid.0].ub = Some(v);
}
}
"LO" => {
if parts.len() >= idx + 4
&& let Ok(v) = parts[idx + 3].parse::<f64>()
{
model.vars[varid.0].lb = Some(v);
}
}
"FR" => {
model.vars[varid.0].lb = None;
model.vars[varid.0].ub = None;
}
"MI" => {
model.vars[varid.0].lb = None;
}
"BV" => {
model.vars[varid.0].is_integer = true;
model.vars[varid.0].lb = Some(0.0);
model.vars[varid.0].ub = Some(1.0);
}
"FX" => {
if parts.len() >= idx + 4
&& let Ok(v) = parts[idx + 3].parse::<f64>()
{
model.vars[varid.0].lb = Some(v);
model.vars[varid.0].ub = Some(v);
}
}
_ => {}
}
}
_ => {}
}
}
for (rname, rtype) in &rows {
let expr = col_exprs.get(rname).cloned().unwrap_or(LinExpr::constant(0.0));
let rhs = *rhs_map.get(rname).unwrap_or(&0.0);
match *rtype {
'N' => {
model.add_objective(Objective::minimize(expr).name("Z"));
}
'L' => {
model += expr.leq(rhs);
}
'G' => {
model += expr.geq(rhs);
}
'E' => {
model += expr.eq(rhs);
}
_ => {}
}
}
Ok(model)
}
}