Add array/trim and buffer/trim.

CHANGELOG.md

@@ -1,6 +1,10 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## Unreleased - ???
+- Add `array/trim` and `buffer/trim` to shrink the backing capacity of these types
+  to their current length.
+
 ## 1.10.0 - 2020-06-14
 - Hardcode default jpm paths on install so env variables are needed in fewer cases.
 - Add `:no-compile` to `create-executable` option for jpm.

meson.build

@@ -20,7 +20,7 @@
 
 project('janet', 'c',
   default_options : ['c_std=c99', 'b_lundef=false', 'default_library=both'],
-  version : '1.10.0')
+  version : '1.10.1-dev')
 
 # Global settings
 janet_path = join_paths(get_option('prefix'), get_option('libdir'), 'janet')

src/conf/janetconf.h

@@ -28,9 +28,9 @@
 
 #define JANET_VERSION_MAJOR 1
 #define JANET_VERSION_MINOR 10
-#define JANET_VERSION_PATCH 0
+#define JANET_VERSION_PATCH 1
-#define JANET_VERSION_EXTRA ""
+#define JANET_VERSION_EXTRA "-dev"
-#define JANET_VERSION "1.10.0"
+#define JANET_VERSION "1.10.1-dev"
 
 /* #define JANET_BUILD "local" */
 

src/core/array.c

@@ -270,6 +270,26 @@ static Janet cfun_array_remove(int32_t argc, Janet *argv) {
     return argv[0];
 }
 
+static Janet cfun_array_trim(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
+    JanetArray *array = janet_getarray(argv, 0);
+    if (array->count) {
+        if (array->count < array->capacity) {
+            Janet *newData = realloc(array->data, array->count * sizeof(Janet));
+            if (NULL == newData) {
+                JANET_OUT_OF_MEMORY;
+            }
+            array->data = newData;
+            array->capacity = array->count;
+        }
+    } else {
+        array->capacity = 0;
+        free(array->data);
+        array->data = NULL;
+    }
+    return argv[0];
+}
+
 static const JanetReg array_cfuns[] = {
     {
         "array/new", cfun_array_new,
@@ -345,6 +365,11 @@ static const JanetReg array_cfuns[] = {
              "By default, n is 1. "
              "Returns the array.")
     },
+    {
+        "array/trim", cfun_array_trim,
+        JDOC("(array/trim arr)\n\n"
+             "Set the backing capacity of an array to its current length. Returns the modified array.")
+    },
     {NULL, NULL, NULL}
 };
 

src/core/buffer.c

@@ -197,6 +197,26 @@ static Janet cfun_buffer_fill(int32_t argc, Janet *argv) {
     return argv[0];
 }
 
+static Janet cfun_buffer_trim(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
+    JanetBuffer *buffer = janet_getbuffer(argv, 0);
+    if (buffer->count) {
+        if (buffer->count < buffer->capacity) {
+            uint8_t *newData = realloc(buffer->data, buffer->count);
+            if (NULL == newData) {
+                JANET_OUT_OF_MEMORY;
+            }
+            buffer->data = newData;
+            buffer->capacity = buffer->count;
+        }
+    } else {
+        buffer->capacity = 0;
+        free(buffer->data);
+        buffer->data = NULL;
+    }
+    return argv[0];
+}
+
 static Janet cfun_buffer_u8(int32_t argc, Janet *argv) {
     int32_t i;
     janet_arity(argc, 1, -1);
@@ -379,6 +399,12 @@ static const JanetReg buffer_cfuns[] = {
              "Fill up a buffer with bytes, defaulting to 0s. Does not change the buffer's length. "
              "Returns the modified buffer.")
     },
+    {
+        "buffer/trim", cfun_buffer_trim,
+        JDOC("(buffer/trim buffer)\n\n"
+             "Set the backing capacity of the buffer to the current length of the buffer. Returns the "
+             "modified buffer.")
+    },
     {
         "buffer/push-byte", cfun_buffer_u8,
         JDOC("(buffer/push-byte buffer x)\n\n"