promise/sbrl: bugfix

it should work in most situations now.

promise.lua

@@ -1,3 +1,5 @@
+local inspect = require("worldeditadditions_core.utils.inspect")
+
 --- Javascript Promises, implemented in Lua
 -- In other words, a wrapper to manage asynchronous operations.
 -- Due to limitations of Lua, while this Promise API is similar it isn't exactly the same as in JS. Most notably is that there is a .run() function you must call AFTER you call .then_() as many times as you need.
@@ -15,92 +17,73 @@ Promise.__name = "Promise" -- A hack to allow identification in wea.inspect
 function Promise.new(fn)
 	local result = {
 		state = "pending",
-		fns = { { then_ = fn } }
+		fns = { { fn_then_ = fn } }
 	}
 	setmetatable(result, Promise)
 	
 	return result
 end
 
--- NOTE: fn_catch support is NOT FULLY IMPLEMENTED yet!
--- Example: It doesn't work when calling non-async .then()s!
-function Promise.then_(self, fn_then, fn_catch)
-	local step_item = {
-		then_ = fn_then,
-	}
-	if type(fn_catch) == "function" then
-		step_item.catch_ = fn_catch
-	end
-	
-	table.insert(self.fns, step_item)
-	
-	return self
+
+------------------------------------------------------------------------
+
+local do_unpack = unpack
+if not do_unpack then do_unpack = table.unpack end
+if not do_unpack then
+	error("Error: Failed to find unpack implementation")
 end
 
---- Executes the function this Promise is wrapping all associated chained functions in sequence.
--- This is a separate method for portability, since Lua does not implement setTimeout which is required to ensure that if an non-async function is wrapped the parent function still has time to call .then_() before it finishes and the associated .then_()ed functions are attached correctly.
--- 
--- WARNING: If you call .then_() AFTER calling .run(), your .then_()ed function may not be called correctly!
--- @returns	Promise	The current promise, for daisy chaining purposes.
-function Promise.run(self)
-	-- TODO update self.state here
-	do_run(promise, {}, 1, function(...)
-		
-	end)
-	return self
-end
-
-
-
 local function do_run(promise, args, depth, origin_resolve)
+	-- print("DO_RUN promise", inspect(promise), "args", inspect(args), "depth", depth, "origin_resolve", origin_resolve)
 	---
 	-- 0: Termination condition
 	---
 	if #promise.fns == 0 then
 		promise.state = "fulfilled"
-		origin_resolve(table.unpack(args))
+		origin_resolve(do_unpack(args))
 		return
 	end
-	
+
 	---
 	-- 1: Sort out inputs
 	---
 	if args == nil then args = {} end
 	local next = table.remove(promise.fns, 1)
-	
-	local do_next_fn = function(args)
-		do_run(promise, args, depth + 1)
+
+	local do_next_fn = function(args_to_pass)
+		do_run(promise, args_to_pass, depth + 1, origin_resolve)
 	end
-	
-	
+
+
 	---
 	-- 2: Run teh function!
 	---
-	
+
 	-- (if it's the 1st one in the sequence we treat it specially)
 	local results
 	if depth == 1 then
 		-- This function is the inner one of a promise already.
 		-- It has already recieved arguments, so it expected resolve/reject instead
-		next.then_(function(...) -- RESOLVE
+		next.fn_then_(function(...) -- RESOLVE
 			if getmetatable(arg[1]) == Promise then
 				promise.state = "rejected"
 				error("Error: Returning nested Promises is not currently supported.")
 			end
-			
-			do_next_fn(args) -- Execute the next one in the sequence
+
+			do_next_fn(arg) -- Execute the next one in the sequence
 		end, function(...) -- REJECT
 			promise.state = "rejected"
-			if type(next.catch_) == "function" then
-				next.catch_(table.unpack(arg))
+			if type(next.fn_catch_) == "function" then
+				next.fn_catch_(do_unpack(arg))
 			else
-				error("Error: Promise rejected but no catch function present. TODO make this error message more useful and informative.")
+				error(
+				"Error: Promise rejected but no catch function present. TODO make this error message more useful and informative.")
 				-- If there's no catch registered, throw an error
 			end
 		end)
 	else
-		results = { next.then_(table.unpack(args)) }
-		
+		results = { next.fn_then_(do_unpack(args)) }
+
 		---
 		-- 3: Handle the aftermath
 		---
@@ -121,35 +104,67 @@ local function do_run(promise, args, depth, origin_resolve)
 			do_next_fn(results)
 		end
 	end
+end
+
+------------------------------------------------------------------------
+
+
+-- NOTE: fn_catch support is NOT FULLY IMPLEMENTED yet!
+-- Example: It doesn't work when calling non-async .then()s!
+function Promise.then_(self, fn_then, fn_catch)
+	local step_item = {
+		fn_then_ = fn_then,
+	}
+	if type(fn_catch) == "function" then
+		step_item.fn_catch_ = fn_catch
+	end
 	
+	table.insert(self.fns, step_item)
+	
+	return self
+end
+
+--- Executes the function this Promise is wrapping all associated chained functions in sequence.
+-- This is a separate method for portability, since Lua does not implement setTimeout which is required to ensure that if an non-async function is wrapped the parent function still has time to call .then_() before it finishes and the associated .then_()ed functions are attached correctly.
+-- 
+-- WARNING: If you call .then_() AFTER calling .run(), your .then_()ed function may not be called correctly!
+-- @returns	Promise	The current promise, for daisy chaining purposes.
+function Promise.run(self)
+	-- TODO update self.state here
+	do_run(self, {}, 1, function(...)
+		
+	end)
+	return self
 end
 
 
-return Promise
+
+
+-- return Promise
 
 
 -- TEST example code, TODO test this
 
--- function test()
--- 	return Promise.new(function(resolve, reject)
--- 		-- TODO do something asyncy here
--- 		print("DEBUG running test function")
--- 		resolve(4)
--- 	end)
--- end
+function test()
+	return Promise.new(function(resolve, reject)
+		-- TODO do something asyncy here
+		print("DEBUG running test function")
+		resolve(4)
+	end)
+end
 
 
--- test()
--- 	.then_(function(val)
--- 		print("DEBUG then #1 VAL", val)
--- 		return val * 2
--- 	end)
--- 	.then_(function(val)
--- 		print("DEBUG then #2 VAL", val)
--- 		return math.sqrt(val)
--- 	end)
--- 	.then_(function(val)
--- 		print("DEBUG then #3 VAL", val)
--- 	end)
--- 	.run()
+test()
+	:then_(function(val)
+		print("DEBUG then #1 VAL", val)
+		return val * 2
+	end)
+	:then_(function(val)
+		print("DEBUG then #2 VAL", val)
+		return math.sqrt(val)
+	end)
+	:then_(function(val)
+		print("DEBUG then #3 VAL", val)
+	end)
+	:run()