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/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
<name>
Abstract:
<abstract>
Author:
Lev Nachmanson (levnach)
Revision History:
--*/
#pragma once
#include <string>
#include <vector>
#include <unordered_map>
#include "math/lp/lar_solver.h"
#include <iostream>
#include <fstream>
#include <functional>
#include <algorithm>
#include "math/lp/column.h"
#include "math/lp/lar_constraints.h"
#include <sstream>
#include <cstdlib>
namespace lp {
template<typename T>
T from_string(const std::string& str) {
std::istringstream ss(str);
T ret;
ss >> ret;
return ret;
}
class smt_reader {
public:
struct lisp_elem {
std::string m_head;
std::vector<lisp_elem> m_elems;
void print() {
if (!m_elems.empty()) {
std::cout << '(';
std::cout << m_head << ' ';
for (auto & el : m_elems)
el.print();
std::cout << ')';
} else {
std::cout << " " << m_head;
}
}
unsigned size() const { return static_cast<unsigned>(m_elems.size()); }
bool is_simple() const { return size() == 0; }
};
struct formula_constraint {
lconstraint_kind m_kind;
std::vector<std::pair<mpq, std::string>> m_coeffs;
mpq m_right_side;
void add_pair(mpq c, const std::string& name) {
m_coeffs.push_back(make_pair(c, name));
}
formula_constraint() : m_right_side(numeric_traits<mpq>::zero()) {}
};
lisp_elem m_formula_lisp_elem;
std::unordered_map<std::string, unsigned> m_name_to_var_index;
std::vector<formula_constraint> m_constraints;
bool m_is_OK;
unsigned m_line_number;
std::string m_file_name;
std::ifstream m_file_stream;
std::string m_line;
smt_reader(const std::string& file_name):
m_is_OK(true),
m_line_number(0),
m_file_name(file_name),
m_file_stream(file_name) {
}
void set_error() {
std::cout << "setting error" << std::endl;
m_is_OK = false;
}
bool is_ok() {
return m_is_OK;
}
bool prefix(const char * pr) {
return m_line.find(pr) == 0;
}
int first_separator() {
unsigned blank_pos = static_cast<unsigned>(m_line.find(' '));
unsigned br_pos = static_cast<unsigned>(m_line.find('('));
unsigned reverse_br_pos = static_cast<unsigned>(m_line.find(')'));
return std::min(blank_pos, std::min(br_pos, reverse_br_pos));
}
void fill_lisp_elem(lisp_elem & lm) {
if (m_line[0] == '(')
fill_nested_elem(lm);
else
fill_simple_elem(lm);
}
void fill_simple_elem(lisp_elem & lm) {
int separator = first_separator();
ENSURE(-1 != separator && separator != 0);
lm.m_head = m_line.substr(0, separator);
m_line = m_line.substr(separator);
}
void fill_nested_elem(lisp_elem & lm) {
ENSURE(m_line[0] == '(');
m_line = m_line.substr(1);
int separator = first_separator();
lm.m_head = m_line.substr(0, separator);
m_line = m_line.substr(lm.m_head.size());
eat_blanks();
while (!m_line.empty()) {
if (m_line[0] == '(') {
lisp_elem el;
fill_nested_elem(el);
lm.m_elems.push_back(el);
} else {
if (m_line[0] == ')') {
m_line = m_line.substr(1);
break;
}
lisp_elem el;
fill_simple_elem(el);
lm.m_elems.push_back(el);
}
eat_blanks();
}
}
void eat_blanks() {
while (!m_line.empty()) {
if (m_line[0] == ' ')
m_line = m_line.substr(1);
else
break;
}
}
void fill_formula_elem() {
fill_lisp_elem(m_formula_lisp_elem);
}
void parse_line() {
if (m_line.find(":formula") == 0) {
int first_br = static_cast<int>(m_line.find('('));
if (first_br == -1) {
std::cout << "empty formula" << std::endl;
return;
}
m_line = m_line.substr(first_br);
fill_formula_elem();
}
}
void set_constraint_kind(formula_constraint & c, lisp_elem & el) {
if (el.m_head == "=") {
c.m_kind = EQ;
} else if (el.m_head == ">=") {
c.m_kind = GE;
} else if (el.m_head == "<=") {
c.m_kind = LE;
} else if (el.m_head == ">") {
c.m_kind = GT;
} else if (el.m_head == "<") {
c.m_kind = LT;
} else {
std::cout << "kind " << el.m_head << " is not supported " << std::endl;
set_error();
}
}
void adjust_right_side(formula_constraint & /* c*/, lisp_elem & /*el*/) {
// ENSURE(el.m_head == "0"); // do nothing for the time being
}
void set_constraint_coeffs(formula_constraint & c, lisp_elem & el) {
ENSURE(el.m_elems.size() == 2);
set_constraint_coeffs_on_coeff_element(c, el.m_elems[0]);
adjust_right_side(c, el.m_elems[1]);
}
bool is_integer(std::string & s) {
if (s.empty()) return false;
// A signed char may be negative; isdigit accepts only unsigned-char values or EOF.
