diff --git a/examples/lang/env1.mcl b/examples/lang/env1.mcl
index aa57c2cb..e1beafcd 100644
--- a/examples/lang/env1.mcl
+++ b/examples/lang/env1.mcl
@@ -2,7 +2,7 @@ import "fmt"
 import "sys"
 
 $env = sys.env()
-$m = maplookup($env, "GOPATH", "")
+$m = map_lookup_optional($env, "GOPATH", "")
 
 print "print0" {
 	msg => if sys.hasenv("GOPATH") {
diff --git a/examples/lang/maplookup1.mcl b/examples/lang/maplookup1.mcl
index 12f1a366..7843673e 100644
--- a/examples/lang/maplookup1.mcl
+++ b/examples/lang/maplookup1.mcl
@@ -2,13 +2,13 @@ import "fmt"
 
 $m = {"k1" => 42, "k2" => 13,}
 
-$found = maplookup($m, "k1", 99)
+$found = map_lookup_optional($m, "k1", 99)
 
 print "print1" {
 	msg => fmt.printf("found value of: %d", $found),
 }
 
-$notfound = maplookup($m, "k3", 99)
+$notfound = map_lookup_optional($m, "k3", 99)
 
 print "print2" {
 	msg => fmt.printf("notfound value of: %d", $notfound),
diff --git a/examples/lang/sendrecv1.mcl b/examples/lang/sendrecv1.mcl
index 076846b2..4bb29f82 100644
--- a/examples/lang/sendrecv1.mcl
+++ b/examples/lang/sendrecv1.mcl
@@ -3,7 +3,7 @@ import "world"
 
 $ns = "estate"
 $exchanged = world.kvlookup($ns)
-$state = maplookup($exchanged, $hostname, "default")
+$state = map_lookup_optional($exchanged, $hostname, "default")
 
 exec "exec0" {
 	cmd => "echo hello world && echo goodbye world 1>&2", # to stdout && stderr
diff --git a/examples/lang/states0.mcl b/examples/lang/states0.mcl
index db856860..f7c3dc65 100644
--- a/examples/lang/states0.mcl
+++ b/examples/lang/states0.mcl
@@ -2,7 +2,7 @@ import "world"
 
 $ns = "estate"
 $exchanged = world.kvlookup($ns)
-$state = maplookup($exchanged, $hostname, "default")
+$state = map_lookup_optional($exchanged, $hostname, "default")
 
 if $state == "one" or $state == "default" {
 
diff --git a/lang/funcs/listlookup_func.go b/lang/funcs/list_lookup_default_func.go
similarity index 88%
rename from lang/funcs/listlookup_func.go
rename to lang/funcs/list_lookup_default_func.go
index f4066554..ca1d512a 100644
--- a/lang/funcs/listlookup_func.go
+++ b/lang/funcs/list_lookup_default_func.go
@@ -28,26 +28,25 @@ import (
 )
 
 const (
-	// ListLookupFuncName is the name this function is registered as. This
-	// starts with an underscore so that it cannot be used from the lexer.
-	// XXX: change to _listlookup and add syntax in the lexer/parser
-	ListLookupFuncName = "listlookup"
+	// ListLookupDefaultFuncName is the name this function is registered as.
+	ListLookupDefaultFuncName = "list_lookup_default"
 
 	// arg names...
-	listLookupArgNameList    = "list"
-	listLookupArgNameIndex   = "index"
-	listLookupArgNameDefault = "default"
+	listLookupDefaultArgNameList    = "list"
+	listLookupDefaultArgNameIndex   = "index"
+	listLookupDefaultArgNameDefault = "default"
 )
 
 func init() {
-	Register(ListLookupFuncName, func() interfaces.Func { return &ListLookupFunc{} }) // must register the func and name
+	Register(ListLookupDefaultFuncName, func() interfaces.Func { return &ListLookupDefaultFunc{} }) // must register the func and name
 }
 
-var _ interfaces.PolyFunc = &ListLookupFunc{} // ensure it meets this expectation
+var _ interfaces.PolyFunc = &ListLookupDefaultFunc{} // ensure it meets this expectation
 
