implemented generic clip function in stdlib_math.fypp

Author: aman-godara

src/stdlib_math.fypp

@@ -0,0 +1,42 @@
+#:include "common.fypp"
+
+#:set INT_KINDS_TYPES = [('int8', 'integer'), (int16, 'integer'), ('int32', 'integer'), (int64, 'integer')]
+#:set REAL_KINDS_TYPES = [('sp', 'real'), ('dp', 'real'), ('qp', 'real')]
+
+#:set IR_KINDS_TYPES = INT_KINDS_TYPES + REAL_KINDS_TYPES
+module stdlib_math
+    use stdlib_kinds, only: int8, int16, int32, int64, sp, dp, qp
+
+    implicit none
+    private
+    public :: clip
+
+
+    interface clip
+    #:for k1, t1 in IR_KINDS_TYPES
+    #:set RName = rname('clip', t1, k1)
+        module function ${RName}$(x, xmin, xmax) result(res)
+            ${t1}$(${k1}$), intent(in) :: x
+            ${t1}$(${k1}$), intent(in) :: xmin
+            ${t1}$(${k1}$), intent(in) :: xmax
+            ${t1}$(${k1}$) :: res
+        end function ${RName}$
+    #:endfor
+    end interface clip
+
+
+    contains
+        #:for k1, t1 in IR_KINDS_TYPES
+        #:set RName = rname('clip', t1, k1)
+        elemental function ${RName}$(x, xmin, xmax) result(res)
+            ! I hope that I am not required to redefine these inputs and output again, because I have already
+            ! done that in the interface
+            res = max(min(x, xmax), xmin)
+        end function ${RName}$
+        #:endfor
+
+        ! What should I do if xmin(int8) is given with xmax(int16) as inputs:
+        ! will fortran automatically convert xmin(int8) to xmin(int16) ??
+        ! OR, I will have to take care of that explicity by not specifying 
+        ! kind for xmin, xmax and x in line 17, 18, and 19.
+end module stdlib_math