Lots of stuff.

packages/LadderLogic.sty

@@ -0,0 +1,63 @@
+\NeedsTeXFormat{LaTeX2e}
+\ProvidesExplPackage{PrimeTeX/packages/LadderLogic}{2025-09-24}{1.0}{
+	Macros for tikz-ladder Ladder Logic diagrams.
+}
+
+\fp_const:Nn \c_LadderLogic_inline_scale_fp {0.6}
+
+\cs_new:Nn \__LadderLogic_inline_format: {
+	\scriptsize\sffamily
+}
+
+\cs_new:Nn \__LadderLogic_default_format: {
+	\sffamily
+}
+
+\NewDocumentCommand{\LadderFormat}{O{} O{}}{
+	\str_case:nnF {#1} {
+		{default} {
+			\str_if_empty:nTF {#2} {
+				\__LadderLogic_default_format:
+			} {
+				\cs_set:Nn \__LadderLogic_default_format: {#2}
+			}
+		}
+		{inline} {
+			\str_if_empty:nTF {#2} {
+				\__LadderLogic_inline_format:
+			} {
+				\cs_set:Nn \__LadderLogic_inline_format: {#2}
+			}
+		}
+	} { % case else
+		\__LadderLogic_default_format:
+	}
+}
+
+% It seems TikZ declarations have to be in the document environment?
+\AtBeginDocument{
+	\usetikzlibrary{circuits.plc.ladder}
+
+	\NewDocumentCommand{\LadderInlineElement}{
+		O{\c_LadderLogic_inline_scale_fp}
+		m
+	}{
+		\group_begin:
+			\LadderInlineRung[#1]{
+				\draw(0,0)
+					to [#2] ++(1,0);
+			}
+		\group_end:
+	}
+
+	\NewDocumentCommand{\LadderInlineRung}{
+		O{\c_LadderLogic_inline_scale_fp}
+		m
+	}{
+		\group_begin:
+			\__LadderLogic_inline_format:
+			\tikzset{circuit~symbol~unit=\fp_to_dim:n {#1 * \baselineskip}}
+			\raisebox{\c_InlineGraphic_offset_dim}{\tikz[circuit~plc~ladder,thick]{#2}}
+		\group_end:
+	}
+}