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Fluent API

fuzzy_infer.fluent

Fluent API for FuzzyInfer - Beautiful, Pythonic inference pipelines.

This module provides a modern, chainable API for fuzzy inference with: - Method chaining for elegant rule and fact composition - Operator overloading for natural syntax - Context managers for sessions - Functional/lambda programming support - Builder patterns for complex rules - Query DSL for powerful pattern matching

Examples:

>>> # Beautiful inference pipeline
>>> with FuzzySession() as session:
...     session.facts(
...         ("is-bird", ["robin"], 0.9),
...         ("is-bird", ["eagle"], 1.0)
...     ).rule(
...         when=("is-bird", "?x"),
...         then=("can-fly", "?x", 0.95)
...     ).infer()
...     flying = session.query("can-fly")
>>> # Functional style
>>> results = (
...     FuzzyInfer()
...     .fact("is-mammal", ["dog"])
...     .fact("is-mammal", ["cat"])
...     .rule(lambda kb: kb["is-mammal"]["?x"] >> kb.add("warm-blooded", "?x"))
...     .run()
...     .where("warm-blooded")
... )

FluentQueryResult

FluentQueryResult(facts: List[Fact], kb: 'FluentKB')

Fluent wrapper for query results with chainable operations.

Source code in fuzzy_infer/fluent.py
def __init__(self, facts: List[Fact], kb: 'FluentKB'):
    self._facts = facts
    self._kb = kb

facts property

facts: List[Fact]

Get raw facts list.

first property

first: Optional[Fact]

Get first fact or None.

degrees property

degrees: List[float]

Get all degrees.

max_degree property

max_degree: Optional[float]

Get maximum degree.

min_degree property

min_degree: Optional[float]

Get minimum degree.

where

where(
    condition: Callable[[Fact], bool],
) -> "FluentQueryResult"

Filter facts by condition.

Source code in fuzzy_infer/fluent.py
def where(self, condition: Callable[[Fact], bool]) -> 'FluentQueryResult':
    """Filter facts by condition."""
    filtered = [f for f in self._facts if condition(f)]
    return FluentQueryResult(filtered, self._kb)

having_degree

having_degree(op: str, value: float) -> 'FluentQueryResult'

Filter by degree comparison.

Source code in fuzzy_infer/fluent.py
def having_degree(self, op: str, value: float) -> 'FluentQueryResult':
    """Filter by degree comparison."""
    ops = {
        '>': lambda d: d > value,
        '>=': lambda d: d >= value,
        '<': lambda d: d < value,
        '<=': lambda d: d <= value,
        '==': lambda d: d == value,
        '!=': lambda d: d != value,
    }
    if op not in ops:
        raise ValueError(f"Invalid operator: {op}")
    return self.where(lambda f: ops[op](f.degree))

with_args

with_args(*args: Any) -> 'FluentQueryResult'

Filter by argument values.

Source code in fuzzy_infer/fluent.py
def with_args(self, *args: Any) -> 'FluentQueryResult':
    """Filter by argument values."""
    return self.where(lambda f: f.args == list(args))

map

map(func: Callable[[Fact], Any]) -> List[Any]

Map function over facts.

Source code in fuzzy_infer/fluent.py
def map(self, func: Callable[[Fact], Any]) -> List[Any]:
    """Map function over facts."""
    return [func(f) for f in self._facts]

to_dict

to_dict() -> List[Dict[str, Any]]

Convert to list of dicts.

Source code in fuzzy_infer/fluent.py
def to_dict(self) -> List[Dict[str, Any]]:
    """Convert to list of dicts."""
    return [f.to_dict() for f in self._facts]

to_json

to_json() -> str

Convert to JSON string.

Source code in fuzzy_infer/fluent.py
def to_json(self) -> str:
    """Convert to JSON string."""
    return json.dumps(self.to_dict(), indent=2)

PatternMatcher

PatternMatcher(
    predicate: str, kb: Optional["FluentKB"] = None
)

DSL for pattern matching in queries and rules.

Source code in fuzzy_infer/fluent.py
def __init__(self, predicate: str, kb: Optional['FluentKB'] = None):
    self.predicate = predicate
    self.args: List[Any] = []
    self.constraints: List[Callable] = []
    self.kb = kb

to_condition

to_condition() -> Condition

Convert to Condition object.

Source code in fuzzy_infer/fluent.py
def to_condition(self) -> Condition:
    """Convert to Condition object."""
    cond = Condition(self.predicate, self.args)
    # Add degree constraints
    for constraint in self.constraints:
        # This is simplified - would need proper Condition support
        pass
    return cond

FluentRule

FluentRule(
    condition: Union[PatternMatcher, Tuple, List],
    action: Union[PatternMatcher, Tuple, Callable],
    kb: Optional["FluentKB"] = None,
)

Fluent rule representation.

Source code in fuzzy_infer/fluent.py
def __init__(
    self,
    condition: Union[PatternMatcher, Tuple, List],
    action: Union[PatternMatcher, Tuple, Callable],
    kb: Optional['FluentKB'] = None
):
    self.conditions = [condition] if not isinstance(condition, list) else condition
    self.actions = [action] if not isinstance(action, list) else action
    self.kb = kb
    self.name: Optional[str] = None
    self.priority: int = 50

named

named(name: str) -> 'FluentRule'

Set rule name.

Source code in fuzzy_infer/fluent.py
def named(self, name: str) -> 'FluentRule':
    """Set rule name."""
    self.name = name
    return self

with_priority

with_priority(priority: int) -> 'FluentRule'

Set rule priority.

