Exported variables predefinition: replace prepare system with generic resume system

anselme/ast/Anchor.lua

@@ -1,16 +1,13 @@
 local ast = require("anselme.ast")
 
-local resume_manager
-
 local Anchor
-Anchor = ast.abstract.Node {
+Anchor = ast.abstract.ResumeTarget {
 	type = "anchor",
 
 	name = nil,
 
 	init = function(self, name)
 		self.name = name
-		self._list_anchors_cache = { [name] = true }
 	end,
 
 	_hash = function(self)
@@ -20,16 +17,8 @@ Anchor = ast.abstract.Node {
 	_format = function(self, ...)
 		return "#"..self.name
 	end,
-
-	_eval = function(self, state)
-		if self:contains_resume_target(state) then
-			resume_manager:set_reached(state)
-		end
-		return Anchor:new(self.name)
-	end
 }
 
 package.loaded[...] = Anchor
-resume_manager = require("anselme.state.resume_manager")
 
 return Anchor

anselme/ast/Block.lua

@@ -36,17 +36,18 @@ local Block = ast.abstract.Node {
 	_eval = function(self, state)
 		local r
 		state.scope:push()
-		if self:contains_resume_target(state) then
+		if self:contains_current_resume_target(state) then
-			local anchor = resume_manager:get(state)
+			local target = resume_manager:get(state)
+			local no_continue = resume_manager:no_continue(state)
 			local resumed = false
 			for _, e in ipairs(self.expressions) do
-				if e:contains_anchor(anchor) then resumed = true end
+				if e:contains_resume_target(target) then resumed = true end
 				if resumed then
 					r = e:eval(state)
 					if AutoCall:issub(r) then
 						r = r:call(state, ArgumentTuple:new())
 					end
-					if Return:is(r) then
+					if Return:is(r) or no_continue then
 						break -- pass on to parent block until we reach a function boundary
 					end
 				end
@@ -65,14 +66,6 @@ local Block = ast.abstract.Node {
 		state.scope:pop()
 		return r or Nil:new()
 	end,
-
-	_prepare = function(self, state)
-		state.scope:push()
-		for _, e in ipairs(self.expressions) do
-			e:prepare(state)
-		end
-		state.scope:pop()
-	end
 }
 
 package.loaded[...] = Block

anselme/ast/Closure.lua

@@ -4,6 +4,8 @@ local ast = require("anselme.ast")
 local Overloadable, Runtime = ast.abstract.Overloadable, ast.abstract.Runtime
 local Definition
 
+local resume_manager
+
 local Closure
 Closure = Runtime(Overloadable) {
 	type = "closure",
@@ -21,8 +23,14 @@ Closure = Runtime(Overloadable) {
 		self.exported_scope = state.scope:capture()
 
 		-- pre-define exports
-		for sym, exp in pairs(self.func.exports) do
+		for _, target in pairs(self:list_resume_targets()) do
-			Definition:new(sym, exp):eval(state)
+			if Definition:is(target) and target.symbol.exported then
+				resume_manager:push_no_continue(state, target)
+				state.scope:push() -- create temp func scope, in case non-export definitions are done in the resume
+				self.func.expression:eval(state)
+				state.scope:pop()
+				resume_manager:pop(state)
+			end
 		end
 
 		state.scope:pop()
@@ -54,5 +62,6 @@ Closure = Runtime(Overloadable) {
 
 package.loaded[...] = Closure
 Definition = ast.Definition
+resume_manager = require("anselme.state.resume_manager")
 
 return Closure

anselme/ast/Definition.lua

@@ -3,7 +3,7 @@ local Nil, Overloadable
 
 local operator_priority = require("anselme.common").operator_priority
 
-local Definition = ast.abstract.Node {
+local Definition = ast.abstract.ResumeTarget {
 	type = "definition",
 
 	symbol = nil,
@@ -46,17 +46,6 @@ local Definition = ast.abstract.Node {
 
 		return Nil:new()
 	end,
-
-	_prepare = function(self, state)
-		local symbol, val = self.symbol, self.expression
-		symbol:prepare(state)
-		val:prepare(state)
-
-		-- predefine exported variables
-		if symbol.exported then
-			self:eval(state)
-		end
-	end
 }
 
 package.loaded[...] = Definition

anselme/ast/Function.lua

@@ -13,8 +13,6 @@ Function = Overloadable {
 	parameters = nil, -- ParameterTuple
 	expression = nil,
 
