95 lines
1.8 KiB
Python
95 lines
1.8 KiB
Python
"""
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Utility functions used for parsing.
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"""
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import struct
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def can_be_mark(argument):
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"""
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The ``argument`` can be interpreted as a Mark.
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"""
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a = ord("a")
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a_z = [chr(a + i) for i in range(26)]
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A = ord("A")
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A_Z = [chr(A + i) for i in range(26)]
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null = ord("0")
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null_9 = [chr(null + i) for i in range(10)]
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if(not argument[0] in a_z):
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return False
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for char in argument[1:]:
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if(not (char in a_z
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or char in A_Z
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or char in null_9
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or char == "_")):
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return False
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return True
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def can_convert_to_int(value):
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"""
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``value`` can be converted to an integer.
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**Note** that this returns ``True`` if the value is a
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character definition like ``'a'``.
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"""
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if(value.startswith("0x")):
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try:
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int(value[2:], 16)
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return True
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except:
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return False
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if(value.startswith("0b")):
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try:
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int(value[2:], 2)
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return True
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except:
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return False
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if(value.startswith("'") and value.endswith("'")):
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if(len(value) == 3):
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return True
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if(len(value) == 4):
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if(value[1:-1] in {"\\n", "\\r", "\\t"}):
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return True
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return False
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try:
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int(value)
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return True
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except:
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return False
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def autoint(value):
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"""
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Convert ``value`` to an integer automatically.
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"""
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escape_sequences = {"\\n": "\n", "\\r": "\r", "\\t":"\t"}
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if(value.startswith("0x")):
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return int(value[2:], 16)
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if(value.startswith("0b")):
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return int(value[2:], 2)
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if(value.startswith("'") and value.endswith("'")):
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if(len(value) == 3):
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return ord(value[1:-1])
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if(len(value) == 4):
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if(value[1:-1] in escape_sequences):
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return ord(escape_sequences[value[1:-1]])
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return int(value)
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def int16_2_bytes(value):
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"""
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Return the bytes representation of a 16bit unsigned
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integer in 8bit words.
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"""
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if(value < 0):
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return struct.pack("<h", value)
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return struct.pack("<H", value)
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