diff --git a/anselme/ast/Typed.lua b/anselme/ast/Typed.lua
index 4652641..1ea7c72 100644
--- a/anselme/ast/Typed.lua
+++ b/anselme/ast/Typed.lua
@@ -28,7 +28,7 @@ Typed = ast.abstract.Runtime {
 				return custom_format:call(state, d_args):format(state, prio, ...)
 			end
 		end
-		return ("type(%s, %s)"):format(self.type_expression:format(state, operator_priority["_,_"], ...), self.expression:format_right(state, operator_priority["_,_"], ...))
+		return ("type(%s, %s)"):format(self.expression:format(state, operator_priority["_,_"], ...), self.type_expression:format_right(state, operator_priority["_,_"], ...))
 	end,
 
 	traverse = function(self, fn, ...)
diff --git a/anselme/stdlib/attached block.lua b/anselme/stdlib/attached block.lua
index fa4babf..73cbc12 100644
--- a/anselme/stdlib/attached block.lua	
+++ b/anselme/stdlib/attached block.lua	
@@ -11,12 +11,17 @@ return {
 		function(state, level, keep_return)
 			-- level 2: env of the function that called the function that called attached block
 			local env = calling_environment_manager:get_level(state, level:to_lua(state)+1)
-			local r = env:get(state, block_identifier)
+			local block = env:get(state, block_identifier).expression
+			local fn
 			if keep_return:truthy() then
-				return Function:new(ParameterTuple:new(), r.expression):eval(state)
+				fn = Function:new(ParameterTuple:new(), block)
 			else
-				return Function:with_return_boundary(ParameterTuple:new(), r.expression):eval(state)
+				fn = Function:with_return_boundary(ParameterTuple:new(), block)
 			end
+			state.scope:push(env)
+			fn = fn:eval(state) -- make closure
+			state.scope:pop()
+			return fn
 		end
 	},
 	{
@@ -25,12 +30,17 @@ return {
 			-- level 2: env of the function that called the function that called attached block
 			local env = calling_environment_manager:get_level(state, level:to_lua(state)+1)
 			if env:defined(state, block_identifier) then
-				local r = env:get(state, block_identifier)
+				local block = env:get(state, block_identifier).expression
+				local fn
 				if keep_return:truthy() then
-					return Function:new(ParameterTuple:new(), r.expression):eval(state)
+					fn = Function:new(ParameterTuple:new(), block)
 				else
-					return Function:with_return_boundary(ParameterTuple:new(), r.expression):eval(state)
+					fn = Function:with_return_boundary(ParameterTuple:new(), block)
 				end
+				state.scope:push(env)
+				fn = fn:eval(state) -- make closure
+				state.scope:pop()
+				return fn
 			else
 				return default
 			end
diff --git a/anselme/stdlib/for.lua b/anselme/stdlib/for.lua
new file mode 100644
index 0000000..bd782fc
--- /dev/null
+++ b/anselme/stdlib/for.lua
@@ -0,0 +1,50 @@
+return [[
+/* For loop */
+:@$for(symbol::symbol, var, block=attached block(keep return=true))
+	:iterator = iter(var)
+	:value = iterator()
+	:name = symbol!to string
+	block.(symbol) = value
+	while($value != ())
+		:r = block!
+		value = iterator()
+		block.(name) = value
+		r
+
+/* Range iterables */
+:@$range(stop)
+	[1, stop, 1]!type("range")
+:@$range(start, stop, step=1)
+	[start, stop, step]!type("range")
+:@$iter(range::is("range"))
+	:v = range!value
+	:start = v(1)
+	:stop = v(2)
+	:step = v(3)
+	:i = start
+	if(step > 0)
+		return($_)
+			if(i <= stop)
+				i += step
+				return(i-step)
+	else!
