Files

92 lines
2.9 KiB
Python

from typing import Dict, List, Mapping, Optional
import bashlex
from . import bashlex_eval
class EnvironmentParseError(Exception):
pass
def split_env_items(env_string: str) -> List[str]:
"""Splits space-separated variable assignments into a list of individual assignments.
>>> split_env_items('VAR=abc')
['VAR=abc']
>>> split_env_items('VAR="a string" THING=3')
['VAR="a string"', 'THING=3']
>>> split_env_items('VAR="a string" THING=\\'single "quotes"\\'')
['VAR="a string"', 'THING=\\'single "quotes"\\'']
>>> split_env_items('VAR="dont \\\\"forget\\\\" about backslashes"')
['VAR="dont \\\\"forget\\\\" about backslashes"']
>>> split_env_items('PATH="$PATH;/opt/cibw_test_path"')
['PATH="$PATH;/opt/cibw_test_path"']
>>> split_env_items('PATH2="something with spaces"')
['PATH2="something with spaces"']
"""
if not env_string:
return []
command_node = bashlex.parsesingle(env_string)
result = []
for word_node in command_node.parts:
part_string = env_string[word_node.pos[0] : word_node.pos[1]]
result.append(part_string)
return result
class EnvironmentAssignment:
def __init__(self, assignment: str):
name, equals, value = assignment.partition("=")
if not equals:
raise EnvironmentParseError(assignment)
self.name = name
self.value = value
def evaluated_value(
self,
environment: Dict[str, str],
executor: Optional[bashlex_eval.EnvironmentExecutor] = None,
) -> str:
"""Returns the value of this assignment, as evaluated in the environment"""
return bashlex_eval.evaluate(self.value, environment=environment, executor=executor)
def as_shell_assignment(self) -> str:
return f"export {self.name}={self.value}"
def __repr__(self) -> str:
return f"{self.name}={self.value}"
class ParsedEnvironment:
def __init__(self, assignments: List[EnvironmentAssignment]):
self.assignments = assignments
def as_dictionary(
self,
prev_environment: Mapping[str, str],
executor: Optional[bashlex_eval.EnvironmentExecutor] = None,
) -> Dict[str, str]:
environment = dict(**prev_environment)
for assignment in self.assignments:
value = assignment.evaluated_value(environment=environment, executor=executor)
environment[assignment.name] = value
return environment
def as_shell_commands(self) -> List[str]:
return [a.as_shell_assignment() for a in self.assignments]
def __repr__(self) -> str:
return f"ParsedEnvironment({[repr(a) for a in self.assignments]!r})"
def parse_environment(env_string: str) -> ParsedEnvironment:
env_items = split_env_items(env_string)
assignments = [EnvironmentAssignment(item) for item in env_items]
return ParsedEnvironment(assignments=assignments)