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-rw-r--r--macros/luatex/generic/cstypo/cstypo.lua176
1 files changed, 176 insertions, 0 deletions
diff --git a/macros/luatex/generic/cstypo/cstypo.lua b/macros/luatex/generic/cstypo/cstypo.lua
new file mode 100644
index 0000000000..4ad6f651fb
--- /dev/null
+++ b/macros/luatex/generic/cstypo/cstypo.lua
@@ -0,0 +1,176 @@
+--[[--
+(c) 2016 Václav Haisman
+
+This program can be redistributed and/or modified under the terms of the MIT
+license. See LICENSE file.
+--]]--
+
+local GLYPH = node.id("glyph")
+--print('GLYPH value: ', GLYPH)
+
+local GLUE = node.id("glue")
+--print('GLUE value: ', GLUE)
+
+local CZECH_ID = cstypo_czech_language_id
+--print('CZECH_ID value: ', CZECH_ID)
+
+local function prevent_single_letter (head)
+ while head do
+ -- glyph
+ if (head.id == GLYPH
+ -- and in Czech or unspecified (???)
+ and (head.lang == nil
+ or head.lang == CZECH_ID)) then
+ -- only if we are at one letter word
+ if unicode.utf8.match(unicode.utf8.char(head.char), "[zZsSuUkKoOvViI]") then
+ -- and left of it is either a space
+ if ((head.prev.id == GLUE
+ -- or one of '{[('
+ or (head.prev.id == GLYPH
+ and unicode.utf8.match(unicode.utf8.char(head.prev.char),
+ "[%[%]()%{%}]")))
+ -- and right of the one letter word is also a space
+ and head.next.id == GLUE) then
+ -- then avoid line break between the single letter word and the
+ -- word following it
+ local p = node.new("penalty")
+ p.penalty = 10000
+ node.insert_after(head, head, p)
+ --print('inserting penalty at ', head)
+ end
+ end
+ end
+ head = head.next
+ end
+ return true
+end
+
+function cstypo_single_letter_enable ()
+ print('cstypo: Enabling single letter hook.')
+ luatexbase.add_to_callback("pre_linebreak_filter", prevent_single_letter,
+ "cstyposingleletter")
+end
+
+function cstypo_single_letter_disable ()
+ print('cstypo: Disabling single letter hook.')
+ luatexbase.remove_from_callback("pre_linebreak_filter", "cstyposingleletter")
+end
+
+
+local function prevent_a_letter (head)
+ while head do
+ -- glyph
+ if (head.id == GLYPH
+ -- and in Czech or unspecified (???)
+ and (head.lang == nil
+ or head.lang == CZECH_ID)) then
+ -- only if we are at one letter word
+ if unicode.utf8.match(unicode.utf8.char(head.char), "[aA]") then
+ -- and previous is space
+ if ((head.prev.id == GLUE
+ -- or previous is one of '{[('
+ or (head.prev.id == GLYPH
+ and unicode.utf8.match(unicode.utf8.char(head.prev.char),
+ "[%[%]()%{%}]")))
+ -- and right of the one letter word is also a space
+ and head.next.id == GLUE) then
+ -- then avoid line break between the single letter word and the
+ -- word following it
+ local p = node.new("penalty")
+ p.penalty = 10000
+ node.insert_after(head, head, p)
+ end
+ end
+ end
+ head = head.next
+ end
+ return true
+end
+
+function cstypo_a_letter_enable ()
+ print('cstypo: Enabling \'a\' letter hook.')
+ luatexbase.add_to_callback("pre_linebreak_filter", prevent_a_letter,
+ "cstypoaletter")
+end
+
+function cstypo_a_letter_disable ()
+ print('cstypo: Disabling \'a\' letter hook.')
+ luatexbase.remove_from_callback("pre_linebreak_filter", "cstypoaletter")
+end
+
+
+local function prevent_percents (head)
+ while head do
+ -- glyph
+ if (head.id == GLYPH
+ -- and in Czech or unspecified (???)
+ and (head.lang == nil
+ or head.lang == CZECH_ID)) then
+ -- only if we are at percentage sign
+ if unicode.utf8.match(unicode.utf8.char(head.char), "[%%‰°℃℉]") then
+ -- and left of it is a space
+ if (head.prev.id == GLUE
+ -- and left of the space is a digit.
+ and head.prev.prev.id == GLYPH
+ and unicode.utf8.match(unicode.utf8.char(head.prev.prev.char),
+ "[0-9]")) then
+ local p = node.new("penalty")
+ p.penalty = 10000
+ node.insert_after(head.prev.prev, head.prev.prev, p)
+ end
+ end
+ end
+ head = head.next
+ end
+ return true
+end
+
+function cstypo_percents_enable()
+ print('cstypo: Enabling percents hook.')
+ luatexbase.add_to_callback("pre_linebreak_filter", prevent_percents,
+ "cstypopercents")
+end
+
+function cstypo_percents_disable()
+ print('cstypo: Disabling percents hook.')
+ luatexbase.remove_from_callback("pre_linebreak_filter", "cstypopercents")
+end
+
+
+local function prevent_paragraph (head)
+ while head do
+ -- glyph
+ if (head.id == GLYPH
+ -- and in Czech or unspecified (???)
+ and (head.lang == nil
+ or head.lang == CZECH_ID)) then
+ -- only if we are at paragraph symbol
+ if unicode.utf8.match(unicode.utf8.char(head.char), "[§]") then
+ -- and right of it is a space
+ if (head.next.id == GLUE
+ and (head.next.next.id == GLYPH
+ and unicode.utf8.match(unicode.utf8.char(head.next.next.char),
+ "[0-9]"))) then
+ -- then avoid line break between the paragraph and the number
+ -- following it
+ local p = node.new("penalty")
+ p.penalty = 10000
+ node.insert_after(head, head, p)
+ end
+ end
+ end
+ head = head.next
+ end
+ return true
+end
+
+function cstypo_paragraph_enable()
+ print('cstypo: Enabling paragraph hook.')
+ luatexbase.add_to_callback("pre_linebreak_filter", prevent_paragraph,
+ "cstypoparagraph")
+end
+
+function cstypo_paragraph_disable()
+ print('cstypo: Disabling paragraph hook.')
+ luatexbase.remove_from_callback("pre_linebreak_filter", "cstypoparagraph")
+end