func()

in language/match.go [553:660]

• 83 lines of code
• 36 McCabe index (conditional complexity)

func (m *bestMatch) update(have *haveTag, tag language.Tag, maxScript language.Script, maxRegion language.Region, pin bool) {
	// Bail if the maximum attainable confidence is below that of the current best match.
	c := have.conf
	if c < m.conf {
		return
	}
	// Don't change the language once we already have found an exact match.
	if m.pinLanguage && tag.LangID != m.want.LangID {
		return
	}
	// Pin the region group if we are comparing tags for the same language.
	if tag.LangID == m.want.LangID && m.sameRegionGroup {
		_, sameGroup := regionGroupDist(m.pinnedRegion, have.maxRegion, have.maxScript, m.want.LangID)
		if !sameGroup {
			return
		}
	}
	if c == Exact && have.maxScript == maxScript {
		// If there is another language and then another entry of this language,
		// don't pin anything, otherwise pin the language.
		m.pinLanguage = pin
	}
	if equalsRest(have.tag, tag) {
	} else if have.maxScript != maxScript {
		// There is usually very little comprehension between different scripts.
		// In a few cases there may still be Low comprehension. This possibility
		// is pre-computed and stored in have.altScript.
		if Low < m.conf || have.altScript != maxScript {
			return
		}
		c = Low
	} else if have.maxRegion != maxRegion {
		if High < c {
			// There is usually a small difference between languages across regions.
			c = High
		}
	}

	// We store the results of the computations of the tie-breaker rules along
	// with the best match. There is no need to do the checks once we determine
	// we have a winner, but we do still need to do the tie-breaker computations.
	// We use "beaten" to keep track if we still need to do the checks.
	beaten := false // true if the new pair defeats the current one.
	if c != m.conf {
		if c < m.conf {
			return
		}
		beaten = true
	}

	// Tie-breaker rules:
	// We prefer if the pre-maximized language was specified and identical.
	origLang := have.tag.LangID == tag.LangID && tag.LangID != 0
	if !beaten && m.origLang != origLang {
		if m.origLang {
			return
		}
		beaten = true
	}

	// We prefer if the pre-maximized region was specified and identical.
	origReg := have.tag.RegionID == tag.RegionID && tag.RegionID != 0
	if !beaten && m.origReg != origReg {
		if m.origReg {
			return
		}
		beaten = true
	}

	regGroupDist, sameGroup := regionGroupDist(have.maxRegion, maxRegion, maxScript, tag.LangID)
	if !beaten && m.regGroupDist != regGroupDist {
		if regGroupDist > m.regGroupDist {
			return
		}
		beaten = true
	}

	paradigmReg := isParadigmLocale(tag.LangID, have.maxRegion)
	if !beaten && m.paradigmReg != paradigmReg {
		if !paradigmReg {
			return
		}
		beaten = true
	}

	// Next we prefer if the pre-maximized script was specified and identical.
	origScript := have.tag.ScriptID == tag.ScriptID && tag.ScriptID != 0
	if !beaten && m.origScript != origScript {
		if m.origScript {
			return
		}
		beaten = true
	}

	// Update m to the newly found best match.
	if beaten {
		m.have = have
		m.want = tag
		m.conf = c
		m.pinnedRegion = maxRegion
		m.sameRegionGroup = sameGroup
		m.origLang = origLang
		m.origReg = origReg
		m.paradigmReg = paradigmReg
		m.origScript = origScript
		m.regGroupDist = regGroupDist
	}
}