Merge remote-tracking branch 'upstream/master' into Distribution-Uniform

Author: Jim-215-Fisher

CHANGELOG.md

@@ -0,0 +1,93 @@
+# Unreleased
+
+- new module `stdlib_ascii`
+  [#32](https://github.com/fortran-lang/stdlib/pull/32)
+- new module `stdlib_bitsets`
+  [#239](https://github.com/fortran-lang/stdlib/pull/239)
+  - new derived types `bitset_64` and `bitset_large`
+  - new abstract base class `bitset_type`
+- new module `stdlib_error`
+  [#53](https://github.com/fortran-lang/stdlib/pull/53)
+- new module `stdlib_io`
+  - new procedures `loadtxt` and `savetxt`
+    [#23](https://github.com/fortran-lang/stdlib/pull/23)
+    [#37](https://github.com/fortran-lang/stdlib/pull/37)
+  - new procedure `open`
+    [#71](https://github.com/fortran-lang/stdlib/pull/71)
+    [#77](https://github.com/fortran-lang/stdlib/pull/77)
+- new module `stdlib_kinds`
+  [#63](https://github.com/fortran-lang/stdlib/pull/63)
+- new module `stdlib_linalg`
+  - new procedures `diag`, `eye` and `trace`
+    [#170](https://github.com/fortran-lang/stdlib/pull/170)
+  - new procedures `linspace` and `logspace`
+    [#420](https://github.com/fortran-lang/stdlib/pull/420)
+  - new procedure `outer_product`
+    [#432](https://github.com/fortran-lang/stdlib/pull/432)
+  - new procedure `arange`
+    [#480](https://github.com/fortran-lang/stdlib/pull/480)
+- new module `stdlib_logger`
+  - new derived type: `logger_type`
+    [#228](https://github.com/fortran-lang/stdlib/pull/228)
+    [#261](https://github.com/fortran-lang/stdlib/pull/261)
+- new module `stdlib_math`
+  - new procedure `clip`
+    [#355](https://github.com/fortran-lang/stdlib/pull/355)
+- new module `stdlib_optval`
+  [#73](https://github.com/fortran-lang/stdlib/pull/73)
+  [#96](https://github.com/fortran-lang/stdlib/pull/96)
+  [#139](https://github.com/fortran-lang/stdlib/pull/139)
+- new module `stdlib_quadrature`
+  - new procedures `trapz`, `trapz_weights`, `simps` and `simps_weights`
+    [#146](https://github.com/fortran-lang/stdlib/pull/146)
+  - new procedures `gauss_legendre`, `gauss_legendre_lobatto`
+    [#313](https://github.com/fortran-lang/stdlib/pull/313)
+- new module `stdlib_sorting`
+  - new procedures `sort`, `ord_sort` and `sort_index`
+    [#408](https://github.com/fortran-lang/stdlib/pull/408)
+- new module `stdlib_specialfunctions`
+  - new procedures `legendre` and `dlegendre`
+    [#313](https://github.com/fortran-lang/stdlib/pull/313)
+- new module `stdlib_stats`
+  - new procedure `mean`
+    [#124](https://github.com/fortran-lang/stdlib/pull/124)
+    [#130](https://github.com/fortran-lang/stdlib/pull/130)
+    [#132](https://github.com/fortran-lang/stdlib/pull/132)
+  - new procedure `var`
+    [#144](https://github.com/fortran-lang/stdlib/pull/144)
+  - new procedure `moment`
+    [#153](https://github.com/fortran-lang/stdlib/pull/153)
+  - new procedure `corr`
+    [#191](https://github.com/fortran-lang/stdlib/pull/191)
+  - new procedure `median`
+    [#426](https://github.com/fortran-lang/stdlib/pull/426)
+- new module `stdlib_stats_distribution_PRNG`
+  [#271](https://github.com/fortran-lang/stdlib/pull/271)
+- new module `stdlib_string_type`
+  - new derived types `string_type`
+    [#320](https://github.com/fortran-lang/stdlib/pull/320)
+  - new procedure `move`
+    [#467](https://github.com/fortran-lang/stdlib/pull/467)
+- new module `stdlib_stringlist_type`
+  - new derived types `stringlist_type` and `stringlist_index_type`
+    [#470](https://github.com/fortran-lang/stdlib/pull/470)
+- new module `stdlib_strings`
+  - new procedure `to_string`
+    [#444](https://github.com/fortran-lang/stdlib/pull/444)
+  - new procedures `strip` and `chomp`
+    [#343](https://github.com/fortran-lang/stdlib/pull/343)
+  - new procedures `starts_with` and `ends_with`
+    [#384](https://github.com/fortran-lang/stdlib/pull/384)
+  - new procedure `slice`
+    [#414](https://github.com/fortran-lang/stdlib/pull/414)
+  - new procedure `find`
+    [#433](https://github.com/fortran-lang/stdlib/pull/433)
+  - new procedure `replace_all`
+    [#436](https://github.com/fortran-lang/stdlib/pull/436)
+  - new procedures `padl` and `padr`
+    [#441](https://github.com/fortran-lang/stdlib/pull/441)
+  - new procedure `count`
+    [#453](https://github.com/fortran-lang/stdlib/pull/453)
+- new module `stdlib_system`
+  - new procedure `sleep`
+    [#54](https://github.com/fortran-lang/stdlib/pull/54)

