import re
snake_case_pattern = re.compile(r'(?<!^)(?=[A-Z])')

def pascal_to_snake(v):
  name = snake_case_pattern.sub('_', v).lower()
  return name

token_simple_expr = [
  ["Mul", "*"],
  ["Div", "/"],
  ["Mod", "%"],
  ["LeftShift", "<<"],
  ["RightShift", ">>"],
  ["FirstMul = TK_Mul", "SPECIAL"],
  ["LastMul = TK_RightShift", "SPECIAL"],
  ["Add", "+"],
  ["Sub", "-"],
  ["FirstAdd = TK_Add", "SPECIAL"],
  ["LastAdd = TK_Sub", "SPECIAL"],
  ["Equals", "=="],
  ["LesserThenOrEqual", "<="],
  ["GreaterThenOrEqual", ">="],
  ["LesserThen", "<"],
  ["GreaterThen", ">"],
  ["NotEquals", "!="],
  ["FirstCompare = TK_Equals", "SPECIAL"],
  ["LastCompare = TK_NotEquals", "SPECIAL"],
  ["BitAnd", "&"],
  ["BitOr", "|"],
  ["BitXor", "^"],
  ["And", "&&"],
  ["Or", "||"],
  ["FirstLogical = TK_BitAnd", "SPECIAL"],
  ["LastLogical = TK_Or", "SPECIAL"],

  ["Neg", "~"],
  ["Not", "!"],
  ["Decrement", "--"],
  ["Increment", "++"],
  ["PostDecrement", "--"],
  ["PostIncrement", "++"],
]

token_assign_expr = [
  ["Assign", "="],
  ["ColonAssign", ":="],
  ["DivAssign", "/="],
  ["MulAssign", "*="],
  ["ModAssign", "%="],
  ["SubAssign", "-="],
  ["AddAssign", "+="],
  ["AndAssign", "&="],
  ["OrAssign", "|="],
  ["XorAssign", "^="],
  ["LeftShiftAssign", "<<="],
  ["RightShiftAssign", ">>="],
  ["FirstAssign = TK_Assign", "SPECIAL"],
  ["LastAssign = TK_RightShiftAssign", "SPECIAL"],
]

token_rest = [
  ["OpenParen", "("],
  ["CloseParen", ")"],
  ["OpenBrace", "{"],
  ["CloseBrace", "}"],
  ["OpenBracket", "["],
  ["CloseBracket", "]"],
  ["Comma", ","],
  ["Pound", "#"],
  ["Question", "?"],
  ["ThreeDots", "..."],
  ["Semicolon", ";"],
  ["Dot", "."],
  ["TwoDots", ".."],
  ["NewLine", "[NewLine]"],
  ["Colon", ":"],
  ["DoubleColon", "::"],
  ["At", "@"],
  ["Arrow", "->"],
  ["ExprSizeof", "[SizeOf]"],
  ["DocComment", "[///]"],
  ["Comment", "//"],
  ["Identifier", "[Ident]"],
  ["UnicodeLit", "[Unicode]"],
  ["StringLit", "[String]"],
  ["Error", "[Error]"],
  ["Float", "[Float]"],
  ["Integer", "[Int]"],
  ["Keyword", "[Keyword]"],
]

token_kinds = token_simple_expr + token_assign_expr + token_rest

keywords = [
  "struct",
  "union",
  "true",
  "default",
  "break",
  "false",
  "return",
  "switch",
  "Assert",
  "if",
  "elif",
  "pass",
  "else",
  "for",
  "enum",
]

interns = [
  "SizeOf",
  "Length",
  "AlignOf",
  "foreign",
  "strict",
  "void",
  "flag",
  "it",
]