-// ListLookupFunc is a list index lookup function. If you provide a negative
-// index, then it will return the default value you specified for this function.
-type ListLookupFunc struct {
+// ListLookupDefaultFunc is a list index lookup function. If you provide a
+// negative index, then it will return the default value you specified for this
+// function.
+type ListLookupDefaultFunc struct {
 	Type *types.Type // Kind == List, that is used as the list we lookup in
 
 	init *interfaces.Init
@@ -58,13 +57,13 @@ type ListLookupFunc struct {
 
 // String returns a simple name for this function. This is needed so this struct
 // can satisfy the pgraph.Vertex interface.
-func (obj *ListLookupFunc) String() string {
-	return ListLookupFuncName
+func (obj *ListLookupDefaultFunc) String() string {
+	return ListLookupDefaultFuncName
 }
 
 // ArgGen returns the Nth arg name for this function.
-func (obj *ListLookupFunc) ArgGen(index int) (string, error) {
-	seq := []string{listLookupArgNameList, listLookupArgNameIndex, listLookupArgNameDefault}
+func (obj *ListLookupDefaultFunc) ArgGen(index int) (string, error) {
+	seq := []string{listLookupDefaultArgNameList, listLookupDefaultArgNameIndex, listLookupDefaultArgNameDefault}
 	if l := len(seq); index >= l {
 		return "", fmt.Errorf("index %d exceeds arg length of %d", index, l)
 	}
@@ -72,7 +71,7 @@ func (obj *ListLookupFunc) ArgGen(index int) (string, error) {
 }
 
 // Unify returns the list of invariants that this func produces.
-func (obj *ListLookupFunc) Unify(expr interfaces.Expr) ([]interfaces.Invariant, error) {
+func (obj *ListLookupDefaultFunc) Unify(expr interfaces.Expr) ([]interfaces.Invariant, error) {
 	var invariants []interfaces.Invariant
 	var invar interfaces.Invariant
 
@@ -346,7 +345,7 @@ func (obj *ListLookupFunc) Unify(expr interfaces.Expr) ([]interfaces.Invariant,
 // and must be run before Info() and any of the other Func interface methods are
 // used. This function is idempotent, as long as the arg isn't changed between
 // runs.
-func (obj *ListLookupFunc) Build(typ *types.Type) (*types.Type, error) {
+func (obj *ListLookupDefaultFunc) Build(typ *types.Type) (*types.Type, error) {
 	// typ is the KindFunc signature we're trying to build...
 	if typ.Kind != types.KindFunc {
 		return nil, fmt.Errorf("input type must be of kind func")
@@ -394,7 +393,7 @@ func (obj *ListLookupFunc) Build(typ *types.Type) (*types.Type, error) {
 }
 
 // Validate tells us if the input struct takes a valid form.
-func (obj *ListLookupFunc) Validate() error {
+func (obj *ListLookupDefaultFunc) Validate() error {
 	if obj.Type == nil { // build must be run first
 		return fmt.Errorf("type is still unspecified")
 	}
@@ -406,7 +405,7 @@ func (obj *ListLookupFunc) Validate() error {
 
 // Info returns some static info about itself. Build must be called before this
 // will return correct data.
-func (obj *ListLookupFunc) Info() *interfaces.Info {
+func (obj *ListLookupDefaultFunc) Info() *interfaces.Info {
 	var sig *types.Type
 	if obj.Type != nil { // don't panic if called speculatively
 		// TODO: can obj.Type.Key or obj.Type.Val be nil (a partial) ?
@@ -421,19 +420,19 @@ func (obj *ListLookupFunc) Info() *interfaces.Info {
 }
 
 // helper
-func (obj *ListLookupFunc) sig() *types.Type {
+func (obj *ListLookupDefaultFunc) sig() *types.Type {
 	v := obj.Type.Val.String()
-	return types.NewType(fmt.Sprintf("func(%s %s, %s int, %s %s) %s", listLookupArgNameList, obj.Type.String(), listLookupArgNameIndex, listLookupArgNameDefault, v, v))
+	return types.NewType(fmt.Sprintf("func(%s %s, %s int, %s %s) %s", listLookupDefaultArgNameList, obj.Type.String(), listLookupDefaultArgNameIndex, listLookupDefaultArgNameDefault, v, v))
 }
 
 // Init runs some startup code for this function.
-func (obj *ListLookupFunc) Init(init *interfaces.Init) error {
+func (obj *ListLookupDefaultFunc) Init(init *interfaces.Init) error {
 	obj.init = init
 	return nil
 }
 