return atoi(s.c_str()) != 0 || isdigit(static_cast<unsigned char>(s.c_str()[0]));
}
void add_complex_sum_elem(formula_constraint & c, lisp_elem & el) {
if (el.m_head == "*") {
add_mult_elem(c, el.m_elems);
} else if (el.m_head == "~") {
lisp_elem & minel = el.m_elems[0];
ENSURE(minel.is_simple());
c.m_right_side += mpq(str_to_int(minel.m_head));
} else {
std::cout << "unexpected input " << el.m_head << std::endl;
set_error();
return;
}
}
std::string get_name(lisp_elem & name) {
ENSURE(name.is_simple());
ENSURE(!is_integer(name.m_head));
return name.m_head;
}
void add_mult_elem(formula_constraint & c, std::vector<lisp_elem> & els) {
ENSURE(els.size() == 2);
mpq coeff = get_coeff(els[0]);
std::string col_name = get_name(els[1]);
c.add_pair(coeff, col_name);
}
mpq get_coeff(lisp_elem & le) {
if (le.is_simple()) {
return mpq(str_to_int(le.m_head));
} else {
ENSURE(le.m_head == "~");
ENSURE(le.size() == 1);
lisp_elem & el = le.m_elems[0];
ENSURE(el.is_simple());
return -mpq(str_to_int(el.m_head));
}
}
int str_to_int(std::string & s) {
ENSURE(is_integer(s));
return atoi(s.c_str());
}
void add_sum_elem(formula_constraint & c, lisp_elem & el) {
if (el.size()) {
add_complex_sum_elem(c, el);
} else {
ENSURE(is_integer(el.m_head));
int v = atoi(el.m_head.c_str());
mpq vr(v);
c.m_right_side -= vr;
}
}
void add_sum(formula_constraint & c, std::vector<lisp_elem> & sum_els) {
for (auto & el : sum_els)
add_sum_elem(c, el);
}
void set_constraint_coeffs_on_coeff_element(formula_constraint & c, lisp_elem & el) {
if (el.m_head == "*") {
add_mult_elem(c, el.m_elems);
} else if (el.m_head == "+") {
add_sum(c, el.m_elems);
} else {
UNREACHABLE(); // unexpected input
}
}
void create_constraint(lisp_elem & el) {
formula_constraint c;
set_constraint_kind(c, el);
set_constraint_coeffs(c, el);
m_constraints.push_back(c);
}
void fill_constraints() {
if (m_formula_lisp_elem.m_head != "and") {
std::cout << "unexpected top element " << m_formula_lisp_elem.m_head << std::endl;
set_error();
return;
}
for (auto & el : m_formula_lisp_elem.m_elems)
create_constraint(el);
}
void read() {
if (!m_file_stream.is_open()){
std::cout << "cannot open file " << m_file_name << std::endl;
set_error();
return;
}
while (m_is_OK && getline(m_file_stream, m_line)) {
parse_line();
m_line_number++;
}
m_file_stream.close();
fill_constraints();
}
/*
void fill_lar_solver_on_row(row * row, lar_solver *solver) {
if (row->m_name != m_cost_row_name) {
lar_constraint c(get_lar_relation_from_row(row->m_type), row->m_right_side);
for (auto s : row->m_row_columns) {
var_index i = solver->add_var(s.first);
c.add_variable_to_constraint(i, s.second);
}
solver->add_constraint(&c);
} else {
// ignore the cost row
}
}
void fill_lar_solver_on_rows(lar_solver * solver) {
for (auto row_it : m_rows) {
fill_lar_solver_on_row(row_it.second, solver);
}
}
void create_low_constraint_for_var(column* col, bound * b, lar_solver *solver) {
lar_constraint c(GE, b->m_low);
var_index i = solver->add_var(col->m_name);
c.add_variable_to_constraint(i, numeric_traits<T>::one());
solver->add_constraint(&c);
}
void create_upper_constraint_for_var(column* col, bound * b, lar_solver *solver) {
lar_constraint c(LE, b->m_upper);
var_index i = solver->add_var(col->m_name);
c.add_variable_to_constraint(i, numeric_traits<T>::one());
solver->add_constraint(&c);
}
void create_equality_constraint_for_var(column* col, bound * b, lar_solver *solver) {
lar_constraint c(EQ, b->m_fixed_value);
var_index i = solver->add_var(col->m_name);
c.add_variable_to_constraint(i, numeric_traits<T>::one());
solver->add_constraint(&c);
}
void fill_lar_solver_on_columns(lar_solver * solver) {
for (auto s : m_columns) {
mps_reader::column * col = s.second;
solver->add_var(col->m_name);
auto b = col->m_bound;
if (b == nullptr) return;
if (b->m_free) continue;
if (b->m_low_is_set) {
create_low_constraint_for_var(col, b, solver);
}
if (b->m_upper_is_set) {
create_upper_constraint_for_var(col, b, solver);
}
if (b->m_value_is_fixed) {
create_equality_constraint_for_var(col, b, solver);
}
}
}
*/
unsigned register_name(const std::string& s) {
auto it = m_name_to_var_index.find(s);
if (it!= m_name_to_var_index.end())
return it->second;
unsigned ret = static_cast<unsigned>(m_name_to_var_index.size());
m_name_to_var_index[s] = ret;
return ret;
}
void add_constraint_to_solver(lar_solver * solver, formula_constraint & fc, unsigned i) {
vector<std::pair<mpq, lpvar>> ls;
for (auto & it : fc.m_coeffs) {
ls.push_back(std::make_pair(it.first, solver->add_var(register_name(it.second), false)));
}
unsigned j = solver->add_term(ls, i);
solver->add_var_bound(j, fc.m_kind, fc.m_right_side);
}
void fill_lar_solver(lar_solver * solver) {
unsigned i = 0;
for (formula_constraint & fc : m_constraints)
add_constraint_to_solver(solver, fc, i++);
}
lar_solver * create_lar_solver() {
lar_solver * ls = new lar_solver();
fill_lar_solver(ls);
return ls;
}
};
}