+		return($_)
+			if(i >= stop)
+				i += step
+				return(i-step)
+
+/* List/tuple iterables */
+:tuple or list = $(x) x!type == "tuple" | x!type == "list"
+:@$iter(tuple::tuple or list)
+	:n = tuple!len
+	:i = 0
+	$
+		if(i < n)
+			i += 1
+			return(tuple(i))
+
+/* Table */
+:@$iter(table::table)
+	:s = table!to struct
+	iter(s)
+]]
diff --git a/anselme/stdlib/init.lua b/anselme/stdlib/init.lua
index cf8f700..0f65395 100644
--- a/anselme/stdlib/init.lua
+++ b/anselme/stdlib/init.lua
@@ -26,6 +26,7 @@ return function(main_state)
 		"boot",
 		"number",
 		"string",
+		"symbol",
 		"text",
 		"pair",
 		"structures",
@@ -34,6 +35,7 @@ return function(main_state)
 		"function",
 		"resume",
 		"persist",
+		"for",
 		"script"
 	})
 end
diff --git a/anselme/stdlib/structures.lua b/anselme/stdlib/structures.lua
index d8ccab2..a104d1b 100644
--- a/anselme/stdlib/structures.lua
+++ b/anselme/stdlib/structures.lua
@@ -1,5 +1,5 @@
 local ast = require("anselme.ast")
-local Nil, List, Table, Number = ast.Nil, ast.List, ast.Table, ast.Number
+local Nil, List, Table, Number, LuaFunction, ParameterTuple, Boolean = ast.Nil, ast.List, ast.Table, ast.Number, ast.LuaFunction, ast.ParameterTuple, ast.Boolean
 
 return {
 	-- tuple
@@ -112,6 +112,23 @@ return {
 			return s:get(k)
 		end
 	},
+	{
+		"has", "(s::struct, key)",
+		function(state, s, k)
+			return Boolean:new(s:has(k))
+		end
+	},
+	{
+		"iter", "(s::struct)",
+		function(state, struct)
+			local iter = struct:iter()
+			return LuaFunction:new(ParameterTuple:new(), function()
+				local k = iter()
+				if k == nil then return Nil:new()
+				else return k end
+			end)
+		end
+	},
 
 	-- table
 	{
@@ -127,6 +144,12 @@ return {
 			return Nil:new()
 		end
 	},
+	{
+		"has", "(t::table, key)",
+		function(state, t, k)
+			return Boolean:new(t:has(state, k))
+		end
+	},
 	{
 		"to struct", "(t::table)",
 		function(state, t)
diff --git a/anselme/stdlib/symbol.lua b/anselme/stdlib/symbol.lua
new file mode 100644
index 0000000..e5e22dd
--- /dev/null
+++ b/anselme/stdlib/symbol.lua
@@ -0,0 +1,9 @@
+return {
+
+	{
+		"to string", "(symbol::symbol)",
+		function(state, sym)
+			return sym:to_string()
+		end
+	},
+}
diff --git a/test/results/constrained variable assignement.ans b/test/results/constrained variable assignement.ans
index 8944dc7..87f10fc 100644
--- a/test/results/constrained variable assignement.ans	
+++ b/test/results/constrained variable assignement.ans	
@@ -1,8 +1,8 @@
 --# run #--
 --- text ---
-| {}"" {}"type(\"kg\", 5)" {}"" |
+| {}"" {}"type(5, \"kg\")" {}"" |
 --- text ---
-| {}"" {}"type(\"kg\", 12)" {}"" |
+| {}"" {}"type(12, \"kg\")" {}"" |
 --- error ---
 type check failure for weigh; 32 does not satisfy $(x) type(x) == t
 	↳ from test/tests/constrained variable assignement.ans:9:7 in assignment: weigh = 32
diff --git a/test/results/constrained variable definition.ans b/test/results/constrained variable definition.ans
index 89ad27f..c81a028 100644
--- a/test/results/constrained variable definition.ans	
+++ b/test/results/constrained variable definition.ans	
@@ -1,6 +1,6 @@
 --# run #--
 --- text ---
-| {}"" {}"type(\"kg\", 5)" {}"" |
+| {}"" {}"type(5, \"kg\")" {}"" |
 --- text ---
 | {}"" {}"12" {}"" |
 --- return ---
diff --git a/test/results/exported variable nested.ans b/test/results/exported variable nested.ans
index 900b8f1..d355df6 100644
--- a/test/results/exported variable nested.ans	
+++ b/test/results/exported variable nested.ans	
@@ -5,7 +5,7 @@
 --- text ---
