From fc6647fbb3058e5eb1c3079c93428c845c4523b9 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Sat, 6 Feb 2016 03:19:36 -0500
Subject: [PATCH] Added (record?)

---
 debug/kons.scm       |  2 ++
 scheme/base.sld      | 15 +++++++++------
 srfi/9.sld           |  6 ++++++
 tests/unit-tests.scm |  2 ++
 4 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/debug/kons.scm b/debug/kons.scm
index f8672e6d..d1cd89a2 100644
--- a/debug/kons.scm
+++ b/debug/kons.scm
@@ -22,6 +22,8 @@
     (let ((k (kons 1 2)))
       (set-kar! k 3)
       (kar k)) ;=. 3
+    (record? (kons 1 2))
+    (record? (cons 1 2))
 ))
 
 ;(define <pare> (register-simple-type <pare> #f (quote (x y)))) 
diff --git a/scheme/base.sld b/scheme/base.sld
index 4a76a310..266a1eec 100644
--- a/scheme/base.sld
+++ b/scheme/base.sld
@@ -182,9 +182,17 @@
 ;    open-input-string
 ;    open-output-string
 ;
-; for a lot of the following, need begin-splicing, or syntax-rules
+;    ;; no binary/text ports yet
 ;    binary-port?
+;    textual-port?
+;
+;    ;; syntax-rules
+;    syntax-error
+;    syntax-rules
+;    parameterize
 ;    define-values
+;
+; for a lot of the following, need begin-splicing, or syntax-rules
 ;    guard
 ;    import
 ;    include
@@ -193,11 +201,6 @@
 ;    let-values
 ;    letrec*
 ;    letrec-syntax
-;    parameterize
-;    record?
-;    syntax-error
-;    syntax-rules
-;    textual-port?
 ;;;;
   )
   (begin
diff --git a/srfi/9.sld b/srfi/9.sld
index db4f6386..c85d594c 100644
--- a/srfi/9.sld
+++ b/srfi/9.sld
@@ -4,6 +4,7 @@
 ;;; This is based on the implementation of SRFI 9 from chibi scheme
 (define-library (srfi 9)
   (export 
+    record?
     define-record-type
     register-simple-type
     make-type-predicate
@@ -51,6 +52,11 @@
       (lambda (obj val)
         (vector-set! (vector-ref obj 2) idx val)))
 
+    (define (record? obj)
+      (and (vector? obj)
+           (> (vector-length obj) 0)
+           (equal? record-marker (vector-ref obj 0))))
+
     (define-syntax define-record-type
       (er-macro-transformer
        (lambda (expr rename compare)
diff --git a/tests/unit-tests.scm b/tests/unit-tests.scm
index f6f2981f..171ff155 100644
--- a/tests/unit-tests.scm
+++ b/tests/unit-tests.scm
@@ -336,6 +336,8 @@
     (set-kar! k 3)
     (kar k))
   3)
+(assert:equal "Record type predicate (t)" (record? (kons 1 2)) #t)
+(assert:equal "Record type predicate (f)" (record? (cons 1 2)) #f)
 ;; END records
 
 ; TODO: use display, output without surrounding quotes