advent8.jl

function getop(op)
    op == :inc && return +
    op == :dec && return -
    eval(Base, op)
end
function eval_instr(instr, vars)
    lhs, op, rhs = split(instr, " ")
    slhs = Symbol(lhs)
    val1 = get!(vars, slhs, 0)
    val2 = parse(Int, rhs)
    opval = getop(Symbol(op))
    opval(val1, val2), slhs
end

function eval_program(program, vars)
    maxi = typemin(Int)
    for line in split(program, "\n")
        isempty(line) && continue
        instr, cond = strip.(split(line, "if"))
        condval, lhs = eval_instr(cond, vars)
        if condval
            val, lhs = eval_instr(instr, vars)
            maxi = max(maxi, val)
            vars[lhs] = val
        end
    end
    maxi
end
program = readstring("puzzle8.txt")
vars = Dict{Symbol, Int}()
currentmax = maximum(values(vars))
maximax = eval_program(program, vars)