raesl.compile.ast.exprs

Expressions to store and reason about values and boundaries.

Module Contents

Classes

DataValue	Some kind of data value. Do not use this, but use a derived class instead.
Value	A value with an optional unit. Don't modify these objects in-place, create a new
VariableValue	Class representing a variable or parameter as value.
Expression	Base class of an expression.
Comparison	Class storing a comparison.
RelationComparison	A relation between a variable and either a value or a variable.
ObjectiveComparison	An intended direction for a variable. Note that the 'maximize' parameter
Disjunction	Disjunctive expression (also known as 'or' expression).

Attributes

_MATH_OP_TRANSLATE

class raesl.compile.ast.exprs.DataValue

Some kind of data value. Do not use this, but use a derived class instead.

abstract get_units() → Set[str] | None

Obtain the units of the value. Gives a set of names without square brackets where lack of units results in the empty set, and not supporting units gives None.

Returns:

Names of the available units without square brackets or None.

class raesl.compile.ast.exprs.Value(value: raesl.compile.scanner.Token, unit: raesl.compile.scanner.Token | None = None)

Bases: DataValue

A value with an optional unit. Don’t modify these objects in-place, create a new object instead.

Parameters:

• value – Stored value as text.

• unit – Either None or text describing the unit. Treat as read-only, as changing it may break the cache.

_unit_cache

Units of the literal after normalizing self.unit. Computed on demand.

get_units() → Set[str] | None

Obtain the units of the value. Gives a set of names without square brackets where lack of units results in the empty set, and not supporting units gives None.

Returns:

Names of the available units without square brackets or None.

__eq__(other)

Return self==value.

__repr__()

Return repr(self).

class raesl.compile.ast.exprs.VariableValue(var_tok: raesl.compile.scanner.Token)

Bases: DataValue

Class representing a variable or parameter as value.

Parameters:

• var_tok – Token stating the possibly dotted name of the variable.

• var_node – If not None, the node represented by the object. Set during type checking.

get_units() → Set[str] | None

Obtain the units of the value. Gives a set of names without square brackets where lack of units results in the empty set, and not supporting units gives None.

Returns:

Names of the available units without square brackets or None.

class raesl.compile.ast.exprs.Expression

Base class of an expression.

class raesl.compile.ast.exprs.Comparison(is_constraint: bool)

Bases: Expression

Class storing a comparison.

Parameters:

is_constraint – Whether the comparison is considered to be a constraint rather than a requirement.

raesl.compile.ast.exprs._MATH_OP_TRANSLATE

class raesl.compile.ast.exprs.RelationComparison(is_constraint: bool, lhs_var: VariableValue, isaux_tok: raesl.compile.scanner.Token, cmp_tok: raesl.compile.scanner.Token, rhs_varval: DataValue)

Bases: Comparison

A relation between a variable and either a value or a variable.

Parameters:

• is_constraint – Whether the comparison is considered to be a constraint rather than a requirement.

• lhs_var – Left hand side variable being compared.

• isaux_tok – ‘is’ for a constraint, else the aux word for expressing strength of the comparison.

• cmp_tok – One of the key words that expression the comparison to perform.

• math_compare – Translated ‘cmp_tok’, with the ascii math text.

• rhs_varval – Right hand side variable or value.

get_location() → raesl.types.Location

Return a location to point at the comparison for error reporting purposes.

class raesl.compile.ast.exprs.ObjectiveComparison(lhs_var: VariableValue, aux_tok: raesl.compile.scanner.Token, maximize: bool)

Bases: Comparison

An intended direction for a variable. Note that the ‘maximize’ parameter controls both the ‘maximize’ and ‘minimize’ desires.

Parameters:

• lhs_var – Variable with the objective.

• aux_tok – One of the auxiliary verbs expressing strength of the objective.

• maximize – If set the comparison expresses the desire to maximize the variable.

minimize

Opposite of maximize.

property minimize: bool

get_location() → raesl.types.Location

Return a location to point at the comparison for error reporting purposes.

class raesl.compile.ast.exprs.Disjunction(childs: Sequence[Expression])

Bases: Expression

Disjunctive expression (also known as ‘or’ expression). It is true iff at least one of it child expressions is true.

Parameters:

childs – Child expressions of the disjunction. It is recommended to have at least two children in an object.