 | {}"" {}"42" {}"" |
 --- error ---
-identifier "z" is undefined in branch cf017f8a-7c86-4871-109af-6658231331e6
+identifier "z" is undefined in branch 7dfcaa5b-2163-4f36-116ed-c4ab6bc8d28b
 	↳ from test/tests/exported variable nested.ans:12:3 in identifier: z
 	↳ from test/tests/exported variable nested.ans:12:1 in text interpolation: | {z} |
 	↳ from ? in block: :f = ($() _)…
diff --git a/test/results/for break.ans b/test/results/for break.ans
new file mode 100644
index 0000000..1c15f56
--- /dev/null
+++ b/test/results/for break.ans	
@@ -0,0 +1,8 @@
+--# run #--
+--- text ---
+| {}"" {}"1" {}"" |
+| {}"" {}"2" {}"" |
+--- return ---
+()
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/for continue.ans b/test/results/for continue.ans
new file mode 100644
index 0000000..63ad50d
--- /dev/null
+++ b/test/results/for continue.ans	
@@ -0,0 +1,9 @@
+--# run #--
+--- text ---
+| {}"" {}"1" {}"" |
+| {}"" {}"2" {}"" |
+| {}"" {}"4" {}"" |
+--- return ---
+()
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/for invalid iterator.ans b/test/results/for invalid iterator.ans
new file mode 100644
index 0000000..23f29df
--- /dev/null
+++ b/test/results/for invalid iterator.ans	
@@ -0,0 +1,15 @@
+--# run #--
+--- error ---
+can't call overload overload<($(table::($(x) <lua function>)) _), ($(tuple::($(x) type(x) == "tuple" | type(x) == "list")) _), ($(range::($(x) type(x) == t)) _), ($(s::($(x) <lua function>)) <lua function>)>: no function match (42), possible functions were:
+	• (table::($(x) <lua function>)): type check failure for parameter table in function (table::($(x) <lua function>))
+	• (tuple::($(x) type(x) == "tuple" | type(x) == "list")): type check failure for parameter tuple in function (tuple::($(x) type(x) == "tuple" | type(x) == "list"))
+	• (range::($(x) type(x) == t)): type check failure for parameter range in function (range::($(x) type(x) == t))
+	• (s::($(x) <lua function>)): type check failure for parameter s in function (s::($(x) <lua function>))
+	↳ from for.ans:3:18 in call: iter(var)
+	↳ from for.ans:3:12 in definition: :iterator = iter(var)
+	↳ from for.ans:2:1 in block: :iterator = iter(var)…
+	↳ from for.ans:2:68 in call: _
+	↳ from test/tests/for invalid iterator.ans:1:4 in call: for(:x, 42)
+	↳ from ? in block: for(:x, 42)…
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/for list.ans b/test/results/for list.ans
new file mode 100644
index 0000000..b1af884
--- /dev/null
+++ b/test/results/for list.ans	
@@ -0,0 +1,10 @@
+--# run #--
+--- text ---
+| {}"" {}"7" {}"" |
+| {}"" {}"96" {}"" |
+| {}"" {}"a" {}"" |
+| {}"" {}"3" {}"" |
+--- return ---
+()
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/for range.ans b/test/results/for range.ans
new file mode 100644
index 0000000..8454397
--- /dev/null
+++ b/test/results/for range.ans	
@@ -0,0 +1,38 @@
+--# run #--
+--- text ---
+| {}"-" |
+| {}"" {}"1" {}"" |
+| {}"" {}"2" {}"" |
+| {}"" {}"3" {}"" |
+| {}"" {}"4" {}"" |
+| {}"" {}"5" {}"" |
+--- text ---
+| {}"-" |
+| {}"" {}"2" {}"" |
+| {}"" {}"3" {}"" |
+| {}"" {}"4" {}"" |
+| {}"" {}"5" {}"" |
+| {}"" {}"6" {}"" |
+| {}"" {}"7" {}"" |
+--- text ---
+| {}"-" |
+| {}"" {}"2" {}"" |
+| {}"" {}"5" {}"" |
+--- text ---
+| {}"-" |
+| {}"" {}"4" {}"" |
+| {}"" {}"3" {}"" |
+| {}"" {}"2" {}"" |
+| {}"" {}"1" {}"" |
+| {}"" {}"0" {}"" |
+--- text ---
+| {}"-" |
+--- text ---
+| {}"-" |
+--- text ---
+| {}"-" |
+| {}"" {}"4" {}"" |
+--- return ---
+()
