1 files changed, 118 insertions, 2 deletions
diff --git a/tex/context/base/util-tab.lua b/tex/context/base/util-tab.lua
index 28a6b8cc5..7a2da298e 100644
--- a/tex/context/base/util-tab.lua
+++ b/tex/context/base/util-tab.lua
@@ -10,10 +10,11 @@ utilities        = utilities or {}
 utilities.tables = utilities.tables or { }
 local tables     = utilities.tables
 
-local format, gmatch, rep = string.format, string.gmatch, string.rep
+local format, gmatch, rep, gsub = string.format, string.gmatch, string.rep, string.gsub
 local concat, insert, remove = table.concat, table.insert, table.remove
 local setmetatable, getmetatable, tonumber, tostring = setmetatable, getmetatable, tonumber, tostring
-local type, next, rawset, tonumber = type, next, rawset, tonumber
+local type, next, rawset, tonumber, loadstring = type, next, rawset, tonumber, loadstring
+local lpegmatch, P, Cs = lpeg.match, lpeg.P, lpeg.Cs
 
 function tables.definetable(target) -- defines undefined tables
     local composed, t, n = nil, { }, 0
@@ -166,3 +167,118 @@ function tables.encapsulate(core,capsule,protect)
         } )
     end
 end
+
+local function serialize(t,r,outer) -- no mixes
+    r[#r+1] = "{"
+    local n = #t
+    if n > 0 then
+        for i=1,n do
+            local v = t[i]
+            local tv = type(v)
+            if tv == "string" then
+                r[#r+1] = format("%q,",v)
+            elseif tv == "number" then
+                r[#r+1] = format("%s,",v)
+            elseif tv == "table" then
+                serialize(v,r)
+            elseif tv == "boolean" then
+                r[#r+1] = format("%s,",tostring(v))
+            end
+        end
+    else
+        for k, v in next, t do
+            local tv = type(v)
+            if tv == "string" then
+                r[#r+1] = format("[%q]=%q,",k,v)
+            elseif tv == "number" then
+                r[#r+1] = format("[%q]=%s,",k,v)
+            elseif tv == "table" then
+                r[#r+1] = format("[%q]=",k)
+                serialize(v,r)
+            elseif tv == "boolean" then
+                r[#r+1] = format("[%q]=%s,",k,tostring(v))
+            end
+        end
+    end
+    if outer then
+        r[#r+1] = "}"
+    else
+        r[#r+1] = "},"
+    end
+    return r
+end
+
+function table.fastserialize(t,prefix)
+    return concat(serialize(t,{ prefix or "return" },true))
+end
+
+function table.deserialize(str)
+    if not str or str == "" then
+        return
+    end
+    local code = loadstring(str)
+    if not code then
+        return
+    end
+    code = code()
+    if not code then
+        return
+    end
+    return code
+end
+
+-- inspect(table.fastserialize { a = 1, b = { 4, { 5, 6 } }, c = { d = 7, e = 'f"g\nh' } })
+
+function table.load(filename)
+    if filename then
+        local t = io.loaddata(filename)
+        if t and t ~= "" then
+            t = loadstring(t)
+            if type(t) == "function" then
+                t = t()
+                if type(t) == "table" then
+                    return t
+                end
+            end
+        end
+    end
+end
+
+local function slowdrop(t)
+    local r = { }
+    local l = { }
+    for i=1,#t do
+        local ti = t[i]
+        local j = 0
+        for k, v in next, ti do
+            j = j + 1
+            l[j] = format("%s=%q",k,v)
+        end
+        r[i] = format(" {%s},\n",concat(l))
+    end
+    return format("return {\n%s}",concat(r))
+end
+
+local function fastdrop(t)
+    local r = { "return {\n" }
+    for i=1,#t do
+        local ti = t[i]
+        r[#r+1] = " {"
+        for k, v in next, ti do
+            r[#r+1] = format("%s=%q",k,v)
+        end
+        r[#r+1] = "},\n"
+    end
+    r[#r+1] = "}"
+    return concat(r)
+end
+
+function table.drop(t,slow)
+    if #t == 0 then
+        return "return { }"
+    elseif slow == true then
+        return slowdrop(t) -- less memory
+    else
+        return fastdrop(t) -- some 15% faster
+    end
+end