 // Stream returns the changing values that this func has over time.
-func (obj *ListLookupFunc) Stream(ctx context.Context) error {
+func (obj *ListLookupDefaultFunc) Stream(ctx context.Context) error {
 	defer close(obj.init.Output) // the sender closes
 	for {
 		select {
@@ -450,9 +449,9 @@ func (obj *ListLookupFunc) Stream(ctx context.Context) error {
 			}
 			obj.last = input // store for next
 
-			l := (input.Struct()[listLookupArgNameList]).(*types.ListValue)
-			index := input.Struct()[listLookupArgNameIndex].Int()
-			def := input.Struct()[listLookupArgNameDefault]
+			l := (input.Struct()[listLookupDefaultArgNameList]).(*types.ListValue)
+			index := input.Struct()[listLookupDefaultArgNameIndex].Int()
+			def := input.Struct()[listLookupDefaultArgNameDefault]
 
 			// TODO: should we handle overflow by returning default?
 			if index > math.MaxInt { // max int size varies by arch
diff --git a/lang/funcs/maplookup_func.go b/lang/funcs/map_lookup_default_func.go
similarity index 87%
rename from lang/funcs/maplookup_func.go
rename to lang/funcs/map_lookup_default_func.go
index 106223bb..1848d27c 100644
--- a/lang/funcs/maplookup_func.go
+++ b/lang/funcs/map_lookup_default_func.go
@@ -27,25 +27,24 @@ import (
 )
 
 const (
-	// MapLookupFuncName is the name this function is registered as. This
-	// starts with an underscore so that it cannot be used from the lexer.
-	// XXX: change to _maplookup and add syntax in the lexer/parser
-	MapLookupFuncName = "maplookup"
+	// MapLookupDefaultFuncName is the name this function is registered as.
+	MapLookupDefaultFuncName = "map_lookup_default"
 
 	// arg names...
-	mapLookupArgNameMap = "map"
-	mapLookupArgNameKey = "key"
-	mapLookupArgNameDef = "default"
+	mapLookupDefaultArgNameMap = "map"
+	mapLookupDefaultArgNameKey = "key"
+	mapLookupDefaultArgNameDef = "default"
 )
 
 func init() {
-	Register(MapLookupFuncName, func() interfaces.Func { return &MapLookupFunc{} }) // must register the func and name
+	Register(MapLookupDefaultFuncName, func() interfaces.Func { return &MapLookupDefaultFunc{} }) // must register the func and name
 }
 
-var _ interfaces.PolyFunc = &MapLookupFunc{} // ensure it meets this expectation
+var _ interfaces.PolyFunc = &MapLookupDefaultFunc{} // ensure it meets this expectation
 
-// MapLookupFunc is a key map lookup function.
-type MapLookupFunc struct {
+// MapLookupDefaultFunc is a key map lookup function. If you provide a missing
+// key, then it will return the default value you specified for this function.
+type MapLookupDefaultFunc struct {
 	Type *types.Type // Kind == Map, that is used as the map we lookup
 
 	init *interfaces.Init
@@ -56,13 +55,13 @@ type MapLookupFunc struct {
 
 // String returns a simple name for this function. This is needed so this struct
 // can satisfy the pgraph.Vertex interface.
-func (obj *MapLookupFunc) String() string {
-	return MapLookupFuncName
+func (obj *MapLookupDefaultFunc) String() string {
+	return MapLookupDefaultFuncName
 }
 
 // ArgGen returns the Nth arg name for this function.
-func (obj *MapLookupFunc) ArgGen(index int) (string, error) {
-	seq := []string{mapLookupArgNameMap, mapLookupArgNameKey, mapLookupArgNameDef}
+func (obj *MapLookupDefaultFunc) ArgGen(index int) (string, error) {
+	seq := []string{mapLookupDefaultArgNameMap, mapLookupDefaultArgNameKey, mapLookupDefaultArgNameDef}
 	if l := len(seq); index >= l {
 		return "", fmt.Errorf("index %d exceeds arg length of %d", index, l)
 	}
@@ -70,7 +69,7 @@ func (obj *MapLookupFunc) ArgGen(index int) (string, error) {
 }
 
 // Unify returns the list of invariants that this func produces.
-func (obj *MapLookupFunc) Unify(expr interfaces.Expr) ([]interfaces.Invariant, error) {
+func (obj *MapLookupDefaultFunc) Unify(expr interfaces.Expr) ([]interfaces.Invariant, error) {
 	var invariants []interfaces.Invariant
 	var invar interfaces.Invariant
 
