from __future__ import annotations
from dataclasses import dataclass
from typing import TYPE_CHECKING, Any, Optional, Union
import gamspy._algebra.condition as condition
import gamspy._algebra.domain as domain
import gamspy._algebra.operable as operable
import gamspy._algebra.operation as operation
import gamspy._validation as validation
import gamspy.utils as utils
from gamspy._extrinsic import ExtrinsicFunction
from gamspy._symbols.implicits.implicit_symbol import ImplicitSymbol
from gamspy._symbols.symbol import Symbol
from gamspy.exceptions import ValidationError
from gamspy.math.misc import MathOp
if TYPE_CHECKING:
import gamspy._algebra.expression as expression
from gamspy import Alias, Set
from gamspy._algebra.operation import Operation
OperandType = Optional[
Union[
int,
float,
str,
Symbol,
ImplicitSymbol,
Operation,
expression.Expression,
MathOp,
]
]
GMS_MAX_LINE_LENGTH = 80000
LINE_LENGTH_OFFSET = 79000
@dataclass
class DomainPlaceHolder:
indices: list[tuple[str, int]]
[docs]
class Expression(operable.Operable):
"""
Expression of two operands and an operation.
Parameters
----------
left: str | int | float | Parameter | Variable | None
Left operand
data: str
Operation
right: str | int | float | Parameter | Variable | None
Right operand
Examples
--------
>>> import gamspy as gp
>>> m = gp.Container()
>>> a = gp.Parameter(m, name="a")
>>> b = gp.Parameter(m, name="b")
>>> expression = a * b
>>> expression.gamsRepr()
'(a * b)'
"""
def __init__(
self,
left: OperandType,
data: str | MathOp | ExtrinsicFunction,
right: OperandType,
):
self.left = (
utils._map_special_values(left)
if isinstance(left, float)
else left
)
self.data = data
self.right = (
utils._map_special_values(right)
if isinstance(right, float)
else right
)
if data == "=" and isinstance(right, Expression):
right._fix_equalities()
self.representation = self._create_output_str()
self.where = condition.Condition(self)
self._create_domain()
left_control = getattr(left, "controlled_domain", [])
right_control = getattr(right, "controlled_domain", [])
self.controlled_domain: list[Set | Alias] = list(
set([*left_control, *right_control])
)
self.container = None
if left is not None and hasattr(left, "container"):
self.container = left.container
elif right is not None and hasattr(right, "container"):
self.container = right.container
def _create_domain(self):
for loc, result in [
(self.left, "_left_domain"),
(self.right, "_right_domain"),
]:
if isinstance(loc, condition.Condition):
loc = loc.conditioning_on
if loc is None or isinstance(loc, (int, float, str)):
result_domain = [] # left is a scalar
elif isinstance(loc, domain.Domain):
result_domain = loc.sets
else:
result_domain = loc.domain
setattr(self, result, result_domain)
left_domain = self._left_domain
right_domain = self._right_domain
set_to_index = {}
for domain_char, domain_ptr in (
("l", left_domain),
("r", right_domain),
):
for i, d in enumerate(domain_ptr):
if isinstance(d, str):
continue # string domains are fixed and they do not count
if d not in set_to_index:
set_to_index[d] = []
set_to_index[d].append((domain_char, i))
shadow_domain = []
result_domain = []
for d in [*left_domain, *right_domain]:
if isinstance(d, str):
continue
if d not in result_domain:
result_domain.append(d)
indices = set_to_index[d]
shadow_domain.append(DomainPlaceHolder(indices=indices))
self._shadow_domain = shadow_domain
self.domain = result_domain
self.dimension = validation.get_dimension(self.domain)
def __getitem__(self, indices):
indices = validation.validate_domain(self, indices)
left_domain = [d for d in self._left_domain]
