time efficient julia string

string_process.jl

struct AString
    buf::Vector{Char}
end

function convert(::Type{AString}, str::String)
    n = ncodeunits(str)
    buf = Char[]
    i = 1
    while i <= n
        chr = str[i]::Char
        push!(buf, chr)
        i += ncodeunits(chr)
    end
    AString(buf)
end

@generated function control_char(::Val{Ch}) where {Ch}
    Meta.parse(String(['\'', '\\', Ch, '\'']))
end
macro a_str(s::String)
    chs = Char[]
    n = ncodeunits(s)
    i = 1
    quoted = false

    while i <= n
        if quoted
            if s[i] === '\\'
                push!(chs, '\\')
                i += 1
            else
                push!(chs, control_char(Val(s[i])))
                i += ncodeunits(s[i])
            end
            quoted = false
        elseif s[i] === '\\'
            quoted = true
            i += 1
        else
            push!(chs, s[i])
            i += ncodeunits(s[i])
        end

    end
    AString(chs)
end

function Base.show(io::IO, a::AString)
    print(io, '\"')
    for c in a.buf
        if c === '\"'
            print(io, '\\')
        end
        print(io, c)
    end
    print(io, '\"')
end

@eval function Base.$(:(==))(x::AString, y::AString)
    x.buf == y.buf
end

Base.length(a::AString) = length(a.buf)

function KMPSearch(pat::AString, txt::AString)
    M = length(pat)
    N = length(txt)
    lps = fill(1, M)
    j = 1
    computeLPSArray!(pat, M, lps)
    i = 1
    indices = Int32[]
    while i <= N
        if pat.buf[j] === txt.buf[i]
            i += 1
            j += 1
        end
        if j === M + 1
            push!(indices, i - j + 1)
            j = 1
        elseif i <= N && pat.buf[j] !== txt.buf[i]
            if j !== 1
                j = lps[j-1]
            else
                i += 1
            end
        end
    end
    indices
end

function computeLPSArray!(pat, M, lps)
    len = 1 # length of the previous longest prefix suffix 
    i = 2
    while i <= M
        if pat.buf[i] == pat.buf[len]
            len += 1
            lps[i] = len
            i += 1
        else
            if len != 1
                len = lps[len-1]
            else
                lps[i] = 1
                i += 1
            end
        end
    end
end

function split′(s::AString, sep::AString)
    indices = KMPSearch(sep, s)
    n_sep = length(sep)
    if isempty(indices)
        AString[s]
    else
        res = Vector{AString}(undef, length(indices) + 1)
        buf = s.buf
        push!(indices, length(s) + 1)
        last_i = 1
        for i in eachindex(indices)
            now = indices[i]
            res[i] = AString(buf[last_i:now-1])
            last_i = now + n_sep
        end
        res
    end
end

function startswith′(a::AString, prefix::AString)
    n1 = length(a)
    n2 = length(prefix)
    n1 < n2 && return false
    all(a.buf[i] === prefix.buf[i] for i in 1:n2)
end

const a = ARGS[1]
function f()
    z = 0
    for l in eachline(a::String)
        l = convert(AString, l)
        if startswith′(l, a"##")
            continue
        else
            d = split′(l, a"\t")
            dd = d[10:end]
            for i in 1:33
                ddd = dd[i]
                if split′(ddd, a":")[1] != a"./." && split′(ddd, a":")[1] != a"0/0"
                    z += length(l)
                    break
                end
            end
        end
    end
    println(z)
end

@time f()