-	exports = nil, -- { [sym] = exp, ... }, exctracted from expression during :prepare
-
 	init = function(self, parameters, expression, exports)
 		self.parameters = parameters
 		self.expression = ReturnBoundary:new(expression)
@@ -55,7 +53,8 @@ Function = Overloadable {
 
 		state.scope:pop()
 
-		-- reminder: don't do any additionnal processing here as that won't be executed when resuming self.expression
+		-- reminder: don't do any additionnal processing here as that won't be executed when resuming self.expression directly
+		-- which is done in a few places, notably to predefine exports in Closure
 		-- instead wrap it in some additional node, like our friend ReturnBoundary
 
 		return exp
@@ -64,18 +63,6 @@ Function = Overloadable {
 	_eval = function(self, state)
 		return Closure:new(Function:new(self.parameters:eval(state), self.expression, self.exports), state)
 	end,
-
-	_prepare = function(self, state)
-		state.scope:push_export() -- recreate scope context that will be created by closure
-
-		state.scope:push()
-		self.parameters:prepare(state)
-		self.expression:prepare(state)
-		state.scope:pop()
-
-		self.exports = state.scope:capture():list_exported(state)
-		state.scope:pop()
-	end,
 }
 
 package.loaded[...] = Function

anselme/ast/Identifier.lua

@@ -29,12 +29,6 @@ Identifier = ast.abstract.Node {
 	to_symbol = function(self, modifiers)
 		return Symbol:new(self.name, modifiers)
 	end,
-
-	_prepare = function(self, state)
-		if state.scope:defined(self) then
-			state.scope:get(self):prepare(state)
-		end
-	end
 }
 
 package.loaded[...] = Identifier

anselme/ast/PartialScope.lua

@@ -56,13 +56,6 @@ PartialScope = ast.abstract.Node {
 		return exp
 	end,
 
-	_prepare = function(self, state)
-		state.scope:push_partial(unpack(self._identifiers))
-		for sym, val in pairs(self.definitions) do state.scope:define(sym, val) end
-		self.expression:prepare(state)
-		state.scope:pop()
-	end,
-
 	-- class method: if the identifier is currently defined, wrap node in an PartialScope so the identifier is still defined in this node
 	-- used to e.g. preserve the defined _ block without the need to build a full closure
 	-- used e.g. for -> translation, as we want to preserve _ while still executing the translation in the Translatable scope and not restore a different scope from a closure

anselme/ast/abstract/Node.lua

@@ -13,7 +13,7 @@ local utf8 = utf8 or require("lua-utf8")
 
 local uuid = require("anselme.common").uuid
 
-local State, Runtime, Call, Identifier, ArgumentTuple
+local Call, Identifier, ArgumentTuple
 local resume_manager
 
 local custom_call_identifier
@@ -37,9 +37,6 @@ traverse = {
 	set_source = function(self, source)
 		self:set_source(source)
 	end,
-	prepare = function(self, state)
-		self:prepare(state)
-	end,
 	merge = function(self, state, cache)
 		self:merge(state, cache)
 	end,
@@ -48,6 +45,11 @@ traverse = {
 	end,
 	list_translatable = function(self, t)
 		self:list_translatable(t)
+	end,
+	list_resume_targets = function(self, add_to_node)
+		for hash, target in pairs(self:list_resume_targets()) do
+			add_to_node._list_resume_targets_cache[hash] = target
+		end
 	end
 }
 