@@ -370,7 +369,7 @@ func (obj *MapLookupFunc) Unify(expr interfaces.Expr) ([]interfaces.Invariant, e
 // Polymorphisms returns the list of possible function signatures available for
 // this static polymorphic function. It relies on type and value hints to limit
 // the number of returned possibilities.
-func (obj *MapLookupFunc) Polymorphisms(partialType *types.Type, partialValues []types.Value) ([]*types.Type, error) {
+func (obj *MapLookupDefaultFunc) Polymorphisms(partialType *types.Type, partialValues []types.Value) ([]*types.Type, error) {
 	// TODO: return `variant` as arg for now -- maybe there's a better way?
 	variant := []*types.Type{types.NewType("func(map variant, key variant, default variant) variant")}
 
@@ -435,20 +434,20 @@ func (obj *MapLookupFunc) Polymorphisms(partialType *types.Type, partialValues [
 	typFunc := &types.Type{
 		Kind: types.KindFunc, // function type
 		Map:  make(map[string]*types.Type),
-		Ord:  []string{mapLookupArgNameMap, mapLookupArgNameKey, mapLookupArgNameDef},
+		Ord:  []string{mapLookupDefaultArgNameMap, mapLookupDefaultArgNameKey, mapLookupDefaultArgNameDef},
 		Out:  nil,
 	}
-	typFunc.Map[mapLookupArgNameMap] = typ
-	typFunc.Map[mapLookupArgNameKey] = typ.Key
-	typFunc.Map[mapLookupArgNameDef] = typ.Val
+	typFunc.Map[mapLookupDefaultArgNameMap] = typ
+	typFunc.Map[mapLookupDefaultArgNameKey] = typ.Key
+	typFunc.Map[mapLookupDefaultArgNameDef] = typ.Val
 	typFunc.Out = typ.Val
 
 	// TODO: don't include partial internal func map's for now, allow in future?
 	if typ.Key == nil || typ.Val == nil {
 		typFunc.Map = make(map[string]*types.Type) // erase partial
-		typFunc.Map[mapLookupArgNameMap] = types.TypeVariant
-		typFunc.Map[mapLookupArgNameKey] = types.TypeVariant
-		typFunc.Map[mapLookupArgNameDef] = types.TypeVariant
+		typFunc.Map[mapLookupDefaultArgNameMap] = types.TypeVariant
+		typFunc.Map[mapLookupDefaultArgNameKey] = types.TypeVariant
+		typFunc.Map[mapLookupDefaultArgNameDef] = types.TypeVariant
 	}
 	if typ.Val == nil {
 		typFunc.Out = types.TypeVariant
@@ -469,7 +468,7 @@ func (obj *MapLookupFunc) Polymorphisms(partialType *types.Type, partialValues [
 // and must be run before Info() and any of the other Func interface methods are
 // used. This function is idempotent, as long as the arg isn't changed between
 // runs.
-func (obj *MapLookupFunc) Build(typ *types.Type) (*types.Type, error) {
+func (obj *MapLookupDefaultFunc) Build(typ *types.Type) (*types.Type, error) {
 	// typ is the KindFunc signature we're trying to build...
 	if typ.Kind != types.KindFunc {
 		return nil, fmt.Errorf("input type must be of kind func")
@@ -517,7 +516,7 @@ func (obj *MapLookupFunc) Build(typ *types.Type) (*types.Type, error) {
 }
 
 // Validate tells us if the input struct takes a valid form.
-func (obj *MapLookupFunc) Validate() error {
+func (obj *MapLookupDefaultFunc) Validate() error {
 	if obj.Type == nil { // build must be run first
 		return fmt.Errorf("type is still unspecified")
 	}
@@ -529,7 +528,7 @@ func (obj *MapLookupFunc) Validate() error {
 
 // Info returns some static info about itself. Build must be called before this
 // will return correct data.
-func (obj *MapLookupFunc) Info() *interfaces.Info {
+func (obj *MapLookupDefaultFunc) Info() *interfaces.Info {
 	var sig *types.Type
 	if obj.Type != nil { // don't panic if called speculatively
 		// TODO: can obj.Type.Key or obj.Type.Val be nil (a partial) ?
@@ -544,20 +543,20 @@ func (obj *MapLookupFunc) Info() *interfaces.Info {
 }
 
