add `buffer/from-bytes`

src/core/buffer.c

@@ -221,6 +221,20 @@ JANET_CORE_FN(cfun_buffer_new_filled,
     return janet_wrap_buffer(buffer);
 }
 
+JANET_CORE_FN(cfun_buffer_frombytes,
+              "(buffer/from-bytes & byte-vals)",
+              "Creates a buffer from integer parameters with byte values. All integers "
+              "will be coerced to the range of 1 byte 0-255.") {
+    int32_t i;
+    JanetBuffer *buffer = janet_buffer(argc);
+    for (i = 0; i < argc; i++) {
+        int32_t c = janet_getinteger(argv, i);
+        buffer->data[i] = c & 0xFF;
+    }
+    buffer->count = argc;
+    return janet_wrap_buffer(buffer);
+}
+
 JANET_CORE_FN(cfun_buffer_fill,
               "(buffer/fill buffer &opt byte)",
               "Fill up a buffer with bytes, defaulting to 0s. Does not change the buffer's length. "
@@ -509,6 +523,7 @@ void janet_lib_buffer(JanetTable *env) {
     JanetRegExt buffer_cfuns[] = {
         JANET_CORE_REG("buffer/new", cfun_buffer_new),
         JANET_CORE_REG("buffer/new-filled", cfun_buffer_new_filled),
+        JANET_CORE_REG("buffer/from-bytes", cfun_buffer_frombytes),
         JANET_CORE_REG("buffer/fill", cfun_buffer_fill),
         JANET_CORE_REG("buffer/trim", cfun_buffer_trim),
         JANET_CORE_REG("buffer/push-byte", cfun_buffer_u8),

test/suite-buffer.janet

@@ -77,6 +77,14 @@
 (buffer/push-string b5 "456" @"789")
 (assert (= "123456789" (string b5)) "buffer/push-buffer 2")
 
+# Buffer from bytes
+(assert (deep= @"" (buffer/from-bytes)) "buffer/from-bytes 1")
+(assert (deep= @"ABC" (buffer/from-bytes 65 66 67)) "buffer/from-bytes 2")
+(assert (deep= @"0123456789" (buffer/from-bytes ;(range 48 58))) "buffer/from-bytes 3")
+(assert (= 0 (length (buffer/from-bytes))) "buffer/from-bytes 4")
+(assert (= 5 (length (buffer/from-bytes ;(range 5)))) "buffer/from-bytes 5")
+(assert-error "bad slot #1, expected 32 bit signed integer" (buffer/from-bytes :abc))
+
 # some tests for buffer/format
 # 029394d
 (assert (= (string (buffer/format @"" "pi = %6.3f" math/pi)) "pi =  3.142")
@@ -114,8 +122,5 @@
 (assert (deep= @"abc423" (buffer/push-at @"abc123" 3 "4"))
         "buffer/push-at 3")
 
-# 4782a76
-(assert (= 10 (do (var x 10) (def y x) (++ x) y)) "no invalid aliasing")
-
 (end-suite)
 

test/suite-unknown.janet

@@ -292,5 +292,8 @@
                  [2 6 4 'z]])
         "arg & inner symbolmap")
 
+# 4782a76
+(assert (= 10 (do (var x 10) (def y x) (++ x) y)) "no invalid aliasing")
+
 (end-suite)