diff --git a/mathics/builtin/trace.py b/mathics/builtin/trace.py index 51366faa2..eb5968045 100644 --- a/mathics/builtin/trace.py +++ b/mathics/builtin/trace.py @@ -33,7 +33,9 @@ from mathics.core.symbols import SymbolFalse, SymbolNull, SymbolTrue, strip_context -def traced_apply_rule(self, expression, vars, options: dict, evaluation: Evaluation): +def traced_apply_function( + self, expression, vars, options: dict, evaluation: Evaluation +): if options and self.check_options: if not self.check_options(options, evaluation): return None @@ -185,7 +187,7 @@ class TraceBuiltins(_TraceBase): """ definitions_copy: Definitions - apply_rule_copy: Callable + apply_function_copy: Callable function_stats: "defaultdict" = defaultdict( lambda: {"count": 0, "elapsed_milliseconds": 0.0} @@ -238,19 +240,19 @@ def sort_by_name(tup: tuple): @staticmethod def enable_trace(evaluation) -> None: if TraceBuiltins.traced_definitions is None: - TraceBuiltins.apply_rule_copy = BuiltinRule.apply_rule + TraceBuiltins.apply_function_copy = BuiltinRule.apply_function TraceBuiltins.definitions_copy = evaluation.definitions - # Replaces apply_rule by the custom one - BuiltinRule.apply_rule = traced_apply_rule - # Create new definitions uses the new apply_rule + # Replaces apply_function by the custom one + BuiltinRule.apply_function = traced_apply_function + # Create new definitions uses the new apply_function evaluation.definitions = Definitions(add_builtin=True) else: evaluation.definitions = TraceBuiltins.definitions_copy @staticmethod def disable_trace(evaluation) -> None: - BuiltinRule.apply_rule = TraceBuiltins.apply_rule_copy + BuiltinRule.apply_function = TraceBuiltins.apply_function_copy evaluation.definitions = TraceBuiltins.definitions_copy def eval(self, expr, evaluation, options={}): diff --git a/mathics/core/rules.py b/mathics/core/rules.py index dc1c12c5b..6823f29b1 100644 --- a/mathics/core/rules.py +++ b/mathics/core/rules.py @@ -1,6 +1,15 @@ -# cython: language_level=3 # -*- coding: utf-8 -*- +"""Rules are a core part of the way WMA and Mathics3 executes a +program. Expressions can be transformed by rewrite rules (AKA +transformation rules); builtin functions get matched and applied via a +function signature specified using a BuiltinRule. +This module contains the classes for these two types of rules. + +""" + + +from abc import ABC from inspect import signature from itertools import chain from typing import Callable, Optional @@ -21,21 +30,24 @@ def function_arguments(f): class StopGenerator_BaseRule(StopGenerator): + """ + Signals that there are no more rules to check for pattern matching + """ + pass -class BaseRule(KeyComparable): +class BaseRule(KeyComparable, ABC): """ - This is the base class from which all other Rules are derived from. + This is the base class from which BuiltinRule and Rule classes + are derived from. - Rules are part of the rewriting system of Mathics. See + Rules are part of the rewriting system of Mathics3. See https://en.wikipedia.org/wiki/Rewriting This class is not complete in of itself and subclasses should - adapt or fill in what is needed. In particular ``apply_rule()`` - needs to be implemented. - - Important subclasses: BuiltinRule and Rule. + adapt or fill in what is needed. In particular either ``apply_rule()`` + or ``apply_function()`` need to be implemented. Note: we want Rules to be serializable so that we can dump and restore Rules in order to make startup time faster. @@ -75,7 +87,12 @@ def yield_match(vars, rest): if name.startswith("_option_"): options[name[len("_option_") :]] = value del vars[name] - new_expression = self.apply_rule(expression, vars, options, evaluation) + apply_fn = ( + self.apply_function + if isinstance(self, BuiltinRule) + else self.apply_rule + ) + new_expression = apply_fn(expression, vars, options, evaluation) if new_expression is None: new_expression = expression if rest[0] or rest[1]: @@ -123,17 +140,22 @@ def yield_match(vars, rest): def apply_rule(self): raise NotImplementedError + def apply_function(self): + raise NotImplementedError + def get_sort_key(self) -> tuple: # FIXME: check if this makes sense: return tuple((self.system, self.pattern.get_sort_key(True))) +# FIXME: the class name would be better called RewiteRule. class Rule(BaseRule): - """There are two kinds of Rules. This kind of Rule transforms an - Expression into another Expression based on the pattern and a - replacement term and doesn't involve function application. + """There are two kinds of Rules. This kind of is a rewrite rule + and transforms an Expression into another Expression based on the + pattern and a replacement term and doesn't involve function + application. - Also, in contrast to BuiltinRule[], rule application cannot force + In contrast to BuiltinRule[], rule application cannot force a reevaluation of the expression when the rewrite/apply/eval step finishes. @@ -148,6 +170,7 @@ class Rule(BaseRule): Note: we want Rules to be serializable so that we can dump and restore Rules in order to make startup time faster. + """ def __init__( @@ -193,6 +216,7 @@ def __repr__(self) -> str: return " %s>" % (self.pattern, self.replace) +# FIXME: the class name would be better called FunctionCallRule. class BuiltinRule(BaseRule): """ A BuiltinRule is a rule that has a replacement term that is associated @@ -249,9 +273,9 @@ def __init__( self.check_options = check_options self.pass_expression = "expression" in function_arguments(function) - # If you update this, you must also update traced_apply_rule + # If you update this, you must also update traced_apply_function # (that's in the same file TraceBuiltins is) - def apply_rule( + def apply_function( self, expression: BaseElement, vars: dict, options: dict, evaluation: Evaluation ): if options and self.check_options: diff --git a/mathics/main.py b/mathics/main.py index 03d4aa2f6..3e6270b4c 100755 --- a/mathics/main.py +++ b/mathics/main.py @@ -19,7 +19,7 @@ import sys from mathics import __version__, license_string, settings, version_string -from mathics.builtin.trace import TraceBuiltins, traced_apply_rule +from mathics.builtin.trace import TraceBuiltins, traced_apply_function from mathics.core.atoms import String from mathics.core.definitions import Definitions, Symbol, autoload_files from mathics.core.evaluation import Evaluation, Output @@ -385,7 +385,7 @@ def main() -> int: extension_modules = default_pymathics_modules if args.trace_builtins: - BuiltinRule.apply_rule = traced_apply_rule + BuiltinRule.apply_rule = traced_apply_function def dump_tracing_stats(): TraceBuiltins.dump_tracing_stats(sort_by="count", evaluation=None)