@@ -100,52 +102,29 @@ Node = class {
 		return self
 	end,
 
-	-- prepare the AST after parsing and before evaluation
+	-- returns a reversed list { [target hash] = true, ... } of the resume targets contained in this node and its children
-	-- this behave like a cached :traverse through the AST, except this keeps track of the scope stack and preserve evaluation order
+	-- this is cached, redefine _list_resume_targets if needed, not this function
-	-- i.e. when :prepare is called on a node, it should be in a similar scope stack context and order as will be when it will be evaluated
+	list_resume_targets = function(self)
-	-- used to predefine exported variables and other compile-time variable handling
+		if not self._list_resume_targets_cache then
-	-- note: the state here is a temporary state only used during the prepare step
+			self._list_resume_targets_cache = {}
-	-- the actual preparation is done in _prepare
+			self:_list_resume_targets()
-	-- (this can mutate the node as needed and is automatically called after each parse)
-	prepare = function(self, state)
-		assert(not Runtime:issub(self), ("can't prepare a %s node that should only exist at runtime"):format(self.type))
-		state = state or State:new()
-		if self._prepared then return end
-		local s, r = pcall(self._prepare, self, state)
-		if s then
-			self._prepared = true
-		else
-			error(format_error(state, self, r), 0)
 		end
+		return self._list_resume_targets_cache
 	end,
-	_prepared = false, -- indicate that the node was prepared and :prepare should nop
+	_list_resume_targets_cache = nil, -- list resume target cache { [target hash] = target, ... }
-	-- prepare this node. can mutate the node (considered to be part of construction).
+	-- add resume targets to _list_resume_targets_cache
-	_prepare = function(self, state)
+	_list_resume_targets = function(self)
-		self:traverse(traverse.prepare, state)
+		self:traverse(traverse.list_resume_targets, self)
 	end,
 
-	-- returns a reversed list { [anchor] = true, ... } of the anchors contained in this node and its children
+	-- returns true if the node or its children contains the resume target
-	_list_anchors = function(self)
+	contains_resume_target = function(self, target)
-		if not self._list_anchors_cache then
+		return not not self:list_resume_targets()[target:hash()]
-			self._list_anchors_cache = {}
-			self:traverse(function(v)
-				for name in pairs(v:_list_anchors()) do
-					self._list_anchors_cache[name] = true
-				end
-			end)
-		end
-		return self._list_anchors_cache
-	end,
-	_list_anchors_cache = nil,
-
-	-- returns true if the node or its children contains the anchor
-	contains_anchor = function(self, anchor)
-		return not not self:_list_anchors()[anchor.name]
 	end,
 
-	-- returns true if we are currently trying to resume to an anchor target contained in the current node
+	-- returns true if we are currently trying to resume to a resume target contained in the current node
-	contains_resume_target = function(self, state)
+	contains_current_resume_target = function(self, state)
-		return resume_manager:resuming(state) and self:contains_anchor(resume_manager:get(state))
+		return resume_manager:resuming(state) and self:contains_resume_target(resume_manager:get(state))
 	end,
 
 	-- generate a list of translatable nodes that appear in this node
@@ -332,10 +311,9 @@ Node = class {
 	-- Thus, any require here that may require other Nodes shall be done here. This method is called in anselme.lua after everything else is required.
 	_i_hate_cycles = function(self)
 		local ast = require("anselme.ast")
-		Runtime, Call, Identifier, ArgumentTuple = ast.abstract.Runtime, ast.Call, ast.Identifier, ast.ArgumentTuple
+		Call, Identifier, ArgumentTuple = ast.Call, ast.Identifier, ast.ArgumentTuple
 		custom_call_identifier = Identifier:new("_!")
 