Source code in fuzzy_infer/fluent.py
def with_priority(self, priority: int) -> 'FluentRule':
    """Set rule priority."""
    self.priority = priority
    return self

build

build() -> Rule

Build Rule object.

Source code in fuzzy_infer/fluent.py
def build(self) -> Rule:
    """Build Rule object."""
    # Convert conditions and actions to proper format
    conditions = []
    actions = []

    for cond in self.conditions:
        if isinstance(cond, PatternMatcher):
            conditions.append(cond.to_condition())
        elif isinstance(cond, tuple):
            pred, *args = cond
            conditions.append(Condition(pred, args))
        else:
            conditions.append(cond)

    for action in self.actions:
        if isinstance(action, PatternMatcher):
            actions.append(Action(
                action_type="add",
                fact={
                    "pred": action.predicate,
                    "args": action.args,
                    "deg": 1.0
                }
            ))
        elif isinstance(action, tuple):
            if len(action) == 2:
                pred, args = action
                degree = 1.0
            else:
                pred, args, degree = action
            if not isinstance(args, list):
                args = [args]
            actions.append(Action(
                action_type="add",
                fact={
                    "pred": pred,
                    "args": args,
                    "deg": degree
                }
            ))
        elif callable(action):
            # Lambda action - need special handling
            pass
        else:
            actions.append(action)

    return Rule(
        name=self.name,
        conditions=conditions,
        actions=actions,
        priority=self.priority
    )

FluentKB

FluentKB(engine: Optional[FuzzyInfer] = None)

Fluent knowledge base interface.

Source code in fuzzy_infer/fluent.py
def __init__(self, engine: Optional[FuzzyInfer] = None):
    self._engine = engine or FuzzyInfer()
    self._patterns: Dict[str, PatternMatcher] = {}

engine property

engine: FuzzyInfer

Get underlying engine.

fact

fact(
    predicate: str,
    args: Union[List[Any], Any],
    degree: float = 1.0,
) -> "FluentKB"

Add a single fact.

Source code in fuzzy_infer/fluent.py
def fact(self, predicate: str, args: Union[List[Any], Any], degree: float = 1.0) -> 'FluentKB':
    """Add a single fact."""
    if not isinstance(args, list):
        args = [args]
    self._engine.add_fact(Fact(predicate, args, degree))
    return self

facts

facts(
    *facts: Union[FactTuple, SimpleFact, Tuple]
) -> "FluentKB"

Add multiple facts.

Source code in fuzzy_infer/fluent.py
def facts(self, *facts: Union[FactTuple, SimpleFact, Tuple]) -> 'FluentKB':
    """Add multiple facts."""
    for f in facts:
        if len(f) == 2:
            pred, args = f
            degree = 1.0
        elif len(f) == 3:
            # Could be (pred, args, degree) or (pred, arg1, arg2) for multi-arg facts
            if isinstance(f[2], (int, float)) and 0 <= f[2] <= 1:
                # It's a degree
                pred, args, degree = f
            else:
                # It's a multi-arg fact like ("species", ["rex"], "dog")
                pred = f[0]
                args = list(f[1:])
                degree = 1.0
        elif len(f) == 4:
            # Multi-arg fact with degree like ("species", ["rex"], "dog", 1.0)
            pred = f[0]
            args = list(f[1:-1])
            degree = f[-1]
        else:
            pred, args, degree = f[0], list(f[1:]), 1.0
        self.fact(pred, args, degree)
    return self

rule

rule(
    when: Optional[
        Union[PatternMatcher, Tuple, Callable, List]
    ] = None,
    then: Optional[
        Union[PatternMatcher, Tuple, Callable, List]
    ] = None,
    **kwargs
) -> "FluentKB"

Add a rule using keyword arguments or builder.

Source code in fuzzy_infer/fluent.py
def rule(
    self,
    when: Optional[Union[PatternMatcher, Tuple, Callable, List]] = None,
    then: Optional[Union[PatternMatcher, Tuple, Callable, List]] = None,
    **kwargs
) -> 'FluentKB':
    """Add a rule using keyword arguments or builder."""
    if when is not None and then is not None:
        # Handle list of conditions
        if isinstance(when, list):
            conditions = when
        else:
            conditions = [when]

        # Handle list of actions
        if isinstance(then, list):
            actions = then
        else:
            actions = [then]

        # Simple rule creation
        rule = FluentRule(conditions, actions, self)
        if 'name' in kwargs:
            rule.named(kwargs['name'])
        if 'priority' in kwargs:
            rule.with_priority(kwargs['priority'])
        self._engine.add_rule(rule.build())
    elif callable(when):
        # Lambda-style rule - skip for now since it needs special handling
        pass
    elif isinstance(when, dict):
        # Direct dict rule
        self._engine.add_rule(when)
    return self

rules

rules(*rules: Union[Rule, FluentRule, Dict]) -> 'FluentKB'

Add multiple rules.

Source code in fuzzy_infer/fluent.py
def rules(self, *rules: Union[Rule, FluentRule, Dict]) -> 'FluentKB':
    """Add multiple rules."""
    for r in rules:
        if isinstance(r, FluentRule):
            self._engine.add_rule(r.build())
        elif isinstance(r, Rule):
            self._engine.add_rule(r)
        elif isinstance(r, dict):
            self._engine.add_rule(r)
    return self

infer

infer(max_iterations: int = 100) -> 'FluentKB'

Run inference.

