ba_check_and_set_bit (#54)

* add bit array check and set
* update changelog

Author: barrust

CHANGELOG.md

@@ -1,5 +1,22 @@
 # C-Utils
 
+## Version 0.2.5
+
+***Updates:***
+
+*c-utils*
+* Add check and set function to return value of bit prior to setting
+
+*fileutils*
+* Add `fs_is_symlink()` function to check if a file or directory is actually a symlink
+
+*strlib*
+* Better memory check for `s_append_alt()`
+
+*graph*
+* Cleaned-up a re-used variable name to ensure no confusion for the user
+
+
 ## Version 0.2.4
 ***New Libraries:***
 * permutations
@@ -23,7 +40,6 @@
 * Fix output for `between` checks on failed assertion
 
 
-
 ## Version 0.2.3
 ***Updates:***
 
@@ -54,14 +70,14 @@
 ## Version 0.2.1
 ***Updates:***
 
-*Graph:*
+*graph*
 * Traversal of the graph from a particular vertex
 * Breadth First
 * Depth First
 * OpenMP support
 
-*StringLib:*
-* Micro optimizations for s_trim and s_standardize_whitespace
+*stringlib:*
+* Micro optimizations for `s_trim` and `s_standardize_whitespace`
 
 
 ## Version 0.2.0

src/bitarray.c

@@ -85,6 +85,13 @@ int ba_check_bit(bitarray_t ba, size_t bit) {
     return (CHECK_BIT(ba->arr, bit) != 0) ? BIT_SET : BIT_NOT_SET;
 }
 
+int ba_check_and_set_bit(bitarray_t ba, size_t bit) {
+    int is_set = ba_check_bit(ba, bit);
+
+    if (is_set == BIT_NOT_SET)
+        ba_set_bit(ba, bit);
+    return is_set;
+}
 
 int ba_toggle_bit(bitarray_t ba, size_t bit) {
     if (bit >= ba->num_bits)

src/bitarray.h

@@ -6,7 +6,7 @@
 ***  Author: Tyler Barrus
 ***  email:  barrust@gmail.com
 ***
-***  Version: 0.1.1
+***  Version: 0.1.2
 ***  Purpose: Simple bit array library
 ***
 ***  License: MIT 2019
@@ -56,6 +56,10 @@ int ba_set_bit(bitarray_t ba, size_t bit);
     BIT_NOT_SET if false */
 int ba_check_bit(bitarray_t ba, size_t bit);
 
+/*  Check if bit `bit` was previously set; return BIT_SET if true and
+    BIT_NOT_SET if false and set the bit to 1 */
+int ba_check_and_set_bit(bitarray_t ba, size_t bit);
+
 /*  Toggle the bit by setting it to BIT_NOT_SET if currently is BIT_SET or
     vice versa; returns the updated value of the bit */
 int ba_toggle_bit(bitarray_t ba, size_t bit);

tests/bitarray_test.c

@@ -65,6 +65,31 @@ MU_TEST(test_check_bit) {
     ba_free(ba);
 }
 
+/*******************************************************************************
+*   Test check and set bit
+*******************************************************************************/
+MU_TEST(test_check_and_set_bit) {
+    bitarray_t ba = ba_init(125);  /* bit array of length 125 */
+    int res;
+    res = ba_set_bit(ba, 0);
+    res = ba_set_bit(ba, 50);
+    res = ba_set_bit(ba, 75);
+
+    /* check out of bounds still caught */
+    res = ba_check_and_set_bit(ba, 125);
+    mu_assert_int_eq(BITARRAY_INDEX_ERROR, res);
+
+    res = ba_check_and_set_bit(ba, 0);
+    mu_assert_int_eq(BIT_SET, res);
+
+    res = ba_check_and_set_bit(ba, 55);
+    mu_assert_int_eq(BIT_NOT_SET, res);
+
+    res = ba_check_and_set_bit(ba, 55);
+    mu_assert_int_eq(BIT_SET, res);
+
+    ba_free(ba);
+}
 
 /*******************************************************************************
 *   Test clear bit
@@ -189,6 +214,7 @@ MU_TEST_SUITE(test_suite) {
     MU_RUN_TEST(test_default_setup);
     MU_RUN_TEST(test_set_bit);
     MU_RUN_TEST(test_check_bit);
+    MU_RUN_TEST(test_check_and_set_bit);
     MU_RUN_TEST(test_clear_bit);
     MU_RUN_TEST(test_reset_bitarray);
     MU_RUN_TEST(test_print_array);