doc/specs/stdlib_math.md

@@ -91,6 +91,51 @@ program demo_clip_real
 end program demo_clip_real
 ```
 
+### `gcd` function
+
+#### Description
+
+Returns the greatest common divisor of two integers.
+
+#### Syntax
+
+`res = [[stdlib_math(module):gcd(interface)]] (a, b)`
+
+#### Status
+
+Experimental
+
+#### Class
+
+Elemental function.
+
+#### Argument(s)
+
+`a`: One integer with `intent(in)` to get the divisor for.
+`b`: Another integer with `intent(in)` to get the divisor for.
+
+Note: All arguments must be integers of the same `kind`.
+
+#### Output value or Result value
+
+Returns an integer of the same `kind` as that of the arguments.
+
+#### Examples
+
+##### Example 1:
+
+```fortran
+program demo_gcd
+  use stdlib_math, only: gcd
+  implicit none
+  integer :: a, b, c
+  
+  a = 48
+  b = 18
+  c = gcd(a, b) ! returns 6
+end program demo_gcd
+```
+
 ### `linspace` - Create a linearly spaced rank one array
 
 #### Description
@@ -342,4 +387,4 @@ program demo_math_arange
     print *, arange(0.0,2.0,0.0)       !! [0.0,1.0,2.0]. Not recommended: `step` argument is zero!
 
 end program demo_math_arange
-```
+```

src/CMakeLists.txt

@@ -67,6 +67,12 @@ set(SRC
 add_library(${PROJECT_NAME} ${SRC})
 
 set(LIB_MOD_DIR ${CMAKE_CURRENT_BINARY_DIR}/mod_files/)
+# We need the module directory before we finish the configure stage since the
+# build interface might resolve before the module directory is generated by CMake
+if(NOT EXISTS "${LIB_MOD_DIR}")
+  make_directory("${LIB_MOD_DIR}")
+endif()
+
 set_target_properties(${PROJECT_NAME} PROPERTIES
     Fortran_MODULE_DIRECTORY ${LIB_MOD_DIR})
 target_include_directories(${PROJECT_NAME} PUBLIC

src/stdlib_math.fypp

@@ -8,7 +8,7 @@ module stdlib_math
 
     implicit none
     private
-    public :: clip, linspace, logspace
+    public :: clip, gcd, linspace, logspace
     public :: EULERS_NUMBER_SP, EULERS_NUMBER_DP, EULERS_NUMBER_QP
     public :: DEFAULT_LINSPACE_LENGTH, DEFAULT_LOGSPACE_BASE, DEFAULT_LOGSPACE_LENGTH
     public :: arange
@@ -28,6 +28,16 @@ module stdlib_math
     #:endfor
     end interface clip
 
+    !> Returns the greatest common divisor of two integers
+    !> ([Specification](../page/specs/stdlib_math.html#gcd))
+    !>
+    !> Version: experimental
+    interface gcd
+    #:for k1, t1 in INT_KINDS_TYPES
+        module procedure gcd_${k1}$
+    #:endfor
+    end interface gcd
+
     interface linspace
     !! Version: Experimental
     !!
@@ -292,4 +302,25 @@ contains
     end function clip_${k1}$
 
     #:endfor
+
+    #:for k1, t1 in INT_KINDS_TYPES
+    !> Returns the greatest common divisor of two integers of kind ${k1}$
+    !> using the Euclidean algorithm.
+    elemental function gcd_${k1}$(a, b) result(res)
+        ${t1}$, intent(in) :: a
+        ${t1}$, intent(in) :: b
+        ${t1}$ :: res
+
+        ${t1}$ :: rem, tmp