 // helper
-func (obj *MapLookupFunc) sig() *types.Type {
+func (obj *MapLookupDefaultFunc) sig() *types.Type {
 	k := obj.Type.Key.String()
 	v := obj.Type.Val.String()
-	return types.NewType(fmt.Sprintf("func(%s %s, %s %s, %s %s) %s", mapLookupArgNameMap, obj.Type.String(), mapLookupArgNameKey, k, mapLookupArgNameDef, v, v))
+	return types.NewType(fmt.Sprintf("func(%s %s, %s %s, %s %s) %s", mapLookupDefaultArgNameMap, obj.Type.String(), mapLookupDefaultArgNameKey, k, mapLookupDefaultArgNameDef, v, v))
 }
 
 // Init runs some startup code for this function.
-func (obj *MapLookupFunc) Init(init *interfaces.Init) error {
+func (obj *MapLookupDefaultFunc) Init(init *interfaces.Init) error {
 	obj.init = init
 	return nil
 }
 
 // Stream returns the changing values that this func has over time.
-func (obj *MapLookupFunc) Stream(ctx context.Context) error {
+func (obj *MapLookupDefaultFunc) Stream(ctx context.Context) error {
 	defer close(obj.init.Output) // the sender closes
 	for {
 		select {
@@ -574,9 +573,9 @@ func (obj *MapLookupFunc) Stream(ctx context.Context) error {
 			}
 			obj.last = input // store for next
 
-			m := (input.Struct()[mapLookupArgNameMap]).(*types.MapValue)
-			key := input.Struct()[mapLookupArgNameKey]
-			def := input.Struct()[mapLookupArgNameDef]
+			m := (input.Struct()[mapLookupDefaultArgNameMap]).(*types.MapValue)
+			key := input.Struct()[mapLookupDefaultArgNameKey]
+			def := input.Struct()[mapLookupDefaultArgNameDef]
 
 			var result types.Value
 			val, exists := m.Lookup(key)
diff --git a/lang/funcs/structlookup_func.go b/lang/funcs/struct_lookup_func.go
similarity index 99%
rename from lang/funcs/structlookup_func.go
rename to lang/funcs/struct_lookup_func.go
index ebed6cc4..e5a27847 100644
--- a/lang/funcs/structlookup_func.go
+++ b/lang/funcs/struct_lookup_func.go
@@ -29,8 +29,7 @@ import (
 const (
 	// StructLookupFuncName is the name this function is registered as. This
 	// starts with an underscore so that it cannot be used from the lexer.
-	// XXX: change to _structlookup and add syntax in the lexer/parser
-	StructLookupFuncName = "structlookup"
+	StructLookupFuncName = "_struct_lookup"
 
 	// arg names...
 	structLookupArgNameStruct = "struct"
diff --git a/lang/interpret_test/TestAstFunc1/slow_unification0.txtar b/lang/interpret_test/TestAstFunc1/slow_unification0.txtar
index d13216a8..0afe342b 100644
--- a/lang/interpret_test/TestAstFunc1/slow_unification0.txtar
+++ b/lang/interpret_test/TestAstFunc1/slow_unification0.txtar
@@ -4,7 +4,7 @@ import "world"
 
 $ns = "estate"
 $exchanged = world.kvlookup($ns)
-$state = maplookup($exchanged, $hostname, "default")
+$state = map_lookup_optional($exchanged, $hostname, "default")
 
 if $state == "one" or $state == "default" {
 
diff --git a/lang/interpret_test/TestAstFunc2/complex-example.txtar b/lang/interpret_test/TestAstFunc2/complex-example.txtar
index 197e7612..f073a967 100644
--- a/lang/interpret_test/TestAstFunc2/complex-example.txtar
+++ b/lang/interpret_test/TestAstFunc2/complex-example.txtar
@@ -18,8 +18,8 @@ $foo = iter.map([$id1, $id2,], $generate)
 