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/for struct.ans b/test/results/for struct.ans
new file mode 100644
index 0000000..d4df120
--- /dev/null
+++ b/test/results/for struct.ans	
@@ -0,0 +1,10 @@
+--# run #--
+--- text ---
+| {}"" {}"true" |
+| {}"" {}"true" |
+| {}"" {}"true" |
+| {}"" {}"true" |
+--- return ---
+()
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/for table.ans b/test/results/for table.ans
new file mode 100644
index 0000000..d4df120
--- /dev/null
+++ b/test/results/for table.ans	
@@ -0,0 +1,10 @@
+--# run #--
+--- text ---
+| {}"" {}"true" |
+| {}"" {}"true" |
+| {}"" {}"true" |
+| {}"" {}"true" |
+--- return ---
+()
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/for tuple.ans b/test/results/for tuple.ans
new file mode 100644
index 0000000..d019a24
--- /dev/null
+++ b/test/results/for tuple.ans	
@@ -0,0 +1,11 @@
+--# run #--
+--- text ---
+| {}"" {}"2" {}"" |
+| {}"" {}"5" {}"" |
+| {}"" {}"7" {}"" |
+| {}"" {}"1" {}"" |
+| {}"" {}"8" {}"" |
+--- return ---
+()
+--# saved #--
+{}
\ No newline at end of file
diff --git a/test/results/function custom type dispatch error.ans b/test/results/function custom type dispatch error.ans
index 0f10730..69da3e9 100644
--- a/test/results/function custom type dispatch error.ans	
+++ b/test/results/function custom type dispatch error.ans	
@@ -4,7 +4,7 @@
 --- text ---
 | {}"" {}"idk" {}" is esperanto" |
 --- error ---
-can't call overload overload<($(name::($(x) type(x) == t)) _), ($(name::($(x) type(x) == t)) _)>: no function match (type("nope", 5)), possible functions were:
+can't call overload overload<($(name::($(x) type(x) == t)) _), ($(name::($(x) type(x) == t)) _)>: no function match (type(5, "nope")), possible functions were:
 	• (name::($(x) type(x) == t)): type check failure for parameter name in function (name::($(x) type(x) == t))
 	• (name::($(x) type(x) == t)): type check failure for parameter name in function (name::($(x) type(x) == t))
 	↳ from test/tests/function custom type dispatch error.ans:14:2 in call: a(type(5, "nope"))
diff --git a/test/results/function random.ans b/test/results/function random.ans
index e23a436..15a5220 100644
--- a/test/results/function random.ans	
+++ b/test/results/function random.ans	
@@ -1,15 +1,15 @@
 --# run #--
 --- text ---
-| {}"c" |
---- text ---
-| {}"b" |
---- text ---
 | {}"a" |
 --- text ---
-| {}"b" |
+| {}"c" |
 --- text ---
-| {}"b" |
+| {}"a" |
+--- text ---
+| {}"a" |
+--- text ---
+| {}"c" |
 --- return ---
 ()
 --# saved #--
-{"a.checkpoint":false, "a.run":1, "b.checkpoint":false, "b.run":3, "c.checkpoint":false, "c.run":1}
\ No newline at end of file
+{"a.checkpoint":false, "a.run":3, "c.checkpoint":false, "c.run":2}
\ No newline at end of file
diff --git a/test/results/function scope wrong.ans b/test/results/function scope wrong.ans
index 2d30e80..7bfde1c 100644
--- a/test/results/function scope wrong.ans	
+++ b/test/results/function scope wrong.ans	
@@ -1,6 +1,6 @@
 --# run #--
 --- error ---
-identifier "b" is undefined in branch cf017f8a-7c86-4871-109af-6658231331e6
+identifier "b" is undefined in branch 7dfcaa5b-2163-4f36-116ed-c4ab6bc8d28b
 	↳ from test/tests/function scope wrong.ans:4:7 in identifier: b
 	↳ from test/tests/function scope wrong.ans:4:1 in text interpolation: | a: {b} |
 	↳ from ? in block: :a = ($() _)…
diff --git a/test/tests/for break.ans b/test/tests/for break.ans
new file mode 100644
index 0000000..7b5569b
--- /dev/null
+++ b/test/tests/for break.ans	
@@ -0,0 +1,4 @@
+for(:x, range(10))
+	if(x == 3)
+		break!
