From c700b7d91d9cc50ae6f3ca5fd47758df1c532b48 Mon Sep 17 00:00:00 2001
From: Vivianne Langdon <puttabutta@gmail.com>
Date: Fri, 1 Mar 2024 17:04:46 -0500
Subject: [PATCH] Throw an error message that is more helpful when type is
 wrong

---
 termenv/style.scm | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/termenv/style.scm b/termenv/style.scm
index fae34c8..ee5d232 100644
--- a/termenv/style.scm
+++ b/termenv/style.scm
@@ -70,28 +70,29 @@
 
 (set-record-type-printer! <style> style->sequence)
 
-(define (cons-seq stylish sequence)
+(define (cons-sequence stylish sequence)
   (match stylish
     ((? string? str)
      (make-style str (list sequence)))
     ((style)
-     (cons-seq style sequence))
+     (cons-sequence style sequence))
     ((? list? l)
-     (make-style-node (map (cut cons-seq <> sequence) l)))
+     (make-style-node (map (cut cons-sequence <> sequence) l)))
     ((? style? style)
      (set-style-sequences style
       (cons* sequence (style-sequences style))))
     ((? style-node? node)
      (set-style-node-children node
-      (map (cut cons-seq <> sequence) (style-node-children node))))))
+      (map (cut cons-sequence <> sequence) (style-node-children node))))
+    (anything-else (scm-error 'wrong-type-arg "cons-sequence" "Expected either a string or a style node (created by functions `bold', `italic', etc), got ~S" (list anything-else) (list anything-else)))))
 
-(define (bold . s) (cons-seq s %BOLD))
-(define (faint . s) (cons-seq s %FAINT))
-(define (italic . s) (cons-seq s %ITALIC))
-(define (underline . s) (cons-seq s %UNDERLINE))
-(define (overline . s) (cons-seq s %OVERLINE))
-(define (blink . s) (cons-seq s %BLINK))
-(define (invert . s) (cons-seq s %REVERSE))
-(define (cross-out . s) (cons-seq s %CROSS-OUT))
-(define (foreground c . s) (cons-seq s (make-foreground c)))
-(define (background c . s) (cons-seq s (make-background c)))
+(define (bold . s) (cons-sequence s %BOLD))
+(define (faint . s) (cons-sequence s %FAINT))
+(define (italic . s) (cons-sequence s %ITALIC))
+(define (underline . s) (cons-sequence s %UNDERLINE))
+(define (overline . s) (cons-sequence s %OVERLINE))
+(define (blink . s) (cons-sequence s %BLINK))
+(define (invert . s) (cons-sequence s %REVERSE))
+(define (cross-out . s) (cons-sequence s %CROSS-OUT))
+(define (foreground c . s) (cons-sequence s (make-foreground c)))
+(define (background c . s) (cons-sequence s (make-background c)))