Fix issue with shortcut recompression

montepy/input_parser/input_reader.py

@@ -3,15 +3,17 @@
 from montepy.constants import DEFAULT_VERSION
 
 
-def read_input(input_file, mcnp_version=DEFAULT_VERSION, replace=True):
+def read_input(destination, mcnp_version=DEFAULT_VERSION, replace=True):
  """
  Reads the specified MCNP Input file.
 
  The MCNP version must be a three component tuple e.g., (6, 2, 0) and (5, 1, 60).
 
+ .. note::
+ if a stream is provided. It will not be closed by this function.
 
- :param input_file: the path to the input file to read.
- :type input_file: str
+ :param destination: the path to the input file to read, or a readable stream.
+ :type destination: io.TextIOBase, str, os.PathLike
  :param mcnp_version: The version of MCNP that the input is intended for.
  :type mcnp_version: tuple
  :returns: The MCNP_Problem instance representing this file.
@@ -24,7 +26,7 @@ def read_input(input_file, mcnp_version=DEFAULT_VERSION, replace=True):
  :raises BrokenObjectLinkError: If a reference is made to an object that is not in the input file.
  :raises UnknownElement: If an isotope is specified for an unknown element.
  """
- problem = mcnp_problem.MCNP_Problem(input_file)
+ problem = mcnp_problem.MCNP_Problem(destination)
  problem.mcnp_version = mcnp_version
  problem.parse_input(replace=replace)
  return problem

montepy/input_parser/syntax_node.py

@@ -1834,7 +1834,7 @@ def _can_consume_node(self, node, direction, last_edge_shortcut=False):
  :type node: ValueNode
  :param direction: the direct to go in. Must be in {-1, 1}
  :type direction: int
- :param last_edge_shortcut: Whether or the previous node in the list was
+ :param last_edge_shortcut: Whether or not the previous node in the list was
  part of a different shortcut
  :type last_edge_shortcut: bool
  :returns: true it can be consumed.
@@ -1967,7 +1967,24 @@ def _format_jump(self):
  return f"{num_jumps.format()}{j}"
 
  def _format_repeat(self, leading_node=None):
- if leading_node is not None:
+ def can_use_last_node(node):
+ """Last node can be used if
+ - it's a basic ValueNode
+ - it's a different shortcut that concludes itself well.
+ - it's also a repeat, with the same edge values.
+ """
+ return isinstance(node, ValueNode) or (
+ isinstance(node, type(self))
+ and (
+ leading_node._type != Shortcuts.REPEAT
+ or (
+ leading_node._type == Shortcuts.REPEAT
+ and math.isclose(self.nodes[0].value, node.nodes[-1].value)
+ )
+ )
+ )
+
+ if can_use_last_node(leading_node):
  first_val = ""
  num_extra = 0
  else:

montepy/mcnp_problem.py

@@ -23,12 +23,18 @@ class MCNP_Problem:
  """
  A class to represent an entire MCNP problem in a semantic way.
 
- :param file_name: the path to the file that will be read.
- :type file_name: str
+ .. note::
+ If a stream is provided. It will not be closed by this function.
+
+ :param destination: the path to the input file to read, or a readable stream.
+ :type destination: io.TextIOBase, str, os.PathLike
  """
 
- def __init__(self, file_name):
- self._input_file = MCNP_InputFile(file_name)
+ def __init__(self, destination):
+ if hasattr(destination, "read") and callable(getattr(destination, "read")):
+ self._input_file = MCNP_InputFile.from_open_stream(destination)
+ elif isinstance(destination, (str, os.PathLike)):
+ self._input_file = MCNP_InputFile(destination)
  self._title = None
  self._message = None
  self._print_in_data_block = CellDataPrintController()

tests/inputs/test_importance.imcnp

@@ -41,7 +41,7 @@ MT3 lwtr.23t
 C execution
 ksrc 0 0 0
 imp:n,p 1 1 1 0 3
-imp:e 0 0 0 1 2
+imp:e 0 2r 1 r
 kcode 100000 1.000 50 1050
 phys:p j 1 2j 1
 mode n p e

tests/test_integration.py

@@ -1,6 +1,7 @@
 # Copyright 2024, Battelle Energy Alliance, LLC All Rights Reserved.
 import copy
 import io
+from pathlib import Path
 
 import pytest
 import os
@@ -17,6 +18,8 @@
 from montepy.particle import Particle
 import numpy as np
 
+from tests import constants
+
 
 @pytest.fixture(scope="module")
 def simple_problem():
@@ -481,7 +484,7 @@ def test_importance_format_unmutated(importance_problem):
  print(output)
  assert len(output) == 2
  assert "imp:n,p 1 1 1 0 3" == output[0]
- assert "imp:e 0 0 0 1 2" == output[1]
+ assert "imp:e 0 2r 1 r" == output[1]
 
 
 def test_importance_format_mutated(importance_problem):
@@ -1066,3 +1069,31 @@ def test_alternate_encoding():
  montepy.read_input(
  os.path.join("tests", "inputs", "bad_encoding.imcnp"), replace=True
  )
+
+
+@pytest.mark.parametrize(
+ "file",
+ {"tests/inputs/test_importance.imcnp"},
+ # set((Path("tests") / "inputs").iterdir())
+ # - {
+ # Path("tests") / "inputs" / p
+ # for p in constants.BAD_INPUTS | constants.IGNORE_FILES
+ # },
+)
+def test_read_write_cycle(file):
+ print(f"Testing against {file} *********************")
+ problem = montepy.read_input(file)
+ print(problem.cells._importance._real_tree[montepy.particle.Particle.ELECTRON])
+ print()
+ fh = io.StringIO()
+ problem.write_problem(fh)
+ fh.seek(0)
+ # test valid syntax
+ new_problem = montepy.MCNP_Problem("foo")
+ # verify lines are similar
+ fh.seek(0)
+ lines = [line.rstrip() for line in fh]
+ [print(line) for line in lines]
+ with open(file, "r") as gold_fh:
+ for gold_line, new_line in zip(gold_fh, lines):
+ assert new_line == gold_line.rstrip().expandtabs(8)