Fixing parser error with read card

montepy/input_parser/input_syntax_reader.py

@@ -9,6 +9,7 @@
 from montepy.input_parser.input_file import MCNP_InputFile
 from montepy.input_parser.mcnp_input import Input, Message, ReadInput, Title
 from montepy.input_parser.read_parser import ReadParser
+from montepy.utilities import is_comment
 import os
 import warnings
 
@@ -88,20 +89,6 @@ def read_front_matters(fh, mcnp_version):
             break
 
 
-def is_comment(line):
-    """"""
-    upper_start = line[0 : BLANK_SPACE_CONTINUE + 1].upper()
-    non_blank_comment = upper_start and line.lstrip().upper().startswith("C ")
-    if non_blank_comment:
-        return True
-    blank_comment = (
-        "C\n" == upper_start.lstrip()
-        or "C\r\n" == upper_start.lstrip()
-        or ("C" == upper_start and "\n" not in line)
-    )
-    return blank_comment or non_blank_comment
-
-
 def read_data(fh, mcnp_version, block_type=None, recursion=False):
     """
     Reads the bulk of an MCNP file for all of the MCNP data.

montepy/input_parser/mcnp_input.py

@@ -295,16 +295,28 @@ class ReadInput(Input):
 
     def __init__(self, input_lines, block_type, input_file=None, lineno=None):
         super().__init__(input_lines, block_type, input_file, lineno)
+        if not self.is_read_input(input_lines):
+            raise ValueError("Not a valid Read Input")
         parse_result = self._parser.parse(self.tokenize(), self)
-        first_word = input_lines[0].split()[0].lower()
         if not parse_result:
-            if first_word != "read":
-                raise ValueError("Not a valid Read Input")
-            else:
-                raise ParsingError(self, "", self._parser.log.clear_queue())
+            raise ParsingError(self, "", self._parser.log.clear_queue())
         self._tree = parse_result
         self._parameters = self._tree["parameters"]
 
+    @staticmethod
+    def is_read_input(input_lines):
+        first_non_comment = ""
+        for line in input_lines:
+            if not is_comment(line):
+                first_non_comment = line
+                break
+        words = first_non_comment.split()
+        if len(words) > 0:
+            first_word = words[0].lower()
+            return first_word == "read"
+        # this is a fall through catch that only happens for a blank input
+        return False  # pragma: no cover
+
     @property
     def file_name(self):
         """

montepy/input_parser/parser_base.py

@@ -374,6 +374,7 @@ def file_name(self, p):
         "SURFACE_TYPE",
         "THERMAL_LAW",
         "ZAID",
+        "NUMBER_WORD",
     )
     def file_atom(self, p):
         return p[0]

montepy/utilities.py

@@ -1,4 +1,5 @@
 # Copyright 2024, Battelle Energy Alliance, LLC All Rights Reserved.
+from montepy.constants import BLANK_SPACE_CONTINUE
 import functools
 import re
 
@@ -31,6 +32,25 @@ def fortran_float(number_string):
             raise ValueError(f"Value Not parsable as float: {number_string}") from e
 
 
+def is_comment(line):
+    """
+    Determines if the line is a ``C comment`` style comment.
+
+    :param line: the line to analyze
+    :type line: str
+    :returns: True if the line is a comment
+    :rtype: bool
+    """
+    upper_start = line[0 : BLANK_SPACE_CONTINUE + 1].upper()
+    non_blank_comment = upper_start and line.lstrip().upper().startswith("C ")
+    if non_blank_comment:
+        return True
+    blank_comment = ("C" == upper_start.strip() and "\n" in line) or (
+        "C" == upper_start and "\n" not in line
+    )
+    return blank_comment
+
+
 def make_prop_val_node(
     hidden_param, types=None, base_type=None, validator=None, deletable=False
 ):

tests/constants.py

@@ -23,6 +23,7 @@
     "testReadTarget.imcnp",
     "bad_encoding.imcnp",
     "unicode.imcnp",
+    "file2read.imcnp",
 }
 
 BAD_ENCODING_FILES = {

tests/inputs/file2read.imcnp

@@ -0,0 +1,2 @@
+1 0 -1
+c

tests/inputs/readEdgeCase.imcnp

@@ -0,0 +1,7 @@
+Testing read card
+C this is a comment
+read file=file2read.imcnp
+
+1 so 0.5 
+
+mode n

tests/test_edge_cases.py

@@ -177,3 +177,8 @@ def test_geometry_comments(self):
         # this step caused an error for #163
         cell.comments
         cell._tree.format()
+
+    def test_bad_read(self):
+        problem = montepy.read_input(
+            os.path.join("tests", "inputs", "readEdgeCase.imcnp")
+        )

tests/test_syntax_parsing.py

@@ -1101,6 +1101,10 @@ def testReadCardConfusions(self):
             input = ReadInput([f"Read FILE={file}"], BlockType.CELL)
             self.assertEqual(input.file_name, file)
 
+    def testReadCardBadSyntax(self):
+        with self.assertRaises(ParsingError):
+            card = ReadInput(["Read 1"], BlockType.CELL)
+
     def testTitleFinder(self):
         test_title = "Richard Stallman writes GNU"
         test_string = f"""{test_title}