Added ltn12 module. Modified mime to be stand alone.

Still crashes on invalid input. Dunno why.

1 files changed, 171 insertions, 0 deletions

diff --git a/src/ltn12.lua b/src/ltn12.lua
new file mode 100644
index 0000000..548588a
--- /dev/null
+++ b/src/ltn12.lua
@@ -0,0 +1,171 @@
+-- create code namespace inside LuaSocket namespace
+ltn12 = ltn12 or {}
+-- make all module globals fall into mime namespace
+setmetatable(ltn12, { __index = _G })
+setfenv(1, ltn12)
+
+-- sub namespaces
+filter = {}
+source = {}
+sink = {}
+
+-- 2048 seems to be better in windows...
+BLOCKSIZE = 2048
+
+-- returns a high level filter that cycles a cycles a low-level filter
+function filter.cycle(low, ctx, extra)
+    return function(chunk)
+        local ret
+        ret, ctx = low(ctx, chunk, extra)
+        return ret
+    end
+end
+
+-- chains two filters together
+local function chain2(f1, f2)
+    return function(chunk)
+        local ret = f2(f1(chunk))
+        if chunk then return ret
+        else return ret .. f2() end
+    end
+end
+
+-- chains a bunch of filters together
+function filter.chain(...)
+    local f = arg[1]
+    for i = 2, table.getn(arg) do
+        f = chain2(f, arg[i])
+    end
+    return f
+end
+
+-- create an empty source
+function source.empty(err)
+    return function()
+        return nil, err
+    end
+end
+
+-- creates a file source
+function source.file(handle, io_err)
+    if handle then
+        return function()
+            local chunk = handle:read(BLOCKSIZE)
+            if not chunk then handle:close() end
+            return chunk
+        end
+    else source.empty(io_err or "unable to open file") end
+end
+
+-- turns a fancy source into a simple source
+function source.simplify(src)
+    return function()
+        local chunk, err_or_new = src()
+        src = err_or_new or src
+        if not chunk then return nil, err_or_new
+        else return chunk end
+    end
+end
+
+-- creates string source
+function source.string(s)
+    if s then
+        local i = 1
+        return function()
+            local chunk = string.sub(s, i, i+BLOCKSIZE-1)
+            i = i + BLOCKSIZE
+            if chunk ~= "" then return chunk
+            else return nil end
+        end
+    else source.empty() end
+end
+
+-- creates rewindable source
+function source.rewind(src)
+    local t = {}
+    src = source.simplify(src)
+    return function(chunk)
+        if not chunk then
+            chunk = table.remove(t)
+            if not chunk then return src()
+            else return chunk end
+        else
+            table.insert(t, chunk)
+        end
+    end
+end
+
+-- chains a source with a filter
+function source.chain(src, f)
+    src = source.simplify(src)
+    local chain = function()
+        local chunk, err = src()
+        if not chunk then return f(nil), source.empty(err)
+        else return f(chunk) end
+    end
+    return source.simplify(chain)
+end
+
+-- creates a sink that stores into a table
+function sink.table(t)
+    t = t or {}
+    local f = function(chunk, err)
+        if chunk then table.insert(t, chunk) end
+        return 1
+    end
+    return f, t
+end
+
+-- turns a fancy sink into a simple sink
+function sink.simplify(snk)
+    return function(chunk, err)
+        local ret, err_or_new = snk(chunk, err)
+        if not ret then return nil, err_or_new end
+        snk = err_or_new or snk
+        return 1
+    end
+end
+
+-- creates a file sink
+function sink.file(handle, io_err)
+    if handle then
+        return function(chunk, err)
+            if not chunk then 
+                handle:close()
+                return nil, err
+            end
+            return handle:write(chunk)
+        end
+    else sink.null() end
+end
+
+-- creates a sink that discards data
+local function null()
+    return 1
+end
+
+function sink.null()
+    return null
+end
+
+-- chains a sink with a filter 
+function sink.chain(f, snk)
+    snk = sink.simplify(snk)
+    return function(chunk, err)
+        local r, e = snk(f(chunk))
+        if not r then return nil, e end
+        if not chunk then return snk(nil, err) end
+        return 1
+    end
+end
+
+-- pumps all data from a source to a sink
+function pump(src, snk)
+    snk = sink.simplify(snk)
+    for chunk, src_err in source.simplify(src) do
+        local ret, snk_err = snk(chunk, src_err)
+        if not chunk or not ret then 
+            return not src_err and not snk_err, src_err or snk_err 
+        end
+    end
+end