CB Repository

stri$ = "Tavuttaa merkkijonon suomen kielen tavutussääntöjen mukaisesti. Tämä ei ole täysin aukoton. Esimerkiksi nämä menee pieleen: demokratia, Citroën."
MakeError HyphenateString(stri)

Function HyphenateString(stri$, mode$="-")
	//Hyphenates Finnish Text.
	//mode parameter controls the hyphenation:
	// - mode <> "": uses mode's value As a hyphen And returns the hyphenated Text. Length of mode can also be greater than 1.
	// - mode = "": returns a list of character positions where the Function suggests that a hyphen would be inserted. Example: "3,7,10".
	//Rules can be found from http://www.cs.hut.fi/Opinnot/T-106.1240/s2007/harjoitukset/kierros_2/harj_1/index.html (checked 2012-08-07),
	//but they are written in Finnish.
	original_stri$	= stri
	stri			= Lower(stri)
	vowels$			= "aeiouyåäö"
	result$			= ""
	hyphenated		= 1
	For i = 2 To Len(stri)
		chr1$	= Mid(stri, i-1,1)
		chr2$	= Mid(stri, i,1)
		If False=IsLetter(chr1) Or False=IsLetter(chr2) Then Goto continue
		
		//Rules
		hyphenate = False
		If InStr(vowels, chr1) And False = InStr(vowels, chr2) Then
			//A) Hyphenate If a consonant comes After a vowel.
			wovel_follows = False
			For n = i+1 To Len(stri)
				//Find Last consonant in a queue of consonants.
				chr_n$			= Mid(stri, n,1)
				wovel_follows	= InStr(vowels, chr_n)
				If wovel_follows Or False = IsLetter(chr_n) Then
					n-1
					Exit
				EndIf
			Next n
			If wovel_follows Then hyphenate = n - (n>=Len(stri)) //Only hyphenate If the queue of consonants is followed by a vowel.
		EndIf
		If InStr(vowels, chr1) And InStr(vowels, chr2) Then
			//B) Hyphenate If a vowel comes After a vowel, unless an exception happens.
			exception = False
			If chr1 = chr2 Then exception = True
			If chr2 = "i" Then exception = True
			If InStr("au,eu,ey,ie,iu,ou,uo,yö,äy,öy", chr1+chr2) Then exception = True
			If Not exception Then
				//No exceptions, so do hyphenating
				hyphenate = i
			Else
				//C) Exception For exceptions: If a vowel comes After the chr1+chr2 pair, hyphenate between chr2 And the vowel.
				If i = Len(stri) Then Exit
				chr3$ = Mid(stri, i+1,1)
				If InStr(vowels, chr3) Then hyphenate = i+1
			EndIf
		EndIf
		
		If hyphenate > hyphenated Then
			If mode = "" Then
				If result <> "" Then result + " "
				result + hyphenate
			Else
				result = result + Mid(original_stri, hyphenated, hyphenate-hyphenated) + mode
			EndIf
			hyphenated = hyphenate
		EndIf
		continue:
	Next i
	If mode <> "" Then result = result + Mid(original_stri, hyphenated)
	Return result
EndFunction

Function IsLetter(char$)
	//Checks If a given character is a-z, å, ä Or ö.
	//NOTE! Uppercase letters are considered As non-letters! 
	ascii = Asc(char)
	Return (ascii >= 97 And ascii <= 122) Or ascii = 228 Or ascii = 229 Or ascii = 246
EndFunction