Source code in fuzzy_infer/fluent.py
def infer(self, max_iterations: int = 100) -> 'FluentKB':
    """Run inference."""
    self._engine.run(max_iterations)
    return self

run

run(max_iterations: int = 100) -> 'FluentKB'

Alias for infer.

Source code in fuzzy_infer/fluent.py
def run(self, max_iterations: int = 100) -> 'FluentKB':
    """Alias for infer."""
    return self.infer(max_iterations)

query

query(
    predicate: str,
    args: Optional[Union[List[Any], Any]] = None,
) -> FluentQueryResult

Query facts.

Source code in fuzzy_infer/fluent.py
def query(
    self,
    predicate: str,
    args: Optional[Union[List[Any], Any]] = None
) -> FluentQueryResult:
    """Query facts."""
    if args is not None:
        if not isinstance(args, list):
            args = [args]
        facts = self._engine.query(predicate, args)
    else:
        facts = self._engine.query(predicate)
    return FluentQueryResult(facts, self)

where

where(predicate: str) -> FluentQueryResult

Query all facts with predicate.

Source code in fuzzy_infer/fluent.py
def where(self, predicate: str) -> FluentQueryResult:
    """Query all facts with predicate."""
    facts = self._engine.query(predicate)
    return FluentQueryResult(facts, self)

all_facts

all_facts() -> List[Fact]

Get all facts.

Source code in fuzzy_infer/fluent.py
def all_facts(self) -> List[Fact]:
    """Get all facts."""
    return list(self._engine.facts.values())

clear_facts

clear_facts() -> 'FluentKB'

Clear all facts.

Source code in fuzzy_infer/fluent.py
def clear_facts(self) -> 'FluentKB':
    """Clear all facts."""
    self._engine.facts.clear()
    return self

clear_rules

clear_rules() -> 'FluentKB'

Clear all rules.

Source code in fuzzy_infer/fluent.py
def clear_rules(self) -> 'FluentKB':
    """Clear all rules."""
    self._engine.rules.clear()
    return self

clear

clear() -> 'FluentKB'

Clear everything.

Source code in fuzzy_infer/fluent.py
def clear(self) -> 'FluentKB':
    """Clear everything."""
    return self.clear_facts().clear_rules()

save

save(path: Union[str, Path]) -> 'FluentKB'

Save to file.

Source code in fuzzy_infer/fluent.py
def save(self, path: Union[str, Path]) -> 'FluentKB':
    """Save to file."""
    from fuzzy_infer.jsonl import KnowledgeBaseIO
    KnowledgeBaseIO.save(self._engine, path)
    return self

load

load(path: Union[str, Path]) -> 'FluentKB'

Load from file.

Source code in fuzzy_infer/fluent.py
def load(self, path: Union[str, Path]) -> 'FluentKB':
    """Load from file."""
    from fuzzy_infer.jsonl import KnowledgeBaseIO
    loaded = KnowledgeBaseIO.load(path)
    self._engine = loaded
    return self

FuzzySession

FuzzySession(max_iterations: int = 100)

Context manager for inference sessions.

Source code in fuzzy_infer/fluent.py
def __init__(self, max_iterations: int = 100):
    self.max_iterations = max_iterations
    self.kb: Optional[FluentKB] = None

Pipeline

Pipeline()

Inference pipeline builder for complex workflows.

Source code in fuzzy_infer/fluent.py
def __init__(self):
    self.steps: List[Callable] = []
    self.kb = FluentKB()

step

step(func: Callable) -> 'Pipeline'

Add a step to the pipeline.

Source code in fuzzy_infer/fluent.py
def step(self, func: Callable) -> 'Pipeline':
    """Add a step to the pipeline."""
    self.steps.append(func)
    return self

facts_from

facts_from(
    source: Union[str, Path, Iterator],
) -> "Pipeline"

Load facts from source.

Source code in fuzzy_infer/fluent.py
def facts_from(self, source: Union[str, Path, Iterator]) -> 'Pipeline':
    """Load facts from source."""
    def load_facts(kb: FluentKB):
        if isinstance(source, (str, Path)):
            kb.load(source)
        else:
            for fact in source:
                if isinstance(fact, Fact):
                    kb._engine.add_fact(fact)
                elif isinstance(fact, tuple):
                    kb.fact(*fact)
    self.steps.append(load_facts)
    return self

rules_from

rules_from(source: Union[str, Path, List]) -> 'Pipeline'

Load rules from source.

Source code in fuzzy_infer/fluent.py
def rules_from(self, source: Union[str, Path, List]) -> 'Pipeline':
    """Load rules from source."""
    def load_rules(kb: FluentKB):
        if isinstance(source, (str, Path)):
            # Load from file
            pass
        else:
            kb.rules(*source)
    self.steps.append(load_rules)
    return self

transform

transform(func: Callable[[FluentKB], None]) -> 'Pipeline'

Apply transformation to KB.

Source code in fuzzy_infer/fluent.py
def transform(self, func: Callable[[FluentKB], None]) -> 'Pipeline':
    """Apply transformation to KB."""
    self.steps.append(func)
    return self

infer

infer(max_iterations: int = 100) -> 'Pipeline'

Add inference step.

Source code in fuzzy_infer/fluent.py
def infer(self, max_iterations: int = 100) -> 'Pipeline':
    """Add inference step."""
    self.steps.append(lambda kb: kb.infer(max_iterations))
    return self

filter_facts

filter_facts(
    predicate: Callable[[Fact], bool],
) -> "Pipeline"

Filter facts.