 #test $foo[0] {}
 #test $foo[1] {}
-test listlookup($foo, 0, "fail") {} # TODO: add syntactic sugar for listlookup
-test listlookup($foo, 1, "fail") {} # TODO: add syntactic sugar for listlookup
+test list_lookup_optional($foo, 0, "fail") {} # TODO: add syntactic sugar for list_lookup_optional
+test list_lookup_optional($foo, 1, "fail") {} # TODO: add syntactic sugar for list_lookup_optional
 -- OUTPUT --
 Vertex: test[foo]
 Vertex: test[foofoo]
diff --git a/lang/interpret_test/TestAstFunc2/listlookup.txtar b/lang/interpret_test/TestAstFunc2/listlookup.txtar
index 2a258d70..ab6a92db 100644
--- a/lang/interpret_test/TestAstFunc2/listlookup.txtar
+++ b/lang/interpret_test/TestAstFunc2/listlookup.txtar
@@ -5,10 +5,10 @@ $l2 = [$l1, ["hello", "world",],]
 
 #test $l1[0] {}
 #test $l1[1] {}
-test listlookup($l1, 0, "fail") {} # TODO: add syntactic sugar for listlookup
-test listlookup($l1, 2, "fail") {} # TODO: add syntactic sugar for listlookup
-test listlookup($l1, 3, "pass") {} # TODO: add syntactic sugar for listlookup
-test listlookup($l2, 1, ["fail",]) {} # TODO: add syntactic sugar for listlookup
+test list_lookup_optional($l1, 0, "fail") {} # TODO: add syntactic sugar for list_lookup_optional
+test list_lookup_optional($l1, 2, "fail") {} # TODO: add syntactic sugar for list_lookup_optional
+test list_lookup_optional($l1, 3, "pass") {} # TODO: add syntactic sugar for list_lookup_optional
+test list_lookup_optional($l2, 1, ["fail",]) {} # TODO: add syntactic sugar for list_lookup_optional
 -- OUTPUT --
 Vertex: test[a]
 Vertex: test[c]
diff --git a/lang/interpret_test/TestAstFunc2/maplookup0.txtar b/lang/interpret_test/TestAstFunc2/maplookup0.txtar
index d1bb0890..cfda5f69 100644
--- a/lang/interpret_test/TestAstFunc2/maplookup0.txtar
+++ b/lang/interpret_test/TestAstFunc2/maplookup0.txtar
@@ -1,15 +1,15 @@
 -- main.mcl --
 $map1 map{int: str} = {42 => "hello1",}
-test maplookup($map1, 42, "not found") {}
+test map_lookup_optional($map1, 42, "not found") {}
 
 $map2 map{int: str} = {42 => "hello2",}
-test maplookup($map2, 13, "world2") {}
+test map_lookup_optional($map2, 13, "world2") {}
 
 $map3 = {42 => "hello3",}
-test maplookup($map3, 42, "not found") {}
+test map_lookup_optional($map3, 42, "not found") {}
 
 $map4 = {42 => "hello4",}
-test maplookup($map4, 13, "world4") {}
+test map_lookup_optional($map4, 13, "world4") {}
 -- OUTPUT --
 Vertex: test[hello1]
 Vertex: test[hello3]
diff --git a/lang/interpret_test/TestAstFunc2/very-complex-example.txtar b/lang/interpret_test/TestAstFunc2/very-complex-example.txtar
index 94843f0a..1e60037c 100644
--- a/lang/interpret_test/TestAstFunc2/very-complex-example.txtar
+++ b/lang/interpret_test/TestAstFunc2/very-complex-example.txtar
@@ -73,6 +73,6 @@ $generate = func($idn) {
 $foo = iter.map([$id1, $id2,], $generate)
 
 #test $foo[0] {}
-test listlookup($foo, 0, "fail") {} # TODO: add syntactic sugar for listlookup
+test list_lookup_optional($foo, 0, "fail") {} # TODO: add syntactic sugar for list_lookup_optional
 -- OUTPUT --
 # err: errUnify: can't unify, invariant illogicality with equals: base kind does not match (Str != Int)
diff --git a/test/shell/env0.mcl b/test/shell/env0.mcl
index 26fec8f2..a3730087 100644
--- a/test/shell/env0.mcl
+++ b/test/shell/env0.mcl
@@ -15,7 +15,7 @@ $t = sys.hasenv("TEST")
 $f = sys.hasenv("DOESNOTEXIST")
 
 $env = sys.env()
-$m = maplookup($env, "TEST", "321")
+$m = map_lookup_optional($env, "TEST", "321")
 
 file "${tmpdir}/environ" {
 	state => $const.res.file.state.exists,