geneticengine.grammar.metahandlers.smt

Submodules

• geneticengine.grammar.metahandlers.smt.lang
• geneticengine.grammar.metahandlers.smt.parser

Attributes

p_expr

Classes

Grammar
RandomSource	Helper class that provides a standard way to create an ABC using
MetaHandlerGenerator	MetaHandlers are type refinements.
SMT	MetaHandlers are type refinements.

Functions

is_metahandler(ty)	Returns if type is a metahandler. AnnotatedType[int, IntRange(3,10)] is
simplify_type(t)

Package Contents

class geneticengine.grammar.metahandlers.smt.Grammar(starting_symbol, considered_subtypes=None, expansion_depthing=False)

Parameters:

• starting_symbol (type)

• considered_subtypes (list[type] | None)

• expansion_depthing (bool)

starting_symbol: type

alternatives: dict[type, list[type]]

distanceToTerminal: dict[Any, int]

all_nodes: set[type]

recursive_prods: set[type]

terminals: set[type]

non_terminals: set[type]

abstract_dist_to_t: dict[type, dict[type, int]]

considered_subtypes = []

expansion_depthing = False

validate()

register_alternative(nonterminal, nodetype)

Register a production A->B Call multiple times with same A to register many possible alternatives.

Parameters:

• nonterminal (type)

• nodetype (type)

register_type(ty)

Parameters:

ty (type)

__repr__()

get_all_symbols()

All symbols in the current grammar, including terminals.

Return type:

tuple[set[type], set[type], set[type]]

collect_types(ty)

Parameters:

ty (type)

get_all_mentioned_symbols()

Return type:

set[type]

get_distance_to_terminal(ty)

Returns the current distance to terminal of a given type.

Parameters:

ty (type)

Return type:

int

get_min_tree_depth()

Returns the minimum depth a tree must have.

get_max_node_depth()

Returns the maximum minimum depth a node can have.

preprocess()

Computes distanceToTerminal via a fixpoint algorithm.

Return type:

None

get_weights()

update_weights(learning_rate, extra_weights)

is_reachable(t1, t2)

Parameters:

• t1 (Type)

• t2 (Type)

Return type:

bool

reaches_leaf(t, visited=None)

Returns whether a given type reaches a leaf type, or None if it causes a loop.

Loops should be ignored only if there is an alternative path.

Parameters:

• t (Type)

• visited (set | None)

Return type:

bool | None

usable_grammar()

Returns a subset of the grammar that is actually reachable.

Return type:

Grammar

get_grammar_properties_summary()

Returns a summary of grammar properties:

• A depth range (minimum depth and maximum depth of the grammar)

• The number of Non-Terminal symbols in the grammar

• A summary of production statistics:

  • Frequency of Productions in the Right Hand side

  • The number of recursive productions

  • Per non-terminal, all the alternative productions

  • The total number of productions

  • The average number of productions per non-terminal

  • The average non-terminals per production for each non-terminal

Return type:

GrammarSummary

geneticengine.grammar.metahandlers.smt.is_metahandler(ty)

Returns if type is a metahandler. AnnotatedType[int, IntRange(3,10)] is an example of a Metahandler.

Verification is done using the __metadata__, which is the first argument of Annotated

Parameters:

ty (type)

Return type:

bool

class geneticengine.grammar.metahandlers.smt.RandomSource

Bases: abc.ABC

Helper class that provides a standard way to create an ABC using inheritance.

abstractmethod randint(min, max)

Parameters:

• min (int)

• max (int)

Return type:

int

abstractmethod random_float(min, max)

Parameters:

• min (float)

• max (float)

Return type:

float

choice(choices)

Parameters:

choices (list[T])

Return type:

T

choice_weighted(choices, weights)

Parameters:

• choices (list[T])

• weights (list[float])

Return type:

T

shuffle(lst)

Parameters:

lst (list[T])

pop_random(lst)

Parameters:

lst (list[T])

Return type:

T

random_bool()

Return type:

bool

normalvariate(mean, sigma)

Parameters:

• mean (float)

• sigma (float)

Return type:

float

class geneticengine.grammar.metahandlers.smt.MetaHandlerGenerator

Bases: abc.ABC

MetaHandlers are type refinements.

They override the generation procedure of the base type.

abstractmethod validate(Any)

Return type:

bool

abstractmethod generate(random, grammar, base_type, rec, dependent_values, parent_values)

Generates an instance of type base_type, according to some criterion.

Parameters:

• r (Source) – Random source for generation

• g (Grammar) – Grammar to follow in the generation :param Callable[[int, Type], Any] rec: The method to generate a new instance of type and maximum depth d

• depth (int) – the current depth budget

• base_type (Type) – The inner type being annotated

• argname (str) – The name of the field of the parent object which is being generated :param Dict[str, Type] context: The names and types of all fields in the parent object :param Dict[str, Type] dependent_values: The names and values of all previous fields in the parent object

• random (geneticengine.random.sources.RandomSource)

• grammar (geneticengine.grammar.grammar.Grammar)

• rec (Callable[[type[T]], T])

• dependent_values (dict[str, Any])

• parent_values (list[dict[str, Any]])

Return type:

Any

get_dependencies()

geneticengine.grammar.metahandlers.smt.p_expr

geneticengine.grammar.metahandlers.smt.simplify_type(t)

Parameters:

t (type)

Return type:

type

class geneticengine.grammar.metahandlers.smt.SMT(restriction_as_str='true==true')

Bases: geneticengine.grammar.metahandlers.base.MetaHandlerGenerator

MetaHandlers are type refinements.

They override the generation procedure of the base type.

restriction_as_str = 'true==true'

restriction

validate(v)

Return type:

bool

generate(random, grammar, base_type, rec, dependent_values, parent_values)

Generates an instance of type base_type, according to some criterion.

Parameters:

• r (Source) – Random source for generation

• g (Grammar) – Grammar to follow in the generation :param Callable[[int, Type], Any] rec: The method to generate a new instance of type and maximum depth d

• depth (int) – the current depth budget

• base_type (Type) – The inner type being annotated

• argname (str) – The name of the field of the parent object which is being generated :param Dict[str, Type] context: The names and types of all fields in the parent object :param Dict[str, Type] dependent_values: The names and values of all previous fields in the parent object

• random (geneticengine.random.sources.RandomSource)

• grammar (geneticengine.grammar.grammar.Grammar)

• rec (Any)

• dependent_values (dict[str, Any])

• parent_values (list[dict[str, Any]])

__repr__()