slides' `startLocation` returns wrong index

[yoinked-h]

intended:
a slide written as 8-4[4:3] returns a start position with index = 7 and a slide written as 1-4[4:3] returns a start position with index = 0

actual:
both slides return index=0, but the note location is correct (e.g. the star goes to index=7, but the slide starts from index=0)

test file:

&title=title
&artist=artist
&first=1.01
&des=des
&clock_count=16
&lv_7=14?
&inote_7=(120)
{4}
8-4[4:3],,,,
E

js impl:

function simai_parse(text) {
    const simai = new SimaiFile(text)
    let chartk = 'inote_7'
    const chart = SimaiConvert.deserialize(simai.getValue(chartk))
    console.log("orig");
    console.log(chart)
    return chart
}