right_domain = [d for d in self._right_domain]
for i, s in enumerate(indices):
for lr, pos in self._shadow_domain[i].indices:
if lr == "l":
left_domain[pos] = s
else:
right_domain[pos] = s
left = self.left[left_domain] if left_domain else self.left
right = self.right[right_domain] if right_domain else self.right
return Expression(left, self.data, right)
def _get_operand_representations(self) -> tuple[str, str]:
left_str, right_str = "", ""
if self.left is not None:
left_str = (
str(self.left)
if isinstance(self.left, (int, float, str))
else self.left.gamsRepr()
)
if self.right is not None:
right_str = (
str(self.right)
if isinstance(self.right, (int, float, str))
else self.right.gamsRepr()
)
# ((((ord(n) - 1) / 10) * -1) + ((ord(n) / 10) * 0)); -> not valid
# ((((ord(n) - 1) / 10) * (-1)) + ((ord(n) / 10) * 0)); -> valid
if isinstance(self.left, (int, float)) and self.left < 0:
left_str = f"({left_str})"
if isinstance(self.right, (int, float)) and self.right < 0:
right_str = f"({right_str})"
# (voycap(j,k)$vc(j,k)) .. sum(.) -> not valid
# voycap(j,k)$vc(j,k) .. sum(.) -> valid
if self.data in ["..", "="] and isinstance(
self.left, condition.Condition
):
left_str = left_str[1:-1]
return left_str, right_str
def _create_output_str(self) -> str:
left_str, right_str = self._get_operand_representations()
# get around 80000 line length limitation in GAMS
length = len(left_str) + len(self.data) + len(right_str)
if length >= GMS_MAX_LINE_LENGTH - LINE_LENGTH_OFFSET:
out_str = f"{left_str} {self.data}\n {right_str}"
else:
out_str = f"{left_str} {self.data} {right_str}"
if self.data in ["..", "="]:
return f"{out_str};"
if self.data in ["=g=", "=l=", "=e=", "=n=", "=x=", "=c=", "=b="]:
return out_str
return f"({out_str})"
def __eq__(self, other): # type: ignore
return Expression(self, "=e=", other)
def __ne__(self, other): # type: ignore
return Expression(self, "ne", other)
def __neg__(self):
return Expression(None, "-", self)
def __bool__(self):
raise ValidationError(
"An expression cannot be used as a truth value. If you are "
"trying to generate an expression, use binary operators "
"instead (e.g. &, |, ^). For more details, see: "
"https://gamspy.readthedocs.io/en/latest/user/gamspy_for_gams_users.html#logical-operations"
)
def __repr__(self) -> str:
return f"Expression(left={self.left}, data={self.data}, right={self.right})"
def _replace_operator(self, operator: str):
self.data = operator
self.representation = self._create_output_str()
[docs]
def latexRepr(self) -> str:
"""
Representation of this Expression in Latex.
Returns
-------
str
"""
data_map = {
"=g=": "\\geq",
"=l=": "\\leq",
"=e=": "=",
"*": "\\cdot",
"and": "\\wedge",
"or": "\\vee",
"xor": "\\oplus",
"$": "|",
}
if isinstance(self.left, float):
self.left = utils._map_special_values(self.left)
if isinstance(self.right, float):
self.right = utils._map_special_values(self.right)
if self.left is None:
left_str = ""
else:
left_str = (
str(self.left)
if isinstance(self.left, (int, float, str))
else self.left.latexRepr()
)
if self.right is None:
right_str = ""
else:
right_str = (
str(self.right)
if isinstance(self.right, (int, float, str))
else self.right.latexRepr()
)
data = self.data
if isinstance(self.data, str):
data = data_map.get(self.data, self.data)
data_str = (
str(data)
if isinstance(data, (int, float, str))
else data.latexRepr()
)
if self.data == "/":
return f"\\frac{{{left_str}}}{{{right_str}}}"
return f"{left_str} {data_str} {right_str}"
[docs]
def gamsRepr(self) -> str:
"""
Representation of this Expression in GAMS language.