-		State = require("anselme.state.State")
 		resume_manager = require("anselme.state.resume_manager")
 	end,
 

anselme/ast/abstract/ResumeTarget.lua

@@ -0,0 +1,27 @@
+-- nodes that can be resumed to
+
+local ast = require("anselme.ast")
+local Node = ast.abstract.Node
+
+local resume_manager
+
+local ResumeTarget = Node {
+	type = "resume target",
+	init = false,
+
+	_list_resume_targets = function(self)
+		self._list_resume_targets_cache[self:hash()] = self
+	end,
+
+	eval = function(self, state)
+		if self:contains_current_resume_target(state) then
+			resume_manager:set_reached(state)
+		end
+		return Node.eval(self, state)
+	end
+}
+
+package.loaded[...] = ResumeTarget
+resume_manager = require("anselme.state.resume_manager")
+
+return ResumeTarget

anselme/ast/abstract/Runtime.lua

@@ -1,5 +1,5 @@
 -- indicate a Runtime node: it should not exist in the AST generated by the parser but only as a result of an evaluation or call
--- is assumed to be already evaluated and prepared (will actually error on prepare)
+-- is assumed to be already evaluated; we reserve the right to error if a Runtime node occurs in something that was never evaluated
 
 local ast = require("anselme.ast")
 
@@ -8,5 +8,4 @@ return ast.abstract.Node {
 	init = false,
 
 	_evaluated = true,
-	_prepared = true
 }

anselme/parser/expression/primary/function_definition.lua

@@ -158,7 +158,7 @@ end
 
 return primary {
 	match = function(self, str)
-		return str:match("^%::?[&@]?%$")
+		return str:match("^%::?&?@?%$")
 	end,
 
 	parse = function(self, source, str, limit_pattern)

anselme/parser/expression/primary/symbol.lua

@@ -8,8 +8,8 @@ local Nil = ast.Nil
 
 return primary {
 	match = function(self, str)
-		if str:match("^%::?[&@]?") then
+		if str:match("^%::?&?@?") then
-			return identifier:match(str:match("^%::?[&@]?(.-)$"))
+			return identifier:match(str:match("^%::?&?@?(.-)$"))
 		end
 		return false
 	end,

anselme/parser/init.lua

@@ -7,7 +7,5 @@ return function(code, source)
 	local tree = code_to_tree(code, source)
 	local block = tree_to_ast(tree)
 
-	block:prepare()
-
 	return block
 end

anselme/state/resume_manager.lua

@@ -1,44 +1,64 @@
 local class = require("anselme.lib.class")
 
 local ast = require("anselme.ast")
-local Nil, Identifier, Anchor
+local Nil, Identifier, ResumeTarget, Boolean
 
 -- stack of resumable contexts
-local resume_anchor_identifier, resume_anchor_symbol
+local resume_target_identifier, resume_target_symbol, resume_no_continue_identifier, resume_no_continue_symbol
 
 local resume_manager = class {
 	init = false,
 
-	-- push a new resume context: all run code between this and the next push will try to resume to anchor
+	-- push a new resume context: all run code between this and the next push will try to resume to target
-	push = function(self, state, anchor)
+	push = function(self, state, target)
-		assert(Anchor:is(anchor), "can only resume to an anchor target") -- well technically it wouldn't be hard to allow to resume to any node, but I feel like there's already enough stuff in Anselme that was done just because it could be done
+		assert(ResumeTarget:issub(target), "can only resume to a resume target")
-		state.scope:push_partial(resume_anchor_identifier)
+		state.scope:push_partial(resume_target_identifier, resume_no_continue_identifier)
-		state.scope:define(resume_anchor_symbol, anchor)
+		state.scope:define(resume_target_symbol, target)
+		state.scope:define(resume_no_continue_symbol, Boolean:new(false))
+	end,
+	-- same as :push, but the resume will stop immediately after reaching the target or a node containing the target
+	-- (we will stop even if the node is not directly reached - this is used to run a specific line containing a node,
+	-- notably for Definition of exported variables)
+	push_no_continue = function(self, state, target)
+		assert(ResumeTarget:issub(target), "can only resume to a resume target")
+		state.scope:push_partial(resume_target_identifier, resume_no_continue_identifier)
+		state.scope:define(resume_target_symbol, target)
+		state.scope:define(resume_no_continue_symbol, Boolean:new(true))
 	end,
 	-- pop the current resume context
 	pop = function(self, state)
 		state.scope:pop()
 	end,
 
