1# 2# Copyright (C) 2002-2011, International Business Machines Corporation and others. 3# All Rights Reserved. 4# 5# file: sent.txt 6# 7# ICU Sentence Break Rules 8# See Unicode Standard Annex #29. 9# These rules are based on UAX #29 Revision 19 for Unicode Version 6.1 10# 11 12 13# 14# Character categories as defined in TR 29 15# 16$CR = [\p{Sentence_Break = CR}]; 17$LF = [\p{Sentence_Break = LF}]; 18$Extend = [\p{Sentence_Break = Extend}]; 19$Sep = [\p{Sentence_Break = Sep}]; 20$Format = [\p{Sentence_Break = Format}]; 21$Sp = [\p{Sentence_Break = Sp}]; 22$Lower = [\p{Sentence_Break = Lower}]; 23$Upper = [\p{Sentence_Break = Upper}]; 24$OLetter = [\p{Sentence_Break = OLetter}]; 25$Numeric = [\p{Sentence_Break = Numeric}]; 26$ATerm = [\p{Sentence_Break = ATerm}]; 27$SContinue = [\p{Sentence_Break = SContinue}]; 28$STerm = [\p{Sentence_Break = STerm}]; 29$Close = [\p{Sentence_Break = Close}]; 30 31# 32# Define extended forms of the character classes, 33# incorporate trailing Extend or Format chars. 34# Rules 4 and 5. 35 36$SpEx = $Sp ($Extend | $Format)*; 37$LowerEx = $Lower ($Extend | $Format)*; 38$UpperEx = $Upper ($Extend | $Format)*; 39$OLetterEx = $OLetter ($Extend | $Format)*; 40$NumericEx = $Numeric ($Extend | $Format)*; 41$ATermEx = $ATerm ($Extend | $Format)*; 42$SContinueEx= $SContinue ($Extend | $Format)*; 43$STermEx = $STerm ($Extend | $Format)*; 44$CloseEx = $Close ($Extend | $Format)*; 45 46 47## ------------------------------------------------- 48 49!!chain; 50!!forward; 51 52# Rule 3 - break after separators. Keep CR/LF together. 53# 54$CR $LF; 55 56 57# Rule 4 - Break after $Sep. 58# Rule 5 - Ignore $Format and $Extend 59# 60[^$Sep $CR $LF]? ($Extend | $Format)*; 61 62 63# Rule 6 64$ATermEx $NumericEx; 65 66# Rule 7 67$UpperEx $ATermEx $UpperEx; 68 69#Rule 8 70$NotLettersEx = [^$OLetter $Upper $Lower $Sep $CR $LF $ATerm $STerm] ($Extend | $Format)*; 71$ATermEx $CloseEx* $SpEx* $NotLettersEx* $Lower; 72 73# Rule 8a 74($STermEx | $ATermEx) $CloseEx* $SpEx* ($SContinueEx | $STermEx | $ATermEx); 75 76#Rule 9, 10, 11 77($STermEx | $ATermEx) $CloseEx* $SpEx* ($Sep | $CR | $LF)?; 78 79#Rule 12 80[[^$STerm $ATerm $Close $Sp $Sep $LF $CR $Format $Extend]{bof}] ($Extend | $Format | $Close | $Sp)* .; 81[[^$STerm $ATerm $Close $Sp $Sep $LF $CR $Format $Extend]{bof}] ($Extend | $Format | $Close | $Sp)* ([$Sep $LF $CR {eof}] | $CR $LF){100}; 82 83## ------------------------------------------------- 84 85!!reverse; 86 87$SpEx_R = ($Extend | $Format)* $Sp; 88$ATermEx_R = ($Extend | $Format)* $ATerm; 89$STermEx_R = ($Extend | $Format)* $STerm; 90$CloseEx_R = ($Extend | $Format)* $Close; 91 92# 93# Reverse rules. 94# For now, use the old style inexact reverse rules, which are easier 95# to write, but less efficient. 96# TODO: exact reverse rules. It appears that exact reverse rules 97# may require improving support for look-ahead breaks in the 98# builder. Needs more investigation. 99# 100 101[{bof}] (.? | $LF $CR) [^$Sep $CR $LF]* [$Sep $CR $LF {eof}] ($SpEx_R* $CloseEx_R* ($STermEx_R | $ATermEx_R))*; 102#.*; 103 104# Explanation for this rule: 105# 106# It needs to back over 107# The $Sep at which we probably begin 108# All of the non $Sep chars leading to the preceding $Sep 109# The preceding $Sep, which will be the second one that the rule matches. 110# Any immediately preceding STerm or ATerm sequences. We need to see these 111# to get the correct rule status when moving forwards again. 112# 113# [{bof}] inhibit rule chaining. Without this, rule would loop on itself and match 114# the entire string. 115# 116# (.? | $LF $CR) Match one $Sep instance. Use .? rather than $Sep because position might be 117# at the beginning of the string at this point, and we don't want to fail. 118# Can only use {eof} once, and it is used later. 119# 120