Source code in fuzzy_infer/fluent.py
def filter_facts(self, predicate: Callable[[Fact], bool]) -> 'Pipeline':
    """Filter facts."""
    def filter_step(kb: FluentKB):
        filtered = {k: v for k, v in kb._engine.facts.items()
                   if predicate(v)}
        kb._engine.facts = filtered
    self.steps.append(filter_step)
    return self

run

run() -> FluentKB

Execute pipeline.

Source code in fuzzy_infer/fluent.py
def run(self) -> FluentKB:
    """Execute pipeline."""
    for step in self.steps:
        step(self.kb)
    return self.kb

stream

stream(input_stream: Iterator[Fact]) -> Iterator[Fact]

Stream processing mode.

Source code in fuzzy_infer/fluent.py
def stream(self, input_stream: Iterator[Fact]) -> Iterator[Fact]:
    """Stream processing mode."""
    for fact in input_stream:
        self.kb._engine.add_fact(fact)
        # Run inference after each fact
        self.kb.infer(1)
        # Yield new facts
        for f in self.kb._engine.facts.values():
            yield f

FuzzyExpr

FuzzyExpr(expr)

Expression builder for complex conditions.

Source code in fuzzy_infer/fluent.py
def __init__(self, expr):
    self.expr = expr

fuzzy

fuzzy(*facts: Union[FactTuple, SimpleFact]) -> FluentKB

Quick fuzzy KB creation.

Source code in fuzzy_infer/fluent.py
def fuzzy(*facts: Union[FactTuple, SimpleFact]) -> FluentKB:
    """Quick fuzzy KB creation."""
    kb = FluentKB()
    return kb.facts(*facts)

when

when(predicate: str, *args: Any) -> PatternMatcher

Create pattern matcher for conditions.

Source code in fuzzy_infer/fluent.py
def when(predicate: str, *args: Any) -> PatternMatcher:
    """Create pattern matcher for conditions."""
    pattern = PatternMatcher(predicate)
    if args:
        pattern.args = list(args)
    return pattern

then

then(
    predicate: str, *args: Any, degree: float = 1.0
) -> Tuple

Create action tuple.

Source code in fuzzy_infer/fluent.py
def then(predicate: str, *args: Any, degree: float = 1.0) -> Tuple:
    """Create action tuple."""
    # If degree is passed as last positional argument
    if args and isinstance(args[-1], (int, float)) and 0 <= args[-1] <= 1:
        actual_args = list(args[:-1])
        actual_degree = args[-1]
        return (predicate, actual_args, actual_degree)
    return (predicate, list(args), degree)

stream_session

stream_session(
    input_file: Optional[Path] = None,
    output_file: Optional[Path] = None,
)

Context manager for stream processing.

Source code in fuzzy_infer/fluent.py
@contextmanager
def stream_session(input_file: Optional[Path] = None, output_file: Optional[Path] = None):
    """Context manager for stream processing."""
    import sys

    old_stdin = sys.stdin
    old_stdout = sys.stdout

    try:
        if input_file:
            sys.stdin = open(input_file, 'r')
        if output_file:
            sys.stdout = open(output_file, 'w')

        kb = FluentKB()
        yield kb

    finally:
        if input_file and sys.stdin != old_stdin:
            sys.stdin.close()
            sys.stdin = old_stdin
        if output_file and sys.stdout != old_stdout:
            sys.stdout.close()
            sys.stdout = old_stdout

Overview

The fuzzy_infer.fluent module provides a modern, Pythonic interface for fuzzy inference with method chaining, operator overloading, and functional programming patterns.

Quick Reference

from fuzzy_infer.fluent import FluentKB, FuzzySession, fuzzy, when, then

# Beautiful chaining
results = (
    FluentKB()
    .fact("is-bird", ["robin"], 0.9)
    .rule(when=("is-bird", "?x"), then=("can-fly", "?x", 0.85))
    .infer()
    .where("can-fly")
)

# Context manager
with FuzzySession() as session:
    session.facts(("is-bird", ["robin"], 0.9))
    session.rule(when=("is-bird", "?x"), then=("can-fly", "?x"))
    results = session.query("can-fly")

# Quick creation
kb = fuzzy(
    ("is-bird", ["robin"], 0.9),
    ("is-bird", ["eagle"], 1.0)
)

Core Classes

FluentKB

Fluent knowledge base interface.

Source code in fuzzy_infer/fluent.py
def __init__(self, engine: Optional[FuzzyInfer] = None):
    self._engine = engine or FuzzyInfer()
    self._patterns: Dict[str, PatternMatcher] = {}

fact

fact(
    predicate: str,
    args: Union[List[Any], Any],
    degree: float = 1.0,
) -> "FluentKB"

Add a single fact.

Source code in fuzzy_infer/fluent.py
def fact(self, predicate: str, args: Union[List[Any], Any], degree: float = 1.0) -> 'FluentKB':
    """Add a single fact."""
    if not isinstance(args, list):
        args = [args]
    self._engine.add_fact(Fact(predicate, args, degree))
    return self

facts

facts(
    *facts: Union[FactTuple, SimpleFact, Tuple]
) -> "FluentKB"

Add multiple facts.

