commit 68b8a5ccf03f309fbfe3d3d8119e252f60cdb571
author Gavin Howard <yzena.tech@gmail.com> Thu Feb 15 11:41:24 2018 -0700
committer Gavin Howard <yzena.tech@gmail.com> Tue Aug 28 17:10:23 2018 -0600
tree 222cd6b4f4bb088b293abfaa49fa3691cc44d93d
parent 0b465d022f50be82ca90f24abf395f5cd893f761

Add functions to convert to longs

include/bc/bc.h

diff --git a/include/bc/bc.h b/include/bc/bc.h
index 1a2b7c3..b4ae8b9 100644
--- a/include/bc/bc.h
+++ b/include/bc/bc.h
@@ -111,6 +111,9 @@
   BC_STATUS_PARSE_EOF,
   BC_STATUS_PARSE_BUG,
 
+  BC_STATUS_MATH_NEGATIVE,
+  BC_STATUS_MATH_NON_INTEGER,
+  BC_STATUS_MATH_OVERFLOW,
   BC_STATUS_MATH_DIVIDE_BY_ZERO,
   BC_STATUS_MATH_NEG_SQRT,
   BC_STATUS_MATH_INVALID_STRING,

include/bc/num.h

diff --git a/include/bc/num.h b/include/bc/num.h
index 288b929..172b0ca 100644
--- a/include/bc/num.h
+++ b/include/bc/num.h
@@ -105,6 +105,9 @@
 BcStatus bc_num_print(BcNum* n, size_t base);
 BcStatus bc_num_fprint(BcNum* n, size_t base, FILE* f);
 
+BcStatus bc_num_long(BcNum* n, long* result);
+BcStatus bc_num_ulong(BcNum* n, unsigned long* result);
+
 BcStatus bc_num_add(BcNum* a, BcNum* b, BcNum* result, size_t scale);
 BcStatus bc_num_sub(BcNum* a, BcNum* b, BcNum* result, size_t scale);
 BcStatus bc_num_mul(BcNum* a, BcNum* b, BcNum* result, size_t scale);

src/bc/bc.c

diff --git a/src/bc/bc.c b/src/bc/bc.c
index 9a4e8a0..d4af68a 100644
--- a/src/bc/bc.c
+++ b/src/bc/bc.c
@@ -99,6 +99,8 @@
   "Math",
   "Math",
   "Math",
+  "Math",
+  "Math",
 
   "Runtime",
   "Runtime",
@@ -175,10 +177,11 @@
   "end of file",
   "bug in parser",
 
+  "negative number",
+  "non integer number",
+  "overflow",
   "divide by zero",
   "negative square root",
-  "invalid input base",
-  "invalid output base",
   "invalid number string",
 
   "couldn't open file",

src/bc/num.c

diff --git a/src/bc/num.c b/src/bc/num.c
index 64e3a83..28009e8 100644
--- a/src/bc/num.c
+++ b/src/bc/num.c
@@ -212,6 +212,59 @@
   return status;
 }
 
+BcStatus bc_num_long(BcNum* n, long* result) {
+
+  size_t i;
+  unsigned long temp;
+  unsigned long prev;
+
+  if (!n || !result) return BC_STATUS_INVALID_PARAM;
+
+  if (n->radix != n->len) return BC_STATUS_MATH_NON_INTEGER;
+
+  temp = 0;
+
+  for (i = 0; i < n->len; ++i) {
+
+    prev = temp;
+
+    temp *= 10;
+    temp += n->num[i];
+
+    if (temp < prev) return BC_STATUS_MATH_OVERFLOW;
+  }
+
+  *result = temp;
+
+  return BC_STATUS_SUCCESS;
+}
+
+BcStatus bc_num_ulong(BcNum* n, unsigned long* result) {
+
+  size_t i;
+  unsigned long prev;
+
+  if (!n || !result) return BC_STATUS_INVALID_PARAM;
+
+  if (n->radix != n->len) return BC_STATUS_MATH_NON_INTEGER;
+
+  if (n->neg) return BC_STATUS_MATH_NEGATIVE;
+
+  *result = 0;
+
+  for (i = 0; i < n->len; ++i) {
+
+    prev = *result;
+
+    *result *= 10;
+    *result += n->num[i];
+
+    if (*result < prev) return BC_STATUS_MATH_OVERFLOW;
+  }
+
+  return BC_STATUS_SUCCESS;
+}
+
 BcStatus bc_num_add(BcNum* a, BcNum* b, BcNum* result, size_t scale) {
   return bc_num_binary(a, b, result, scale, bc_num_alg_a, a->len + b->len + 1);
 }