31 lines
842 B
Plaintext
31 lines
842 B
Plaintext
program = _{ SOI ~ "\n"* ~ (stmt ~ "\n"+) * ~ stmt? ~ EOI }
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stmt = { ((label ~ ":")? ~ instruction)}
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instruction = {
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no_arg_instruction |
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arg_instruction ~ argument |
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jump_instruction ~ jump_argument |
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memory_location_instruction ~ memory_location |
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constant_arg_instruction ~ digit_literal
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}
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memory_location_instruction = {"STA"}
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constant_arg_instruction = {"BRZ" | "BRC" | "BRN"}
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jump_instruction = {"JMP"}
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arg_instruction = {"LDA" | "ADD" | "SUB"}
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no_arg_instruction = { "NOP" }
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jump_argument = { jump_location | label | memory_location }
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argument = { memory_location | digit_literal }
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memory_location = { "(" ~ ASCII_HEX_DIGIT ~")" }
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digit_literal = {"#" ~ ASCII_HEX_DIGIT}
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jump_location = { '0'..'9' | 'a'..'f' }
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label = { ASCII_ALPHA_UPPER+ }
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WHITESPACE = _{ " " | "\t" }
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COMMENT = _{"//" ~ (!"\n" ~ ANY)* }
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