Debug.

packages/Floats.sty

@@ -19,6 +19,25 @@
 \floatstyle{plain}
 \newfloat{generic}{htpb}{lgf}
 
+% Function for converting clists generated by multichoice keys into strings.
+\NewDocumentCommand{\clist_use_default:Nnnn}{
+	% #1: Output string variable.
+	m
+	% #2: Input clist.
+	m
+	% #3: Default clist to use if #2 is empty.
+	m
+	% #4: Separator for \clist_use:Nn.
+	O{}
+}{
+	\clist_if_empty:NT #2 {
+		\clist_set:Ne #2 {#3}
+	}
+	\str_set:Ne #1 {
+		\clist_use:Nn #2 {#4}
+	}
+}
+
 % Maximum width adjustment to fit 2 16x9 screensots on one page.
 \dim_const:Nn \c_BigFloat_overhang_dim {0.54in}
 \str_const:Nn \c_BigFloat_type_str {generic}
@@ -57,10 +76,9 @@
 	+b
 }{%
 	\keys_set:nn{BigFloat}{#1}%
-	%\str_new:N \l_BigFloat_placement_str
-	\str_set:Ne \l_BigFloat_placement_str {
-		\clist_use:Nn \c_BigFloat_placement_clist {}
-	}
+	\clist_use_default:Nnnn \l_BigFloat_placement_str
+		{\l_BigFloat_placement_clist}
+		{\c_BigFloat_placement_clist}
 	\ExpEnvOption%
 	\begin{\l_BigFloat_type_str}[\l_BigFloat_placement_str]% float environment
 		\begin{SmartAdjustWidth}{%
@@ -88,11 +106,11 @@
 
 \clist_const:Nn \c_CenterFig_placement_clist {h, t, p, b}
 
-\str_new:N \l_CenterFig_placement_str
+\clist_new:N \l_CenterFig_placement_clist
 
 \keys_define:nn{CenterFig}{
-	placement	.multichoices:nn	= {b,H,h,p,t}{
-		\str_put_right:Ne \l_CenterFig_placement_str {\l_keys_choice_tl}
+	placement	.multichoices:nn= {b,H,h,p,t}{
+		\clist_put_right:Nn \l_CenterFig_placement_clist {\l_keys_choice_tl}
 	},
 }
 
@@ -109,11 +127,9 @@
 	m
 }{
 	\keys_set:nn{CenterFig}{#2}%
-	\str_if_empty:NT \l_CenterFig_placement_str {
-		\str_set:Ne \l_CenterFig_placement_str {
-			\clist_use:Nn \c_CenterFig_placement_clist {}
-		}
-	}
+	\clist_use_default:Nnnn \l_CenterFig_placement_str
+		{\l_CenterFig_placement_clist}
+		{\c_CenterFig_placement_clist}
 	\ExpEnvOption
 	\begin{figure}[\l_CenterFig_placement_str]%
 		\Centering%