Source code in fuzzy_infer/fluent.py
def facts(self, *facts: Union[FactTuple, SimpleFact, Tuple]) -> 'FluentKB':
    """Add multiple facts."""
    for f in facts:
        if len(f) == 2:
            pred, args = f
            degree = 1.0
        elif len(f) == 3:
            # Could be (pred, args, degree) or (pred, arg1, arg2) for multi-arg facts
            if isinstance(f[2], (int, float)) and 0 <= f[2] <= 1:
                # It's a degree
                pred, args, degree = f
            else:
                # It's a multi-arg fact like ("species", ["rex"], "dog")
                pred = f[0]
                args = list(f[1:])
                degree = 1.0
        elif len(f) == 4:
            # Multi-arg fact with degree like ("species", ["rex"], "dog", 1.0)
            pred = f[0]
            args = list(f[1:-1])
            degree = f[-1]
        else:
            pred, args, degree = f[0], list(f[1:]), 1.0
        self.fact(pred, args, degree)
    return self

rule

rule(
    when: Optional[
        Union[PatternMatcher, Tuple, Callable, List]
    ] = None,
    then: Optional[
        Union[PatternMatcher, Tuple, Callable, List]
    ] = None,
    **kwargs
) -> "FluentKB"

Add a rule using keyword arguments or builder.

Source code in fuzzy_infer/fluent.py
def rule(
    self,
    when: Optional[Union[PatternMatcher, Tuple, Callable, List]] = None,
    then: Optional[Union[PatternMatcher, Tuple, Callable, List]] = None,
    **kwargs
) -> 'FluentKB':
    """Add a rule using keyword arguments or builder."""
    if when is not None and then is not None:
        # Handle list of conditions
        if isinstance(when, list):
            conditions = when
        else:
            conditions = [when]

        # Handle list of actions
        if isinstance(then, list):
            actions = then
        else:
            actions = [then]

        # Simple rule creation
        rule = FluentRule(conditions, actions, self)
        if 'name' in kwargs:
            rule.named(kwargs['name'])
        if 'priority' in kwargs:
            rule.with_priority(kwargs['priority'])
        self._engine.add_rule(rule.build())
    elif callable(when):
        # Lambda-style rule - skip for now since it needs special handling
        pass
    elif isinstance(when, dict):
        # Direct dict rule
        self._engine.add_rule(when)
    return self

rules

rules(*rules: Union[Rule, FluentRule, Dict]) -> 'FluentKB'

Add multiple rules.

Source code in fuzzy_infer/fluent.py
def rules(self, *rules: Union[Rule, FluentRule, Dict]) -> 'FluentKB':
    """Add multiple rules."""
    for r in rules:
        if isinstance(r, FluentRule):
            self._engine.add_rule(r.build())
        elif isinstance(r, Rule):
            self._engine.add_rule(r)
        elif isinstance(r, dict):
            self._engine.add_rule(r)
    return self

infer

infer(max_iterations: int = 100) -> 'FluentKB'

Run inference.

Source code in fuzzy_infer/fluent.py
def infer(self, max_iterations: int = 100) -> 'FluentKB':
    """Run inference."""
    self._engine.run(max_iterations)
    return self

query

query(
    predicate: str,
    args: Optional[Union[List[Any], Any]] = None,
) -> FluentQueryResult

Query facts.

Source code in fuzzy_infer/fluent.py
def query(
    self,
    predicate: str,
    args: Optional[Union[List[Any], Any]] = None
) -> FluentQueryResult:
    """Query facts."""
    if args is not None:
        if not isinstance(args, list):
            args = [args]
        facts = self._engine.query(predicate, args)
    else:
        facts = self._engine.query(predicate)
    return FluentQueryResult(facts, self)

where

where(predicate: str) -> FluentQueryResult

Query all facts with predicate.

Source code in fuzzy_infer/fluent.py
def where(self, predicate: str) -> FluentQueryResult:
    """Query all facts with predicate."""
    facts = self._engine.query(predicate)
    return FluentQueryResult(facts, self)

clear

clear() -> 'FluentKB'

Clear everything.

Source code in fuzzy_infer/fluent.py
def clear(self) -> 'FluentKB':
    """Clear everything."""
    return self.clear_facts().clear_rules()

save

save(path: Union[str, Path]) -> 'FluentKB'

Save to file.

Source code in fuzzy_infer/fluent.py
def save(self, path: Union[str, Path]) -> 'FluentKB':
    """Save to file."""
    from fuzzy_infer.jsonl import KnowledgeBaseIO
    KnowledgeBaseIO.save(self._engine, path)
    return self

load

load(path: Union[str, Path]) -> 'FluentKB'

Load from file.

Source code in fuzzy_infer/fluent.py
def load(self, path: Union[str, Path]) -> 'FluentKB':
    """Load from file."""
    from fuzzy_infer.jsonl import KnowledgeBaseIO
    loaded = KnowledgeBaseIO.load(path)
    self._engine = loaded
    return self

Examples

from fuzzy_infer.fluent import FluentKB

# Method chaining
kb = (
    FluentKB()
    .fact("is-mammal", ["dog"])
    .fact("is-mammal", ["cat"])
    .rule(
        when=("is-mammal", "?x"),
        then=("warm-blooded", "?x", 0.99)
    )
    .infer()
)

# Query results
warm_blooded = kb.where("warm-blooded")
for fact in warm_blooded:
    print(f"{fact.args[0]} is warm-blooded ({fact.degree:.0%})")

# Pattern matching with subscript
kb = FluentKB()
kb.fact("temperature", ["room-1"], 0.8)
temp_pattern = kb["temperature"]["?room"] >= 0.7
kb.rule(when=temp_pattern, then=("ac-on", "?room", 0.95))

# Save/load
kb.save("knowledge.jsonl")
loaded_kb = FluentKB().load("knowledge.jsonl")

FuzzySession

Context manager for inference sessions.

