Day 8: Handheld Halting

Classes:

Operation(value)	Represent an operation corresponding to an instruction.
Instruction(operation, argument)	Represent an instruction of the boot code.

Functions:

parse_line(line)	Parse a line of the boot code into an instruction.
parse(lines)	Parse the boot code given as lines.
execute_instructions(instructions)	Execute the boot code given as instructions.

class Operation(value)

Represent an operation corresponding to an instruction.

Attributes:

NOP
ACC
JMP

NOP = 'nop'

ACC = 'acc'

JMP = 'jmp'

class Instruction(operation: Operation, argument: int)

Represent an instruction of the boot code.

Attributes:

operation	the corresponding operation
argument	the argument to the operation

operation: Operation

the corresponding operation

argument: int

the argument to the operation

parse_line(line: str) → Instruction

Parse a line of the boot code into an instruction.

Requires

• INSTRUCTION_RE.match(line)

parse(lines: Lines) → List[Instruction]

Parse the boot code given as lines.

Requires

• all(INSTRUCTION_RE.match(line) for line in lines)

Ensures

• len(lines) == len(result)

execute_instructions(instructions: List[Instruction]) → Optional[int]

Execute the boot code given as instructions.

Returns

The value in the accumulator just before an instruction is run for the second time

Requires

• all(
      0 <= i + instruction.argument < len(instructions)
      for i, instruction in enumerate(instructions)
      if instruction.operation == Operation.JMP
  )