+
+        rem = min(abs(a), abs(b))
+        res = max(abs(a), abs(b))
+        do while (rem /= 0_${k1}$)
+          tmp = rem
+          rem = mod(res, rem)
+          res = tmp
+        end do
+    end function gcd_${k1}$
+
+    #:endfor
 end module stdlib_math

src/stdlib_string_type.fypp

@@ -1082,7 +1082,7 @@ contains
         type(string_type), intent(in) :: rhs
         type(string_type) :: string
 
-        string%raw = maybe(rhs) // maybe(lhs)
+        string%raw = maybe(lhs) // maybe(rhs)
 
     end function concat_string_string
 

src/tests/math/test_stdlib_math.f90

@@ -1,7 +1,7 @@
 ! SPDX-Identifier: MIT
 
 program test_stdlib_math
-    use stdlib_math, only: clip
+    use stdlib_math, only: clip, gcd
     use stdlib_error, only: check
     use stdlib_kinds, only: int8, int16, int32, int64, sp, dp, qp
     implicit none
@@ -95,4 +95,23 @@ program test_stdlib_math
     call check(clip(-55891546.2_qp, -689712245.23_qp, -8958133457.23_qp) == -689712245.23_qp, &
                'clip_qp failed for invalid case', warn=.true.)
 
+
+    ! gcd function
+    ! testing format: check(gcd(a, b) == correct answer)
+    call check(gcd(0, 0) == 0, 'gcd(0, 0) failed.', warn=.true.)
+    call check(gcd(2, 0) == 2, 'gcd(2, 0) failed.', warn=.true.)
+    call check(gcd(0, -2) == 2, 'gcd(0, -2) failed.', warn=.true.)
+    call check(gcd(3, 3) == 3, 'gcd(3, 3) failed.', warn=.true.)
+    call check(gcd(9, 6) == 3, 'gcd(9, 6) failed.', warn=.true.)
+    call check(gcd(6, 9) == 3, 'gcd(6, 9) failed.', warn=.true.)
+    call check(gcd(-9, 6) == 3, 'gcd(-9, 6) failed.', warn=.true.)
+    call check(gcd(9, -6) == 3, 'gcd(9, -6) failed.', warn=.true.)
+    call check(gcd(-9, -6) == 3, 'gcd(-9, -6) failed.', warn=.true.)
+    call check(gcd(97, 91) == 1, 'gcd(97, 91) failed.', warn=.true.)
+
+    call check(gcd(48_int8, 18_int8) == 6_int8, 'gcd(48, 18) failed for int8.', warn=.true.)
+    call check(gcd(48_int16, 18_int16) == 6_int16, 'gcd(48, 18) failed for int16', warn=.true.)
+    call check(gcd(48_int32, 18_int32) == 6_int32, 'gcd(48, 18) failed for int32', warn=.true.)
+    call check(gcd(48_int64, 18_int64) == 6_int64, 'gcd(48, 18) failed for int64', warn=.true.)
+
 end program test_stdlib_math

src/tests/string/test_string_operator.f90

@@ -99,11 +99,15 @@ subroutine test_ne
     end subroutine test_ne
 
     subroutine test_concat
-        type(string_type) :: string
-
-        string = "Hello, "
-        string = string // "World!"
-        call check(len(string) == 13)
+        type(string_type) :: a, b
+
+        a = "a"
+        b = "b"
+        call check( "a" //  b  == "ab" )
+        call check( a  // "b" == "ab" )
+        call check( a  //  b  == "ab" )
+        call check( a  //  ""  == "a" )
+        call check( ""  //  b  == "b" )
     end subroutine test_concat
 
 end module test_string_operator