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63 lines
2.7 KiB
Python
63 lines
2.7 KiB
Python
from collections.abc import Iterator, Sequence
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from typing import Protocol
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from graphon.nodes.base.variable_template_parser import extract_selectors_from_template
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from graphon.variables.segments import Segment
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from graphon.variables.template_resolution import VARIABLE_PATTERN
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type TemplateValue = str | Sequence[str] | int | float | None
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class TemplateVariablePool(Protocol):
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def get(self, selector: Sequence[str], /) -> Segment | None: ...
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def template_value_selectors(value: TemplateValue) -> Iterator[list[str]]:
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"""Extract workflow references from a scalar string or string sequence.
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Preconditions: ``value`` is a validated metadata condition value.
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Postconditions: Yield selectors without changing the value; constants
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yield nothing.
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"""
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values = [value] if isinstance(value, str) else value
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if isinstance(values, Sequence):
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for template in values:
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for reference in extract_selectors_from_template(template):
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yield list(reference.value_selector)
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def resolve_template_value(value: TemplateValue, variable_pool: TemplateVariablePool) -> TemplateValue:
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"""Resolve scalar values and string sequences against a workflow variable pool.
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Preconditions: ``value`` is a validated metadata condition value and the
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pool belongs to the current run.
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Postconditions: Return the resolved value without changing either input.
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A whole scalar reference retains its string or numeric type;
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interpolated text and elements of string lists remain strings. Missing
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references fail explicitly rather than becoming literal selector text.
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"""
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def get_segment(selector: str) -> Segment:
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"""Return an existing dot-separated selector or raise ``ValueError``."""
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segment = variable_pool.get(selector.split("."))
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if segment is None:
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raise ValueError(f"Workflow variable {selector} is not available.")
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return segment
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def resolve_template(template: str) -> str | int | float | None:
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"""Resolve a string template without changing the pool; fail on missing refs."""
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if match := VARIABLE_PATTERN.fullmatch(template):
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resolved = get_segment(match.group(1)).to_object()
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if resolved is None or isinstance(resolved, str | float):
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return resolved
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if isinstance(resolved, int) and not isinstance(resolved, bool):
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return resolved
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return str(resolved)
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return VARIABLE_PATTERN.sub(lambda match: get_segment(match.group(1)).text, template)
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if isinstance(value, str):
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return resolve_template(value)
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if isinstance(value, Sequence):
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return [str(resolve_template(item)) for item in value]
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return value
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