in feature/plural/plural.go [170:256]
func matchPlural(p *Rules, index compact.ID, n, f, v int) Form {
nMask := p.inclusionMasks[n%maxMod]
// Compute the fMask inline in the rules below, as it is relatively rare.
// fMask := p.inclusionMasks[f%maxMod]
vMask := p.inclusionMasks[v%maxMod]
// Do the matching
offset := p.langToIndex[index]
rules := p.rules[p.index[offset]:p.index[offset+1]]
for i := 0; i < len(rules); i++ {
rule := rules[i]
setBit := uint64(1 << rule.setID)
var skip bool
switch op := opID(rule.cat >> opShift); op {
case opI: // i = x
skip = n >= numN || nMask&setBit == 0
case opI | opNotEqual: // i != x
skip = n < numN && nMask&setBit != 0
case opI | opMod: // i % m = x
skip = nMask&setBit == 0
case opI | opMod | opNotEqual: // i % m != x
skip = nMask&setBit != 0
case opN: // n = x
skip = f != 0 || n >= numN || nMask&setBit == 0
case opN | opNotEqual: // n != x
skip = f == 0 && n < numN && nMask&setBit != 0
case opN | opMod: // n % m = x
skip = f != 0 || nMask&setBit == 0
case opN | opMod | opNotEqual: // n % m != x
skip = f == 0 && nMask&setBit != 0
case opF: // f = x
skip = f >= numN || p.inclusionMasks[f%maxMod]&setBit == 0
case opF | opNotEqual: // f != x
skip = f < numN && p.inclusionMasks[f%maxMod]&setBit != 0
case opF | opMod: // f % m = x
skip = p.inclusionMasks[f%maxMod]&setBit == 0
case opF | opMod | opNotEqual: // f % m != x
skip = p.inclusionMasks[f%maxMod]&setBit != 0
case opV: // v = x
skip = v < numN && vMask&setBit == 0
case opV | opNotEqual: // v != x
skip = v < numN && vMask&setBit != 0
case opW: // w == 0
skip = f != 0
case opW | opNotEqual: // w != 0
skip = f == 0
// Hard-wired rules that cannot be handled by our algorithm.
case opBretonM:
skip = f != 0 || n == 0 || n%1000000 != 0
case opAzerbaijan00s:
// 100,200,300,400,500,600,700,800,900
skip = n == 0 || n >= 1000 || n%100 != 0
case opItalian800:
skip = (f != 0 || n >= numN || nMask&setBit == 0) && n != 800
}
if skip {
// advance over AND entries.
for ; i < len(rules) && rules[i].cat&formMask == andNext; i++ {
}
continue
}
// return if we have a final entry.
if cat := rule.cat & formMask; cat != andNext {
return Form(cat)
}
}
return Other
}