Returns
-------
str
Examples
--------
>>> import gamspy as gp
>>> m = gp.Container()
>>> a = gp.Parameter(m, name="a")
>>> b = gp.Parameter(m, name="b")
>>> expression = a * b
>>> expression.gamsRepr()
'(a * b)'
"""
return self.representation
[docs]
def getDeclaration(self) -> str:
"""
Declaration of the Expression in GAMS
Returns
-------
str
Examples
--------
>>> import gamspy as gp
>>> m = gp.Container()
>>> a = gp.Parameter(m, name="a")
>>> b = gp.Parameter(m, name="b")
>>> expression = a * b
>>> expression.getDeclaration()
'(a * b)'
"""
return self.gamsRepr()
def _fix_equalities(self) -> None:
# Equality operations on Parameter and Variable objects generate
# GAMS equality signs: =g=, =e=, =l=. If these signs appear on
# assignments, replace them with regular equality ops.
EQ_MAP: dict[Any, str] = {"=g=": ">=", "=e=": "eq", "=l=": "<="}
stack = []
node = self
while True:
if node is not None:
stack.append(node)
node = getattr(node, "left", None) # type: ignore
elif stack:
node = stack.pop()
if isinstance(node, Expression) and node.data in EQ_MAP:
node._replace_operator(EQ_MAP[node.data])
if isinstance(node, operation.Operation) and isinstance(
node.rhs, Expression
):
node.rhs._fix_equalities()
node = getattr(node, "right", None)
else:
break # pragma: no cover
self.representation = self._create_output_str()
def _find_all_symbols(self) -> list[str]:
symbols: list[str] = []
stack = []
node = self
while True:
if node is not None:
stack.append(node)
node = getattr(node, "left", None) # type: ignore
elif stack:
node = stack.pop()
if isinstance(node, ImplicitSymbol):
stack.append(node.parent)
if isinstance(node, (ImplicitSymbol, Symbol)):
for index, elem in enumerate(node.domain):
if isinstance(elem, (Symbol, ImplicitSymbol)):
path = validation.get_domain_path(elem)
for name in path:
if name not in symbols and " " not in name:
symbols.append(name)
if (
isinstance(node, ImplicitSymbol)
and isinstance(elem, str)
and elem != "*"
):
symbol = node.parent.domain[index]
if (
not isinstance(symbol, str)
and symbol.name not in symbols
):
symbols.append(symbol.name)
if node.name not in symbols:
symbols.append(node.name)
elif isinstance(node, Expression) and isinstance(
node.data, MathOp
):
stack += list(node.data.elements)
if isinstance(node, operation.Operation):
stack += node.op_domain
node = node.rhs
elif isinstance(node, condition.Condition):
stack.append(node.conditioning_on)
node = node.condition
else:
node = getattr(node, "right", None)
else:
break # pragma: no cover
return symbols
def _find_symbols_in_conditions(self) -> list[str]:
symbols: list[str] = []
stack = []
node = self
while True:
if node is not None:
stack.append(node)
node = getattr(node, "left", None) # type: ignore
elif stack:
node = stack.pop()
if isinstance(node, condition.Condition):
given_condition = node.condition
if isinstance(given_condition, Expression):
symbols += given_condition._find_all_symbols()
elif isinstance(given_condition, ImplicitSymbol):
symbols.append(given_condition.parent.name)
if isinstance(node, operation.Operation):
stack += node.op_domain
node = node.rhs
else:
node = getattr(node, "right", None)
else:
break # pragma: no cover
return symbols
def _validate_definition(self, control_stack):
stack = []
node = self.right
while True:
if node is not None:
stack.append(node)
node = getattr(node, "left", None) # type: ignore
elif stack:
node = stack.pop()
if isinstance(node, operation.Operation):
node.validate_operation(control_stack)
for elem in node.raw_domain:
if elem in control_stack:
raise ValidationError(
f"Set `{elem}` is already in control!"
)
elif isinstance(node, ImplicitSymbol):
for elem in node.domain:
if (
isinstance(elem, Symbol)
and elem not in control_stack
):
raise ValidationError(
f"Uncontrolled set `{elem}` entered as constant!"
)
elif (
isinstance(elem, ImplicitSymbol)
and elem.parent not in control_stack
):
raise ValidationError(
f"Uncontrolled set `{elem.parent}` entered as constant!"
)
node = getattr(node, "right", None)
else:
break # pragma: no cover