Source code in fuzzy_infer/fluent.py
def __init__(self, max_iterations: int = 100):
    self.max_iterations = max_iterations
    self.kb: Optional[FluentKB] = None

__enter__

__enter__() -> FluentKB

Enter session.

Source code in fuzzy_infer/fluent.py
def __enter__(self) -> FluentKB:
    """Enter session."""
    self.kb = FluentKB()
    return self.kb

__exit__

__exit__(exc_type, exc_val, exc_tb)

Exit session - auto-run inference if not already done.

Source code in fuzzy_infer/fluent.py
def __exit__(self, exc_type, exc_val, exc_tb):
    """Exit session - auto-run inference if not already done."""
    if self.kb and not exc_type:
        # Check if inference was already run
        if not self.kb._engine.inference_log:
            self.kb.infer(self.max_iterations)

Examples

from fuzzy_infer.fluent import FuzzySession

# Auto-inference on context exit
with FuzzySession() as session:
    session.facts(
        ("is-bird", ["robin"], 0.9),
        ("is-bird", ["eagle"], 1.0)
    )
    session.rule(
        when=("is-bird", "?x"),
        then=("can-fly", "?x", 0.95)
    )
    # Inference runs automatically here
    flying = session.query("can-fly")

# Manual inference control
with FuzzySession(auto_infer=False) as session:
    session.fact("is-bird", ["robin"], 0.9)
    session.infer()  # Explicit
    results = session.query("can-fly")

FluentQueryResult

Fluent wrapper for query results with chainable operations.

Source code in fuzzy_infer/fluent.py
def __init__(self, facts: List[Fact], kb: 'FluentKB'):
    self._facts = facts
    self._kb = kb

first property

first: Optional[Fact]

Get first fact or None.

degrees property

degrees: List[float]

Get all degrees.

max_degree property

max_degree: Optional[float]

Get maximum degree.

min_degree property

min_degree: Optional[float]

Get minimum degree.

where

where(
    condition: Callable[[Fact], bool],
) -> "FluentQueryResult"

Filter facts by condition.

Source code in fuzzy_infer/fluent.py
def where(self, condition: Callable[[Fact], bool]) -> 'FluentQueryResult':
    """Filter facts by condition."""
    filtered = [f for f in self._facts if condition(f)]
    return FluentQueryResult(filtered, self._kb)

having_degree

having_degree(op: str, value: float) -> 'FluentQueryResult'

Filter by degree comparison.

Source code in fuzzy_infer/fluent.py
def having_degree(self, op: str, value: float) -> 'FluentQueryResult':
    """Filter by degree comparison."""
    ops = {
        '>': lambda d: d > value,
        '>=': lambda d: d >= value,
        '<': lambda d: d < value,
        '<=': lambda d: d <= value,
        '==': lambda d: d == value,
        '!=': lambda d: d != value,
    }
    if op not in ops:
        raise ValueError(f"Invalid operator: {op}")
    return self.where(lambda f: ops[op](f.degree))

with_args

with_args(*args: Any) -> 'FluentQueryResult'

Filter by argument values.

Source code in fuzzy_infer/fluent.py
def with_args(self, *args: Any) -> 'FluentQueryResult':
    """Filter by argument values."""
    return self.where(lambda f: f.args == list(args))

map

map(func: Callable[[Fact], Any]) -> List[Any]

Map function over facts.

Source code in fuzzy_infer/fluent.py
def map(self, func: Callable[[Fact], Any]) -> List[Any]:
    """Map function over facts."""
    return [func(f) for f in self._facts]

to_dict

to_dict() -> List[Dict[str, Any]]

Convert to list of dicts.

Source code in fuzzy_infer/fluent.py
def to_dict(self) -> List[Dict[str, Any]]:
    """Convert to list of dicts."""
    return [f.to_dict() for f in self._facts]

to_json

to_json() -> str

Convert to JSON string.

Source code in fuzzy_infer/fluent.py
def to_json(self) -> str:
    """Convert to JSON string."""
    return json.dumps(self.to_dict(), indent=2)

Examples

# Query with chaining
results = (
    kb.where("species")
    .with_args("dog")
    .having_degree('>', 0.8)
)

# Functional operations
names = kb.where("person").map(lambda f: f.args[0])

# Degree filtering
high_conf = kb.query("is-mammal").having_degree('>=', 0.9)

# Get first result
first = kb.query("can-fly", ["tweety"]).first
if first:
    print(f"Confidence: {first.degree}")

# Get statistics
results = kb.where("temperature")
print(f"Max degree: {results.max_degree}")
print(f"Min degree: {results.min_degree}")
print(f"All degrees: {results.degrees}")

# Convert to JSON
json_str = results.to_json()
dict_list = results.to_dict()

Pipeline

Inference pipeline builder for complex workflows.

Source code in fuzzy_infer/fluent.py
def __init__(self):
    self.steps: List[Callable] = []
    self.kb = FluentKB()

facts_from

facts_from(
    source: Union[str, Path, Iterator],
) -> "Pipeline"

Load facts from source.

Source code in fuzzy_infer/fluent.py
def facts_from(self, source: Union[str, Path, Iterator]) -> 'Pipeline':
    """Load facts from source."""
    def load_facts(kb: FluentKB):
        if isinstance(source, (str, Path)):
            kb.load(source)
        else:
            for fact in source:
                if isinstance(fact, Fact):
                    kb._engine.add_fact(fact)
                elif isinstance(fact, tuple):
                    kb.fact(*fact)
    self.steps.append(load_facts)
    return self

rules_from

rules_from(source: Union[str, Path, List]) -> 'Pipeline'

Load rules from source.

