mirror of
https://github.com/rclone/rclone.git
synced 2024-11-25 18:04:55 +01:00
235 lines
6.3 KiB
Go
235 lines
6.3 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
//go:generate go run gen.go gen_common.go
|
|
|
|
// Package plural provides utilities for handling linguistic plurals in text.
|
|
//
|
|
// The definitions in this package are based on the plural rule handling defined
|
|
// in CLDR. See
|
|
// http://unicode.org/reports/tr35/tr35-numbers.html#Language_Plural_Rules for
|
|
// details.
|
|
package plural
|
|
|
|
import (
|
|
"golang.org/x/text/language"
|
|
)
|
|
|
|
// Rules defines the plural rules for all languages for a certain plural type.
|
|
//
|
|
//
|
|
// This package is UNDER CONSTRUCTION and its API may change.
|
|
type Rules struct {
|
|
rules []pluralCheck
|
|
index []byte
|
|
langToIndex []byte
|
|
inclusionMasks []uint64
|
|
}
|
|
|
|
var (
|
|
// Cardinal defines the plural rules for numbers indicating quantities.
|
|
Cardinal *Rules = cardinal
|
|
|
|
// Ordinal defines the plural rules for numbers indicating position
|
|
// (first, second, etc.).
|
|
Ordinal *Rules = ordinal
|
|
|
|
ordinal = &Rules{
|
|
ordinalRules,
|
|
ordinalIndex,
|
|
ordinalLangToIndex,
|
|
ordinalInclusionMasks[:],
|
|
}
|
|
|
|
cardinal = &Rules{
|
|
cardinalRules,
|
|
cardinalIndex,
|
|
cardinalLangToIndex,
|
|
cardinalInclusionMasks[:],
|
|
}
|
|
)
|
|
|
|
// getIntApprox converts the digits in slice digits[start:end] to an integer
|
|
// according to the following rules:
|
|
// - Let i be asInt(digits[start:end]), where out-of-range digits are assumed
|
|
// to be zero.
|
|
// - Result n is big if i / 10^nMod > 1.
|
|
// - Otherwise the result is i % 10^nMod.
|
|
//
|
|
// For example, if digits is {1, 2, 3} and start:end is 0:5, then the result
|
|
// for various values of nMod is:
|
|
// - when nMod == 2, n == big
|
|
// - when nMod == 3, n == big
|
|
// - when nMod == 4, n == big
|
|
// - when nMod == 5, n == 12300
|
|
// - when nMod == 6, n == 12300
|
|
// - when nMod == 7, n == 12300
|
|
func getIntApprox(digits []byte, start, end, nMod, big int) (n int) {
|
|
// Leading 0 digits just result in 0.
|
|
p := start
|
|
if p < 0 {
|
|
p = 0
|
|
}
|
|
// Range only over the part for which we have digits.
|
|
mid := end
|
|
if mid >= len(digits) {
|
|
mid = len(digits)
|
|
}
|
|
// Check digits more significant that nMod.
|
|
if q := end - nMod; q > 0 {
|
|
if q > mid {
|
|
q = mid
|
|
}
|
|
for ; p < q; p++ {
|
|
if digits[p] != 0 {
|
|
return big
|
|
}
|
|
}
|
|
}
|
|
for ; p < mid; p++ {
|
|
n = 10*n + int(digits[p])
|
|
}
|
|
// Multiply for trailing zeros.
|
|
for ; p < end; p++ {
|
|
n *= 10
|
|
}
|
|
return n
|
|
}
|
|
|
|
// MatchDigits computes the plural form for the given language and the given
|
|
// decimal floating point digits. The digits are stored in big-endian order and
|
|
// are of value byte(0) - byte(9). The floating point position is indicated by
|
|
// exp and the number of visible decimals is scale. All leading and trailing
|
|
// zeros may be omitted from digits.
|
|
//
|
|
// The following table contains examples of possible arguments to represent
|
|
// the given numbers.
|
|
// decimal digits exp scale
|
|
// 123 []byte{1, 2, 3} 3 0
|
|
// 123.4 []byte{1, 2, 3, 4} 3 1
|
|
// 123.40 []byte{1, 2, 3, 4} 3 2
|
|
// 100000 []byte{1} 6......0
|
|
// 100000.00 []byte{1} 6......3
|
|
func (p *Rules) MatchDigits(t language.Tag, digits []byte, exp, scale int) Form {
|
|
index, _ := language.CompactIndex(t)
|
|
endN := len(digits) + exp
|
|
|
|
// Differentiate up to including mod 1000000 for the integer part.
|
|
n := getIntApprox(digits, 0, endN, 6, 1000000)
|
|
|
|
// Differentiate up to including mod 100 for the fractional part.
|
|
f := getIntApprox(digits, endN, endN+scale, 2, 100)
|
|
|
|
return matchPlural(p, index, n, f, scale)
|
|
}
|
|
|
|
func validForms(p *Rules, t language.Tag) (forms []Form) {
|
|
index, _ := language.CompactIndex(t)
|
|
offset := p.langToIndex[index]
|
|
rules := p.rules[p.index[offset]:p.index[offset+1]]
|
|
|
|
forms = append(forms, Other)
|
|
last := Other
|
|
for _, r := range rules {
|
|
if cat := Form(r.cat & formMask); cat != andNext && last != cat {
|
|
forms = append(forms, cat)
|
|
last = cat
|
|
}
|
|
}
|
|
return forms
|
|
}
|
|
|
|
func (p *Rules) matchComponents(t language.Tag, n, f, scale int) Form {
|
|
index, _ := language.CompactIndex(t)
|
|
return matchPlural(p, index, n, f, scale)
|
|
}
|
|
|
|
func matchPlural(p *Rules, index int, 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
|
|
}
|