2016-05-17 19:25:00

1 files changed, 213 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/l-string.lua b/tex/context/base/mkiv/l-string.lua
new file mode 100644
index 000000000..e9dc2bbbc
--- /dev/null
+++ b/tex/context/base/mkiv/l-string.lua
@@ -0,0 +1,213 @@
+if not modules then modules = { } end modules ['l-string'] = {
+    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"
+}
+
+local string = string
+local sub, gmatch, format, char, byte, rep, lower = string.sub, string.gmatch, string.format, string.char, string.byte, string.rep, string.lower
+local lpegmatch, patterns = lpeg.match, lpeg.patterns
+local P, S, C, Ct, Cc, Cs = lpeg.P, lpeg.S, lpeg.C, lpeg.Ct, lpeg.Cc, lpeg.Cs
+
+-- Some functions are already defined in l-lpeg and maybe some from here will
+-- move there (unless we also expose caches).
+
+-- if not string.split then
+--
+--     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
+--         end
+--         return t
+--     end
+--
+-- end
+
+-- function string.unquoted(str)
+--     return (gsub(str,"^([\"\'])(.*)%1$","%2")) -- interesting pattern
+-- end
+
+local unquoted = patterns.squote * C(patterns.nosquote) * patterns.squote
+               + patterns.dquote * C(patterns.nodquote) * patterns.dquote
+
+function string.unquoted(str)
+    return lpegmatch(unquoted,str) or str
+end
+
+-- print(string.unquoted("test"))
+-- print(string.unquoted([["t\"est"]]))
+-- print(string.unquoted([["t\"est"x]]))
+-- print(string.unquoted("\'test\'"))
+-- print(string.unquoted('"test"'))
+-- print(string.unquoted('"test"'))
+
+function string.quoted(str)
+    return format("%q",str) -- always double quote
+end
+
+function string.count(str,pattern) -- variant 3
+    local n = 0
+    for _ in gmatch(str,pattern) do -- not for utf
+        n = n + 1
+    end
+    return n
+end
+
+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 str
+    end
+end
+
+local stripper     = patterns.stripper
+local fullstripper = patterns.fullstripper
+local collapser    = patterns.collapser
+local longtostring = patterns.longtostring
+
+function string.strip(str)
+    return lpegmatch(stripper,str) or ""
+end
+
+function string.fullstrip(str)
+    return lpegmatch(fullstripper,str) or ""
+end
+
+function string.collapsespaces(str)
+    return lpegmatch(collapser,str) or ""
+end
+
+function string.longtostring(str)
+    return lpegmatch(longtostring,str) or ""
+end
+
+-- function string.is_empty(str)
+--     return not find(str,"%S")
+-- end
+
+local pattern = P(" ")^0 * P(-1) -- maybe also newlines
+
+-- patterns.onlyspaces = pattern
+
+function string.is_empty(str)
+    if str == "" then
+        return true
+    else
+        return lpegmatch(pattern,str) and true or false
+    end
+end
+
+-- if not string.escapedpattern then
+--
+--     local patterns_escapes = {
+--         ["%"] = "%%",
+--         ["."] = "%.",
+--         ["+"] = "%+", ["-"] = "%-", ["*"] = "%*",
+--         ["["] = "%[", ["]"] = "%]",
+--         ["("] = "%(", [")"] = "%)",
+--      -- ["{"] = "%{", ["}"] = "%}"
+--      -- ["^"] = "%^", ["$"] = "%$",
+--     }
+--
+--     local simple_escapes = {
+--         ["-"] = "%-",
+--         ["."] = "%.",
+--         ["?"] = ".",
+--         ["*"] = ".*",
+--     }
+--
+--     function string.escapedpattern(str,simple)
+--         return (gsub(str,".",simple and simple_escapes or patterns_escapes))
+--     end
+--
+--     function string.topattern(str,lowercase,strict)
+--         if str == "" then
+--             return ".*"
+--         else
+--             str = gsub(str,".",simple_escapes)
+--             if lowercase then
+--                 str = lower(str)
+--             end
+--             if strict then
+--                 return "^" .. str .. "$"
+--             else
+--                 return str
+--             end
+--         end
+--     end
+--
+-- end
+
+--- needs checking
+
+local anything     = patterns.anything
+local allescapes   = Cc("%") * S(".-+%?()[]*") -- also {} and ^$ ?
+local someescapes  = Cc("%") * S(".-+%()[]")   -- also {} and ^$ ?
+local matchescapes = Cc(".") * S("*?")         -- wildcard and single match
+
+local pattern_a = Cs ( ( allescapes + anything )^0 )
+local pattern_b = Cs ( ( someescapes + matchescapes + anything )^0 )
+local pattern_c = Cs ( Cc("^") * ( someescapes + matchescapes + anything )^0 * Cc("$") )
+
+function string.escapedpattern(str,simple)
+    return lpegmatch(simple and pattern_b or pattern_a,str)
+end
+
+function string.topattern(str,lowercase,strict)
+    if str=="" or type(str) ~= "string" then
+        return ".*"
+    elseif strict then
+        str = lpegmatch(pattern_c,str)
+    else
+        str = lpegmatch(pattern_b,str)
+    end
+    if lowercase then
+        return lower(str)
+    else
+        return str
+    end
+end
+
+-- print(string.escapedpattern("12+34*.tex",false))
+-- print(string.escapedpattern("12+34*.tex",true))
+-- print(string.topattern     ("12+34*.tex",false,false))
+-- print(string.topattern     ("12+34*.tex",false,true))
+
+function string.valid(str,default)
+    return (type(str) == "string" and str ~= "" and str) or default or nil
+end
+
+-- handy fallback
+
+string.itself  = function(s) return s end
+
+-- also handy (see utf variant)
+
+local pattern_c = Ct( C(1)      ^0) -- string and not utf !
+local pattern_b = Ct((C(1)/byte)^0)
+
+function string.totable(str,bytes)
+    return lpegmatch(bytes and pattern_b or pattern_c,str)
+end
+
+-- handy from within tex:
+
+local replacer = lpeg.replacer("@","%%") -- Watch the escaped % in lpeg!
+
+function string.tformat(fmt,...)
+    return format(lpegmatch(replacer,fmt),...)
+end
+
+-- obsolete names:
+
+string.quote   = string.quoted
+string.unquote = string.unquoted