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-rw-r--r--Master/texmf-dist/tex/context/base/util-str.lua107
1 files changed, 107 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/context/base/util-str.lua b/Master/texmf-dist/tex/context/base/util-str.lua
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+if not modules then modules = { } end modules ['util-str'] = {
+ version = 1.001,
+ comment = "companion to luat-lib.mkiv",
+ author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+ copyright = "PRAGMA ADE / ConTeXt Development Team",
+ license = "see context related readme files"
+}
+
+utilities = utilities or {}
+utilities.strings = utilities.strings or { }
+local strings = utilities.strings
+
+local find, gsub, rep = string.find, string.gsub, string.rep
+local Cs, C, Cp, P, Carg = lpeg.Cs, lpeg.C, lpeg.Cp, lpeg.P, lpeg.Carg
+local patterns, lpegmatch = lpeg.patterns, lpeg.match
+
+-- str = " \n \ntest \n test\ntest "
+-- print("["..string.gsub(string.collapsecrlf(str),"\n","+").."]")
+
+local rubish = patterns.spaceortab^0 * patterns.newline
+local anyrubish = patterns.spaceortab + patterns.newline
+local anything = patterns.anything
+local stripped = (patterns.spaceortab^1 / "") * patterns.newline
+local leading = rubish^0 / ""
+local trailing = (anyrubish^1 * patterns.endofstring) / ""
+local redundant = rubish^3 / "\n"
+
+local pattern = Cs(leading * (trailing + redundant + stripped + anything)^0)
+
+function strings.collapsecrlf(str)
+ return lpegmatch(pattern,str)
+end
+
+-- The following functions might end up in another namespace.
+
+--~ function strings.tabtospace(str,tab)
+--~ -- we don't handle embedded newlines
+--~ while true do
+--~ local s = find(str,"\t")
+--~ if s then
+--~ if not tab then tab = 7 end -- only when found
+--~ local d = tab-(s-1) % tab
+--~ if d > 0 then
+--~ str = gsub(str,"\t",rep(" ",d),1)
+--~ else
+--~ str = gsub(str,"\t","",1)
+--~ end
+--~ else
+--~ break
+--~ end
+--~ end
+--~ return str
+--~ end
+
+local extra, tab, start = 0, 0, 4, 0
+
+local pattern =
+ Carg(1) / function(t)
+ extra, tab, start = 0, t or 7, 1
+ end
+ * Cs((
+ Cp() * patterns.tab / function(position)
+ local current = (position - start + 1) + extra
+ local spaces = tab-(current-1) % tab
+ if spaces > 0 then
+ extra = extra + spaces - 1
+ return rep(" ",spaces)
+ else
+ return ""
+ end
+ end
+ + patterns.newline * Cp() / function(position)
+ extra, start = 0, position
+ end
+ + patterns.anything
+ )^1)
+
+function strings.tabtospace(str,tab)
+ return lpegmatch(pattern,str,1,tab or 7)
+end
+
+--~ local t = {
+--~ "1234567123456712345671234567",
+--~ "\tb\tc",
+--~ "a\tb\tc",
+--~ "aa\tbb\tcc",
+--~ "aaa\tbbb\tccc",
+--~ "aaaa\tbbbb\tcccc",
+--~ "aaaaa\tbbbbb\tccccc",
+--~ "aaaaaa\tbbbbbb\tcccccc\n aaaaaa\tbbbbbb\tcccccc",
+--~ "one\n two\nxxx three\nxx four\nx five\nsix",
+--~ }
+--~ for k=1,#t do
+--~ print(strings.tabtospace(t[k]))
+--~ end
+
+function strings.striplong(str) -- strips all leading spaces
+ str = gsub(str,"^%s*","")
+ str = gsub(str,"[\n\r]+ *","\n")
+ return str
+end
+
+--~ local template = string.striplong([[
+--~ aaaa
+--~ bb
+--~ cccccc
+--~ ]])