Source code in fuzzy_infer/fluent.py
def rules_from(self, source: Union[str, Path, List]) -> 'Pipeline':
    """Load rules from source."""
    def load_rules(kb: FluentKB):
        if isinstance(source, (str, Path)):
            # Load from file
            pass
        else:
            kb.rules(*source)
    self.steps.append(load_rules)
    return self

transform

transform(func: Callable[[FluentKB], None]) -> 'Pipeline'

Apply transformation to KB.

Source code in fuzzy_infer/fluent.py
def transform(self, func: Callable[[FluentKB], None]) -> 'Pipeline':
    """Apply transformation to KB."""
    self.steps.append(func)
    return self

filter_facts

filter_facts(
    predicate: Callable[[Fact], bool],
) -> "Pipeline"

Filter facts.

Source code in fuzzy_infer/fluent.py
def filter_facts(self, predicate: Callable[[Fact], bool]) -> 'Pipeline':
    """Filter facts."""
    def filter_step(kb: FluentKB):
        filtered = {k: v for k, v in kb._engine.facts.items()
                   if predicate(v)}
        kb._engine.facts = filtered
    self.steps.append(filter_step)
    return self

infer

infer(max_iterations: int = 100) -> 'Pipeline'

Add inference step.

Source code in fuzzy_infer/fluent.py
def infer(self, max_iterations: int = 100) -> 'Pipeline':
    """Add inference step."""
    self.steps.append(lambda kb: kb.infer(max_iterations))
    return self

run

run() -> FluentKB

Execute pipeline.

Source code in fuzzy_infer/fluent.py
def run(self) -> FluentKB:
    """Execute pipeline."""
    for step in self.steps:
        step(self.kb)
    return self.kb

Examples

from fuzzy_infer.fluent import Pipeline

# Complex workflow
pipeline = (
    Pipeline()
    .facts_from("sensors.jsonl")
    .rules_from("rules.jsonl")
    .transform(lambda kb: kb.fact("extra", ["data"], 0.5))
    .filter_facts(lambda f: f.degree > 0.6)
    .infer()
)

result_kb = pipeline.run()

# Multi-stage processing
pipeline = (
    Pipeline()
    .facts_from([
        ("temperature", ["room-1"], 0.8),
        ("humidity", ["room-1"], 0.6)
    ])
    .transform(lambda kb: kb.rule(
        when=("temperature", "?r"),
        then=("hot", "?r", 0.9)
    ))
    .infer()
)

Helper Functions

fuzzy()

Quick fuzzy KB creation.

Source code in fuzzy_infer/fluent.py
def fuzzy(*facts: Union[FactTuple, SimpleFact]) -> FluentKB:
    """Quick fuzzy KB creation."""
    kb = FluentKB()
    return kb.facts(*facts)
from fuzzy_infer.fluent import fuzzy

# Quick KB creation
kb = fuzzy(
    ("is-cat", ["fluffy"], 1.0),
    ("has-fur", ["fluffy"], 0.95),
    ("likes-fish", ["fluffy"], 0.8)
)

# Returns FluentKB ready for chaining
results = fuzzy(
    ("is-bird", ["robin"], 0.9)
).rule(
    when=("is-bird", "?x"),
    then=("can-fly", "?x", 0.85)
).infer().where("can-fly")

when() and then()

Create pattern matcher for conditions.

Source code in fuzzy_infer/fluent.py
def when(predicate: str, *args: Any) -> PatternMatcher:
    """Create pattern matcher for conditions."""
    pattern = PatternMatcher(predicate)
    if args:
        pattern.args = list(args)
    return pattern

Create action tuple.

Source code in fuzzy_infer/fluent.py
def then(predicate: str, *args: Any, degree: float = 1.0) -> Tuple:
    """Create action tuple."""
    # If degree is passed as last positional argument
    if args and isinstance(args[-1], (int, float)) and 0 <= args[-1] <= 1:
        actual_args = list(args[:-1])
        actual_degree = args[-1]
        return (predicate, actual_args, actual_degree)
    return (predicate, list(args), degree)
from fuzzy_infer.fluent import when, then

# Create pattern helpers
condition = when("is-mammal", "?x")
action = then("warm-blooded", "?x", 0.99)

kb.rule(when=condition, then=action)

# Multiple conditions
kb.rule(
    when=[
        when("is-bird", "?x"),
        when("has-wings", "?x")
    ],
    then=then("can-fly", "?x", 0.9)
)

stream_session()

Context manager for stream processing.

