From 9635c223b1d39d753afbe23406b45c58dfa38f8f Mon Sep 17 00:00:00 2001
From: Victor Akpan <67718730+victorakpan-dev@users.noreply.github.com>
Date: Wed, 30 Mar 2022 18:44:01 +0100
Subject: [PATCH] Added new Math functions (#160)

* Added log and round functions to math module

* Added log and round functions to math module

* Added a few math functions

* Static checks

* Maybe this will fix linux

* Fixed errors with styles and tests
---
 src/pk_core.c      | 93 +++++++++++++++++++++++++++++++++++++++++++++-
 tests/lang/core.pk | 17 +++++++++
 2 files changed, 109 insertions(+), 1 deletion(-)

diff --git a/src/pk_core.c b/src/pk_core.c
index 97c4cf7..3bed1f1 100644
--- a/src/pk_core.c
+++ b/src/pk_core.c
@@ -1049,7 +1049,8 @@ DEF(stdMathArcTangent,
 
 DEF(stdMathLog10,
   "log10(value:num) -> num\n"
-  "Return the logarithm to base 10 of argument [value]") {
+  "Return the logarithm to base 10 of argument [value]"
+  ) {
 
   double num;
   if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
@@ -1065,6 +1066,89 @@ DEF(stdMathRound,
   RET(VAR_NUM(round(num)));
 }
 
+DEF(stdMathLog2,
+  "log2(value:num) -> num\n"
+  "Returns the logarithm to base 2 of the argument [value]"
+  ) {
+
+  double num;
+  if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
+  RET(VAR_NUM(log2(num)));
+}
+
+DEF(stdMathHypot,
+  "hypot(x:num,y:num) -> num\n"
+  "Returns the hypotenuse of a right-angled triangle with side [x] and [y]"
+  ) {
+
+  double x, y;
+  if (!validateNumeric(vm, ARG(1), &x, "Argument 1")) return;
+  if (!validateNumeric(vm, ARG(2), &y, "Argument 2")) return;
+  RET(VAR_NUM(hypot(x, y)));
+}
+
+DEF(stdMathCbrt,
+  "cbrt(value:num) -> num\n"
+  "Returns the cuberoot of argument [value]"
+  ) {
+
+  double num;
+  if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
+  RET(VAR_NUM(cbrt(num)));
+}
+
+DEF(stdMathGamma,
+  "gamma(value:num) -> num\n"
+  "Returns the gamma function of argument [value]"
+  ) {
+
+  double num;
+  if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
+  RET(VAR_NUM(tgamma(num)));
+}
+
+#if defined(__USE_GNU) || defined(__USE_BSD)
+DEF(stdMathGamma,
+  "gamma(value:num) -> num\n"
+  "Returns the gamma function of argument [value]"
+  ) {
+
+  double num;
+  if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
+  RET(VAR_NUM(gamma(num)));
+}
+#endif
+
+DEF(stdMathLgamma,
+  "lgamma(value:num) -> num\n"
+  "Returns the complementary gamma function of argument [value]"
+  ) {
+
+  double num;
+  if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
+  RET(VAR_NUM(lgamma(num)));
+}
+
+DEF(stdMathErf,
+  "erf(value:num) -> num\n"
+  "Returns the error function of argument [value]"
+  ) {
+
+  double num;
+  if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
+  RET(VAR_NUM(erf(num)));
+}
+
+DEF(stdMathErfc,
+  "erfc(value:num) -> num\n"
+  "Returns the complementary error function of argument [value]"
+  ) {
+
+  double num;
+  if (!validateNumeric(vm, ARG(1), &num, "Argument 1")) return;
+  RET(VAR_NUM(erfc(num)));
+}
+
 // 'Fiber' module methods.
 // -----------------------
 
@@ -1210,6 +1294,13 @@ void initializeCore(PKVM* vm) {
   MODULE_ADD_FN(math, "atan",  stdMathArcTangent,  1);
   MODULE_ADD_FN(math, "log10", stdMathLog10,       1);
   MODULE_ADD_FN(math, "round", stdMathRound,       1);
+  MODULE_ADD_FN(math, "log2",  stdMathLog2,        1);
+  MODULE_ADD_FN(math, "hypot", stdMathHypot,       2);
+  MODULE_ADD_FN(math, "cbrt",  stdMathCbrt,        1);
+  MODULE_ADD_FN(math, "gamma", stdMathGamma,       1);
+  MODULE_ADD_FN(math, "lgamma",stdMathLgamma,      1);
+  MODULE_ADD_FN(math, "erf",   stdMathErf,         1);
+  MODULE_ADD_FN(math, "erfc",  stdMathErfc,        1);
 
   // Note that currently it's mutable (since it's a global variable, not
   // constant and pocketlang doesn't support constant) so the user shouldn't
diff --git a/tests/lang/core.pk b/tests/lang/core.pk
index 9bd5fae..40c4f99 100644
--- a/tests/lang/core.pk
+++ b/tests/lang/core.pk
@@ -84,6 +84,23 @@ assert(round(1.4) == 1)
 assert(round(1.5) == 2)
 assert(round(-1.5) == -2)
 
+assert(abs(log2(2) - 1) < threshold)
+assert(abs(log2(1) - 0) < threshold)
+assert(abs(log2(5) - 2.321928094887362) < threshold)
+
+assert(abs(hypot(1,1) - 1.414213562373095) < threshold)
+assert(abs(hypot(3,5) - 5.830951894845301) < threshold)
+
+assert(abs(cbrt(27) - 3) < threshold)
+assert(abs(cbrt(9) - 2.080083823051904) < threshold)
+
+assert(abs(gamma(5) - 24) < threshold)
+assert(abs(gamma(2.2) - 1.101802490879713) < threshold)
+
+
+
+
+
 # If we got here, that means all test were passed.
 print('All TESTS PASSED')