From d791077e2583c94ebc0c9a3a8ac55e9f656217b3 Mon Sep 17 00:00:00 2001
From: Calvin Rose <calsrose@gmail.com>
Date: Fri, 23 Nov 2018 15:33:49 -0500
Subject: [PATCH] Fix abstract? function.

---
 src/core/core.janet | 1 -
 src/core/corelib.c  | 9 +++++++++
 test/suite2.janet   | 9 +++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/core/core.janet b/src/core/core.janet
index 78ad1d5b..fc25d2dc 100644
--- a/src/core/core.janet
+++ b/src/core/core.janet
@@ -102,7 +102,6 @@
 (defn function? "Check if x is a function (not a cfunction)."
   [x] (= (type x) :function))
 (defn cfunction? "Check if x a cfunction." [x] (= (type x) :cfunction))
-(defn abstract? "Check if x an abstract type." [x] (= (type x) :abstract))
 (defn table? [x] "Check if x a table." (= (type x) :table ))
 (defn struct? [x] "Check if x a struct." (= (type x) :struct))
 (defn array? [x] "Check if x is an array." (= (type x) :array))
diff --git a/src/core/corelib.c b/src/core/corelib.c
index e23c151e..ba01ad8d 100644
--- a/src/core/corelib.c
+++ b/src/core/corelib.c
@@ -148,6 +148,11 @@ static int janet_core_buffer(JanetArgs args) {
     JANET_RETURN_BUFFER(args, b);
 }
 
+static int janet_core_is_abstract(JanetArgs args) {
+    JANET_FIXARITY(args, 1);
+    JANET_RETURN_BOOLEAN(args, janet_checktype(args.v[0], JANET_ABSTRACT));
+}
+
 static int janet_core_scannumber(JanetArgs args) {
     const uint8_t *data;
     Janet x;
@@ -320,6 +325,10 @@ static const JanetReg cfuns[] = {
         "converted to bytes via describe if they are not byte sequences. Returns "
         "the new symbol."
     },
+    {"abstract?", janet_core_is_abstract,
+        "(abstract? x)\n\n"
+        "Check if x is an abstract type."
+    },
     {"table", janet_core_table,
         "(table & kvs)\n\n"
         "Creates a new table from a variadic number of keys and values. "
diff --git a/test/suite2.janet b/test/suite2.janet
index 42477cb9..f2aa8090 100644
--- a/test/suite2.janet
+++ b/test/suite2.janet
@@ -82,5 +82,14 @@
 (assert (deep= (string.find-all "e" "onetwothree") @[2 9 10]) "string.find-all 1")
 (assert (deep= (string.find-all "," "onetwothree") @[]) "string.find-all 2")
 
+# Check if abstract test works
+(assert (abstract? stdout) "abstract? stdout")
+(assert (abstract? stdin) "abstract? stdin")
+(assert (abstract? stderr) "abstract? stderr")
+(assert (not (abstract? nil)) "not abstract? nil")
+(assert (not (abstract? 1)) "not abstract? 1")
+(assert (not (abstract? 3)) "not abstract? 3")
+(assert (not (abstract? 5)) "not abstract? 5")
+
 (end-suite)