-	-- returns true if we are currently trying to resume to an anchor
+	-- returns true if we are currently trying to resume to a target
 	resuming = function(self, state)
-		return state.scope:defined(resume_anchor_identifier) and not Nil:is(state.scope:get(resume_anchor_identifier))
+		return state.scope:defined(resume_target_identifier) and not Nil:is(state.scope:get(resume_target_identifier))
 	end,
-	-- returns the anchor we are trying to resume to
+	-- returns the target we are trying to resume to
+	-- (assumes that we are currently :resuming)
 	get = function(self, state)
-		return state.scope:get(resume_anchor_identifier)
+		return state.scope:get(resume_target_identifier)
 	end,
-	-- mark the anchor as reached and stop the resume
+	-- mark the target as reached and stop the resume
+	-- (assumes that we are currently :resuming)
 	set_reached = function(self, state)
-		state.scope:set(resume_anchor_identifier, Nil:new())
+		state.scope:set(resume_target_identifier, Nil:new())
 	end,
+	-- indicate if the evaluation should stop after reaching a node containing the target
+	-- (assumes that we are currently :resuming)
+	no_continue = function(self, state)
+		return state.scope:get(resume_no_continue_identifier):to_lua(state)
+	end
 }
 
 package.loaded[...] = resume_manager
 
-Nil, Identifier, Anchor = ast.Nil, ast.Identifier, ast.Anchor
+Nil, Identifier, ResumeTarget, Boolean = ast.Nil, ast.Identifier, ast.abstract.ResumeTarget, ast.Boolean
 
-resume_anchor_identifier = Identifier:new("_resume_anchor")
+resume_target_identifier = Identifier:new("_resume_target")
-resume_anchor_symbol = resume_anchor_identifier:to_symbol()
+resume_target_symbol = resume_target_identifier:to_symbol()
+
+resume_no_continue_identifier = Identifier:new("_resume_no_continue")
+resume_no_continue_symbol = resume_no_continue_identifier:to_symbol()
 
 return resume_manager

anselme/stdlib/text.lua

@@ -19,7 +19,7 @@ return {
 	{
 		"_|>_", "(txt::text, fn)",
 		function(state, text, func)
-			if func:contains_resume_target(state) then
+			if func:contains_current_resume_target(state) then
 				func:call(state, ArgumentTuple:new())
 				event_manager:write_and_discard_on_flush(state, Choice:new(text, func))
 			else

test/results/exported variable nested.ans

@@ -0,0 +1,11 @@
+--# run #--
+--- text ---
+| {}"" {}"42" {}"" |
+--- error ---
+./anselme/stdlib/closure.lua:15: no exported variable "y" defined in closure
+	↳ from test/tests/exported variable nested.ans:10:4 in call: f . "y"
+	↳ from test/tests/exported variable nested.ans:10:1 in text interpolation: | {f . "y"} |
+	↳ from test/tests/exported variable nested.ans:10:1 in translatable: | {f . "y"} |
+	↳ from ? in block: :f = ($() _)…
+--# saved #--
+{}

test/results/symbol alias exported.ans

@@ -0,0 +1,11 @@
+--# run #--
+--- text ---
+| {}"c=" {}"2" {}" (2)" |
+| {}"l=" {}"*[1, 2, 3]" {}" (*[1,2,3])" |
+--- text ---
+| {}"c=" {}"5" {}" (5)" |
+| {}"l=" {}"*[1, 5, 3]" {}" (*[1,5,3])" |
+--- return ---
+()
+--# saved #--
+{}

test/tests/exported variable nested.ans

@@ -0,0 +1,10 @@
+:f = $
+	| kk
+	:@x = 42
+	:y = $
+		:@z = 12
+	| ko
+
+|{f.x}
+
+|{f.y}

test/tests/symbol alias exported.ans

@@ -0,0 +1,11 @@
+:@l = *[1,2,3]
+
+:&@c = l(2)
+
+| c={c} (2)
+| l={l} (*[1,2,3])
+
+c = 5
+
+| c={c} (5)
+| l={l} (*[1,5,3])