Source code in fuzzy_infer/fluent.py
@contextmanager
def stream_session(input_file: Optional[Path] = None, output_file: Optional[Path] = None):
    """Context manager for stream processing."""
    import sys

    old_stdin = sys.stdin
    old_stdout = sys.stdout

    try:
        if input_file:
            sys.stdin = open(input_file, 'r')
        if output_file:
            sys.stdout = open(output_file, 'w')

        kb = FluentKB()
        yield kb

    finally:
        if input_file and sys.stdin != old_stdin:
            sys.stdin.close()
            sys.stdin = old_stdin
        if output_file and sys.stdout != old_stdout:
            sys.stdout.close()
            sys.stdout = old_stdout
from fuzzy_infer.fluent import stream_session

# Streaming inference
def sensor_stream():
    import random
    while True:
        yield ("sensor", [f"s{random.randint(1,10)}"], random.random())

with stream_session() as kb:
    for fact in sensor_stream():
        kb.fact(*fact)
        if fact[2] > 0.9:
            kb.fact("alert", fact[1], 0.95)
        kb.infer(max_iterations=1)
        alerts = kb.where("alert")
        if alerts:
            print(f"Alert: {alerts.first}")

Operator Overloading

Subscript Access

# Pattern creation
kb = FluentKB()
pattern = kb["temperature"]["?room"]  # Matches temperature(?room)

# With arguments
pattern = kb["has-skill"]["?person", "python"]

# Attribute access (underscores → hyphens)
pattern = kb.is_mammal["?x"]  # Matches is-mammal(?x)

Comparison Operators

# Degree constraints
high_temp = kb["temperature"]["?x"] > 0.8
low_temp = kb["temperature"]["?x"] <= 0.3
exact = kb["confidence"]["?x"] == 0.95

# Use in rules
kb.rule(when=high_temp, then=("ac-on", "?x", 0.95))

Rule Creation with >>

# Natural rule syntax
rule = kb["is-bird"]["?x"] >> ("can-fly", "?x", 0.9)

# Equivalent to:
kb.rule(
    when=("is-bird", "?x"),
    then=("can-fly", "?x", 0.9)
)

Logical Operators

# AND conditions
cold = kb["temperature"]["?x"] < 0.3
dry = kb["humidity"]["?x"] < 0.4
desert = cold & dry

# NOT operation
not_hot = ~kb["temperature"]["?x"]

Complete Examples

Animal Classification

from fuzzy_infer.fluent import FluentKB

kb = (
    FluentKB()
    .facts(
        ("has-fur", ["rex"], 1.0),
        ("barks", ["rex"], 0.95),
        ("has-wings", ["tweety"], 1.0),
        ("tweets", ["tweety"], 0.9)
    )
    .rule(
        when=[("has-fur", "?x"), ("barks", "?x")],
        then=("is-dog", "?x", 0.95)
    )
    .rule(
        when=[("has-wings", "?x"), ("tweets", "?x")],
        then=("is-bird", "?x", 0.9)
    )
    .infer()
)

# Check classifications
for animal in ["rex", "tweety"]:
    dog = kb.query("is-dog", [animal]).first
    bird = kb.query("is-bird", [animal]).first

    if dog:
        print(f"{animal} is a dog ({dog.degree:.0%})")
    elif bird:
        print(f"{animal} is a bird ({bird.degree:.0%})")

IoT Sensor Management

from fuzzy_infer.fluent import FuzzySession

with FuzzySession() as kb:
    kb.facts(
        ("sensor", ["temp-1"], 0.75),
        ("sensor", ["humidity-1"], 0.60),
        ("sensor", ["pressure-1"], 0.45)
    )

    kb.rule(
        when=kb["sensor"]["?s"] > 0.7,
        then=("alert", "?s", 0.9),
        name="high-reading-alert"
    ).rule(
        when=kb["sensor"]["?s"] < 0.3,
        then=("maintenance", "?s", 0.8),
        name="low-reading-check"
    )

    alerts = kb.infer().where("alert")
    for alert in alerts:
        print(f"Alert: {alert.args[0]} at {alert.degree:.0%}")

Functional Style

from fuzzy_infer.fluent import fuzzy

kb = fuzzy(
    ("age", ["alice"], 0.3),    # Young
    ("age", ["bob"], 0.7),      # Middle-aged
    ("age", ["charlie"], 0.95)  # Elderly
)

kb.rule(
    when=("age", "?person"),
    then=lambda facts: [
        ("life-stage", facts["?person"], "young", 1.0 - facts.degree),
        ("life-stage", facts["?person"], "old", facts.degree)
    ]
)

kb.infer()

young_people = (
    kb.query("life-stage")
    .where(lambda f: f.args[1] == "young" and f.degree > 0.5)
    .map(lambda f: f.args[0])
)

print(f"Young people: {young_people}")

Best Practices

1. Use Context Managers

# Good - automatic cleanup
with FuzzySession() as kb:
    kb.facts(data)
    results = kb.query("target")

# Avoid - manual management
kb = FluentKB()
kb.facts(data)
# ... might forget to clean up

2. Chain Methods for Readability

# Good - clear flow
results = (
    kb.facts(data)
    .rules(rules)
    .infer()
    .where("target")
)

# Avoid - harder to follow
kb.facts(data)
kb.rules(rules)
kb.infer()
results = kb.where("target")

3. Use Helper Functions

# Good - clear intent
kb.rule(
    when=when("is-bird", "?x"),
    then=then("can-fly", "?x", 0.9)
)

# Also good but more verbose
kb.rule(
    when=("is-bird", "?x"),
    then=("can-fly", "?x", 0.9)
)

4. Leverage Query Chaining

# Powerful filtering
experts = (
    kb.where("has-skill")
    .with_args("python")
    .having_degree('>', 0.8)
    .map(lambda f: {"name": f.args[0], "level": f.degree})
)

Type Hints

from fuzzy_infer.fluent import FluentKB, FluentQueryResult, FuzzySession
from typing import List

def process_kb(kb: FluentKB) -> FluentQueryResult:
    return kb.infer().where("result")

def with_session() -> List[Fact]:
    with FuzzySession() as session:
        session.fact("test", ["data"])
        return session.query("test").facts