many thingsHEADtrunk

1 files changed, 45 insertions, 0 deletions

diff --git a/config.lua b/config.lua
new file mode 100644
index 0000000..a8838c8
--- /dev/null
+++ b/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}