From 4300a759e39c853b1c1ff4c44abe234a911a9022 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Thu, 11 Apr 2019 13:53:26 -0400
Subject: [PATCH] Emit sexp along with arg error

---
 scheme/cyclone/cps-optimizations.sld | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/scheme/cyclone/cps-optimizations.sld b/scheme/cyclone/cps-optimizations.sld
index 6c6ff4d5..71517274 100644
--- a/scheme/cyclone/cps-optimizations.sld
+++ b/scheme/cyclone/cps-optimizations.sld
@@ -2403,6 +2403,8 @@
              (expected-argc (length (ast:lambda-args lam)))
              (argc (- (length ast) 1)) )
      (when (not (= argc expected-argc))
+       (compiler-msg "Compiler Error: ")
+       (compiler-msg ast)
        (compiler-error 
         "Expected "
         (number->string expected-argc)
@@ -2419,4 +2421,21 @@
   (newline (current-error-port))
   (exit 1))
 
+;; Display a compilation message to the user
+(define (compiler-msg . sexp)
+  (display (apply sexp->string sexp) (current-error-port))
+  (newline (current-error-port)))
+
+;; Convert given scheme expressions to a string, via (display)
+;; TODO: move to util module
+(define (sexp->string . sexps)
+  (let ((p (open-output-string)))
+    (for-each
+      (lambda (sexp)
+        (apply display (cons sexp (list p))))
+      sexps)
+    (let ((result (get-output-string p)))
+      (close-port p)
+      result)))
+
 ))