+	|{x}
\ No newline at end of file
diff --git a/test/tests/for continue.ans b/test/tests/for continue.ans
new file mode 100644
index 0000000..38c530f
--- /dev/null
+++ b/test/tests/for continue.ans	
@@ -0,0 +1,4 @@
+for(:x, range(4))
+	if(x == 3)
+		continue!
+	|{x}
diff --git a/test/tests/for invalid iterator.ans b/test/tests/for invalid iterator.ans
new file mode 100644
index 0000000..93b88f7
--- /dev/null
+++ b/test/tests/for invalid iterator.ans	
@@ -0,0 +1,2 @@
+for(:x, 42)
+	|{x}
diff --git a/test/tests/for list.ans b/test/tests/for list.ans
new file mode 100644
index 0000000..0096d5b
--- /dev/null
+++ b/test/tests/for list.ans	
@@ -0,0 +1,4 @@
+:l = *[7,96,"a",3]
+
+for(:x, l)
+	|{x}
diff --git a/test/tests/for range.ans b/test/tests/for range.ans
new file mode 100644
index 0000000..940cd4f
--- /dev/null
+++ b/test/tests/for range.ans	
@@ -0,0 +1,27 @@
+|-
+for(:x, range(5))
+	|{x}
+
+|-
+for(:y, range(2, 7))
+	|{y}
+
+|-
+for(:z, range(2, 7, 3))
+	|{z}
+
+|-
+for(:x, range(4, 0, -1))
+	|{x}
+
+|-
+for(:x, range(4, 8, -1))
+	|{x}
+
+|-
+for(:x, range(8, 4))
+	|{x}
+
+|-
+for(:x, range(4, 4))
+	|{x}
diff --git a/test/tests/for struct.ans b/test/tests/for struct.ans
new file mode 100644
index 0000000..444439c
--- /dev/null
+++ b/test/tests/for struct.ans	
@@ -0,0 +1,7 @@
+:s = { "a":"b", 6:"c", 98:5, true:3 }
+:t = *s
+
+/* struct iteration is non deterministic, too lazy to sort, so we check if we have 4 key that each appear at most once */
+for(:k, s)
+	|{t!has(k)}|
+	t(k) = ()
diff --git a/test/tests/for table.ans b/test/tests/for table.ans
new file mode 100644
index 0000000..335b2a9
--- /dev/null
+++ b/test/tests/for table.ans	
@@ -0,0 +1,6 @@
+:s = *{ "a":"b", 6:"c", 98:5, true:3 }
+
+/* struct iteration is non deterministic, too lazy to sort, so we check if we have 4 key that each appear at most once */
+for(:k, s)
+	|{s!has(k)}|
+	s(k) = ()
diff --git a/test/tests/for tuple.ans b/test/tests/for tuple.ans
new file mode 100644
index 0000000..2ee1ffc
--- /dev/null
+++ b/test/tests/for tuple.ans	
@@ -0,0 +1,4 @@
+:t = [2,5,7,1,8]
+
+for(:x, t)
+	|{x}