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if not modules then modules = { } end modules ['l-string'] = {
version = 1.001,
comment = "companion to luat-lib.tex",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
local sub, gsub, find, match, gmatch, format, char, byte, rep = string.sub, string.gsub, string.find, string.match, string.gmatch, string.format, string.char, string.byte, string.rep
if not string.split then
-- this will be overloaded by a faster lpeg variant
function string:split(pattern)
if #self > 0 then
local t = { }
for s in gmatch(self..pattern,"(.-)"..pattern) do
t[#t+1] = s
end
return t
else
return { }
end
end
end
local chr_to_esc = {
["%"] = "%%",
["."] = "%.",
["+"] = "%+", ["-"] = "%-", ["*"] = "%*",
["^"] = "%^", ["$"] = "%$",
["["] = "%[", ["]"] = "%]",
["("] = "%(", [")"] = "%)",
["{"] = "%{", ["}"] = "%}"
}
string.chr_to_esc = chr_to_esc
function string:esc() -- variant 2
return (gsub(self,"(.)",chr_to_esc))
end
function string:unquote()
return (gsub(self,"^([\"\'])(.*)%1$","%2"))
end
function string:quote() -- we could use format("%q")
return '"' .. self:unquote() .. '"'
end
function string:count(pattern) -- variant 3
local n = 0
for _ in gmatch(self,pattern) do
n = n + 1
end
return n
end
function string:limit(n,sentinel)
if #self > n then
sentinel = sentinel or " ..."
return sub(self,1,(n-#sentinel)) .. sentinel
else
return self
end
end
function string:strip()
return (gsub(self,"^%s*(.-)%s*$", "%1"))
end
function string:is_empty()
return not find(find,"%S")
end
function string:enhance(pattern,action)
local ok, n = true, 0
while ok do
ok = false
self = gsub(self,pattern, function(...)
ok, n = true, n + 1
return action(...)
end)
end
return self, n
end
local chr_to_hex, hex_to_chr = { }, { }
for i=0,255 do
local c, h = char(i), format("%02X",i)
chr_to_hex[c], hex_to_chr[h] = h, c
end
function string:to_hex()
return (gsub(self or "","(.)",chr_to_hex))
end
function string:from_hex()
return (gsub(self or "","(..)",hex_to_chr))
end
if not string.characters then
local function nextchar(str, index)
index = index + 1
return (index <= #str) and index or nil, str:sub(index,index)
end
function string:characters()
return nextchar, self, 0
end
local function nextbyte(str, index)
index = index + 1
return (index <= #str) and index or nil, byte(str:sub(index,index))
end
function string:bytes()
return nextbyte, self, 0
end
end
-- we can use format for this (neg n)
function string:rpadd(n,chr)
local m = n-#self
if m > 0 then
return self .. self.rep(chr or " ",m)
else
return self
end
end
function string:lpadd(n,chr)
local m = n-#self
if m > 0 then
return self.rep(chr or " ",m) .. self
else
return self
end
end
string.padd = string.rpadd
function is_number(str) -- tonumber
return find(str,"^[%-%+]?[%d]-%.?[%d+]$") == 1
end
--~ print(is_number("1"))
--~ print(is_number("1.1"))
--~ print(is_number(".1"))
--~ print(is_number("-0.1"))
--~ print(is_number("+0.1"))
--~ print(is_number("-.1"))
--~ print(is_number("+.1"))
function string:split_settings() -- no {} handling, see l-aux for lpeg variant
if find(self,"=") then
local t = { }
for k,v in gmatch(self,"(%a+)=([^%,]*)") do
t[k] = v
end
return t
else
return nil
end
end
local patterns_escapes = {
["-"] = "%-",
["."] = "%.",
["+"] = "%+",
["*"] = "%*",
["%"] = "%%",
["("] = "%)",
[")"] = "%)",
["["] = "%[",
["]"] = "%]",
}
function string:pattesc()
return (gsub(self,".",patterns_escapes))
end
function string:tohash()
local t = { }
for s in gmatch(self,"([^, ]+)") do -- lpeg
t[s] = true
end
return t
end
local pattern = lpeg.Ct(lpeg.C(1)^0)
function string:totable()
return pattern:match(self)
end
--~ for _, str in ipairs {
--~ "1234567123456712345671234567",
--~ "a\tb\tc",
--~ "aa\tbb\tcc",
--~ "aaa\tbbb\tccc",
--~ "aaaa\tbbbb\tcccc",
--~ "aaaaa\tbbbbb\tccccc",
--~ "aaaaaa\tbbbbbb\tcccccc",
--~ } do print(string.tabtospace(str)) end
function string.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
function string:compactlong() -- strips newlines and leading spaces
self = gsub(self,"[\n\r]+ *","")
self = gsub(self,"^ *","")
return self
end
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