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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
--~ ]])
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