update l-string

1 files changed, 66 insertions, 219 deletions

diff --git a/lualibs-string.lua b/lualibs-string.lua
index 9856d52..03616aa 100644
--- a/lualibs-string.lua
+++ b/lualibs-string.lua
@@ -6,8 +6,9 @@ if not modules then modules = { } end modules ['l-string'] = {
     license   = "see context related readme files"
 }
 
+local string = string
 local sub, gsub, find, match, gmatch, format, char, byte, rep, lower = string.sub, string.gsub, string.find, string.match, string.gmatch, string.format, string.char, string.byte, string.rep, string.lower
-local lpegmatch = lpeg.match
+local lpegmatch, S, C, Ct = lpeg.match, lpeg.S, lpeg.C, lpeg.Ct
 
 -- some functions may disappear as they are not used anywhere
 
@@ -15,196 +16,75 @@ 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
+    function string.split(str,pattern)
+        local t = { }
+        if #str > 0 then
+            local n = 1
+            for s in gmatch(str..pattern,"(.-)"..pattern) do
+                t[n] = s
+                n = n + 1
             end
-            return t
-        else
-            return { }
         end
+        return t
     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$","%2"))
+function string.unquoted(str)
+    return (gsub(str,"^([\"\'])(.*)%1$","%2"))
 end
 
---~ function string:unquote()
---~     if find(self,"^[\'\"]") then
---~         return sub(self,2,-2)
+--~ function stringunquoted(str)
+--~     if find(str,"^[\'\"]") then
+--~         return sub(str,2,-2)
 --~     else
---~         return self
+--~         return str
 --~     end
 --~ end
 
-function string:quote() -- we could use format("%q")
-    return format("%q",self)
+function string.quoted(str)
+    return format("%q",str) -- always "
 end
 
-function string:count(pattern) -- variant 3
+function string.count(str,pattern) -- variant 3
     local n = 0
-    for _ in gmatch(self,pattern) do
+    for _ in gmatch(str,pattern) do -- not for utf
         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
+function string.limit(str,n,sentinel) -- not utf proof
+    if #str > n then
+        sentinel = sentinel or "..."
+        return sub(str,1,(n-#sentinel)) .. sentinel
     else
-        return self
+        return str
     end
 end
 
---~ function string:strip() -- the .- is quite efficient
---~  -- return match(self,"^%s*(.-)%s*$") or ""
---~  -- return match(self,'^%s*(.*%S)') or '' -- posted on lua list
---~     return find(s,'^%s*$') and '' or match(s,'^%s*(.*%S)')
---~ end
-
-do -- roberto's variant:
-    local space    = lpeg.S(" \t\v\n")
-    local nospace  = 1 - space
-    local stripper = space^0 * lpeg.C((space^0 * nospace^1)^0)
-    function string.strip(str)
-        return lpegmatch(stripper,str) or ""
-    end
-end
+local space    = S(" \t\v\n")
+local nospace  = 1 - space
+local stripper = space^0 * C((space^0 * nospace^1)^0) -- roberto's code
 
-function string:is_empty()
-    return not find(self,"%S")
+function string.strip(str)
+    return lpegmatch(stripper,str) or ""
 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, sub(str,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(sub(str,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 .. rep(chr or " ",m)
-    else
-        return self
-    end
-end
-
-function string:lpadd(n,chr)
-    local m = n-#self
-    if m > 0 then
-        return 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
+function string.is_empty(str)
+    return not find(str,"%S")
 end
 
 local patterns_escapes = {
-    ["-"] = "%-",
-    ["."] = "%.",
-    ["+"] = "%+",
-    ["*"] = "%*",
     ["%"] = "%%",
-    ["("] = "%)",
-    [")"] = "%)",
-    ["["] = "%[",
-    ["]"] = "%]",
+    ["."] = "%.",
+    ["+"] = "%+", ["-"] = "%-", ["*"] = "%*",
+    ["["] = "%[", ["]"] = "%]",
+    ["("] = "%(", [")"] = "%)",
+ -- ["{"] = "%{", ["}"] = "%}"
+ -- ["^"] = "%^", ["$"] = "%$",
 }
 
-function string:pattesc()
-    return (gsub(self,".",patterns_escapes))
-end
-
 local simple_escapes = {
     ["-"] = "%-",
     ["."] = "%.",
@@ -212,77 +92,44 @@ local simple_escapes = {
     ["*"] = ".*",
 }
 
-function string:simpleesc()
-    return (gsub(self,".",simple_escapes))
+function string.escapedpattern(str,simple)
+    return (gsub(str,".",simple and simple_escapes or patterns_escapes))
 end
 
-function string:tohash()
-    local t = { }
-    for s in gmatch(self,"([^, ]+)") do -- lpeg
-        t[s] = true
+function string.topattern(str,lowercase,strict)
+    if str == "" then
+        return ".*"
+    else
+        str = gsub(str,".",simple_escapes)
+        if lowercase then
+            str = lower(str)
+        end
+        if strict then
+            return "^" .. str .. "$"
+        else
+            return str
+        end
     end
-    return t
 end
 
-local pattern = lpeg.Ct(lpeg.C(1)^0)
 
-function string:totable()
-    return lpegmatch(pattern,self)
+function string.valid(str,default)
+    return (type(str) == "string" and str ~= "" and str) or default or nil
 end
 
---~ local t = {
---~     "1234567123456712345671234567",
---~     "a\tb\tc",
---~     "aa\tbb\tcc",
---~     "aaa\tbbb\tccc",
---~     "aaaa\tbbbb\tcccc",
---~     "aaaaa\tbbbbb\tccccc",
---~     "aaaaaa\tbbbbbb\tcccccc",
---~ }
---~ for k,v do
---~     print(string.tabtospace(t[k]))
---~ end
+-- obsolete names:
 
-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
+string.quote   = string.quoted
+string.unquote = string.unquoted
 
-function string:compactlong() -- strips newlines and leading spaces
-    self = gsub(self,"[\n\r]+ *","")
-    self = gsub(self,"^ *","")
-    return self
-end
+-- handy fallback
 
-function string:striplong() -- strips newlines and leading spaces
-    self = gsub(self,"^%s*","")
-    self = gsub(self,"[\n\r]+ *","\n")
-    return self
-end
+string.itself  = function(s) return s end
 
-function string:topattern(lowercase,strict)
-    if lowercase then
-        self = lower(self)
-    end
-    self = gsub(self,".",simple_escapes)
-    if self == "" then
-        self = ".*"
-    elseif strict then
-        self = "^" .. self .. "$"
-    end
-    return self
+-- also handy (see utf variant)
+
+local pattern = Ct(C(1)^0)
+
+function string.totable(str)
+    return lpegmatch(pattern,str)
 end