the Restructuring

3 files changed, 99 insertions, 0 deletions

diff --git a/util/channel.lua b/util/channel.lua
new file mode 100644
index 0000000..e908069
--- /dev/null
+++ b/util/channel.lua
@@ -0,0 +1,15 @@
+-- channel descriptor
+
+local Channel = {}
+function Channel.make(pylon, descriptor)
+	return setmetatable({pylon=pylon, descriptor=descriptor}, Channel)
+end
+function Channel.__eq(self, other)
+	return self.pylon == other.pylon and self.descriptor == other.descriptor
+end
+function Channel.__call(_, ...) return Channel.make(...) end
+function Channel.__tostring(self)
+	return self.pylon.name .. ':' .. self.descriptor
+end
+setmetatable(Channel, Channel)
+return Channel
diff --git a/util/config.lua b/util/config.lua
new file mode 100644
index 0000000..c19a087
--- /dev/null
+++ b/util/config.lua
@@ -0,0 +1,45 @@
+local function partial(f,x) return function(...) return f(x,...) end end
+
+local function kv_syntax(block,line)
+	local k,v = line:match"^([a-z0-9_-]+)%s*=%s*(.*)$"
+	assert(k,"syntax error in kv line: "..line)
+	k = k:gsub("-","_")
+	block[k]=v
+end
+
+local function tuple_syntax(pattern) return function(block,line)
+	local matches = {line:match(pattern)}
+	assert(matches[1], "syntax error in tuple line: "..line)
+	table.insert(block, matches)
+end end 
+
+local schema = {
+	pylon = kv_syntax,
+	bus = tuple_syntax"^(%S+)%s+(%S+)$",
+}
+
+local function parse_file(file)
+	local blocks = {}
+	for k in pairs(schema) do blocks[k] = {} end
+	local line_handler = function() error("line outside of block") end
+
+	for line in file:lines() do
+		line = line:gsub(";.*$",""):gsub("^%s*",""):gsub("%s*$","")
+		if line == '' then goto next end
+
+		local block_type, block_name = line:match"%[%s*(%S+)%s+(%S+)%s*%]"
+		if block_type then
+			local blocks_of_this_type = assert(blocks[block_type],"no such block type "..block_type)
+			local block = {}
+			blocks_of_this_type[block_name] = block
+			line_handler = partial(schema[block_type], block)
+		else
+			line_handler(line)
+		end
+		::next::
+	end
+
+	return blocks
+end
+
+return {parse=parse_file}
diff --git a/util/queue.lua b/util/queue.lua
new file mode 100644
index 0000000..8c9c373
--- /dev/null
+++ b/util/queue.lua
@@ -0,0 +1,39 @@
+local cqueues = require'cqueues'
+local condition = require'cqueues.condition'
+local cqaux = require'cqueues.auxlib'
+
+local Queue = {}
+
+function Queue.make()
+	return setmetatable({
+		items = {},
+		cv = condition.new(),
+	}, {__index=Queue})
+end
+
+function Queue.enqueue(self, ...)
+	local item = table.pack(...)
+	table.insert(self.items, item)
+	if #self.items > 128 then
+		print('warning: queue is quite big')
+	end
+	self.cv:signal()
+end
+
+function Queue.iter(self)
+	return cqaux.wrap(function()
+		while true do
+			while #self.items > 0 do
+				local items = self.items
+				self.items = {} -- the old switcheroo
+				for _, item in ipairs(items) do
+					coroutine.yield(table.unpack(item, 1, item.n))
+				end
+			end
+			self.cv:wait()
+		end
+	end)
+end
+
+
+return Queue