Create Scheme implementation

I expected it to be similar to the common lisp implementation, but it's
actually closer tothe OCaml one.

README.md

@@ -52,6 +52,7 @@ At the current moment, I've implemented it in the following languages:
 * Ruby
 * Rust
 * Scala
+* Scheme
 * Shell Script (should work in any POSIX shell)
 * TypeScript *(lightly tweaked JavaScript implementation)* (via ts-node)
 * Vala

RUNNERS/common.sh

@@ -17,8 +17,8 @@
 colortest_implementations=(
     algol_68 awk babalang befunge bf c cobol cpp csharp d erlang fender forth
     fortran go haskell java javascript kotlin lisp lua nim objective-c ocaml
-    octave odin pascal perl php powershell python r rockstar ruby rust scala sh
-    typescript vala x86-64_linux_asm zig
+    octave odin pascal perl php powershell python r rockstar ruby rust scala
+    scheme sh typescript vala x86-64_linux_asm zig
 )
 
 basedir="$(dirname "$(realpath "${BASH_SOURCE[0]}")")"

RUNNERS/install-deps.sh

@@ -45,6 +45,7 @@ python_dependencies() { apt_wrapper python3 python3; }
 r_dependencies() { apt_wrapper r r-cran-littler; }
 ruby_dependencies() { apt_wrapper ruby ruby; }
 scala_dependencies() { apt_wrapper scalac scala; }
+scheme_dependencies() { apt_wrapper csi chicken-bin; }
 typescript_dependencies() { apt_wrapper ts-node ts-node; }
 vala_dependencies() { apt_wrapper valac valac;}
 

RUNNERS/run-version.sh

@@ -50,6 +50,7 @@ run_version() {
         'r')          r colortest.r                   ;;
         'rockstar')   satriani-wrapper colortest.rock ;;
         'ruby')       ruby colortest.rb               ;;
+        'scheme')     csi -script colortest.sld       ;;
         'sh')         sh colortest.sh                 ;;
         'typescript') ts-node colortest.ts            ;;
         # GNU Octave throws an error on exit if XDG_DATA_HOME is missing

scheme/colortest.sld

@@ -0,0 +1,42 @@
+; SPDX-FileCopyrightText: 2024 Eli Array Minkoff
+;
+; SPDX-License-Identifier: GPL-3.0-only
+
+
+(define (colorcell n)
+  (display "\x1b[48;5;") (display (number->string n)) (display "m  ")
+)
+
+(define (range lo hi step)
+  ; Return an empty list if step <= 0 or lo >= hi
+  (cond ((<= step 0) '())
+        ((>= lo hi) '())
+      ; return lo combined with the next iteration's output
+        (else (cons lo (range (+ lo step) hi step)))))
+
+; Print the first 16 colors - these vary by terminal configuration
+(newline)
+(map colorcell (range 0 16 1))
+(display "\x1b[0m\n\n")
+
+; Print the 6 sides of the color cube - these are more standardized,
+; but the order is a bit odd, thus the need for this trickery
+(define (row_a n) (range n (+ n 6) 1))
+(define (row_b n) (range (+ n 36) (+ n 42) 1))
+(define (row_c n) (range (+ n 72) (+ n 78) 1))
+(define (part_2_row n)
+  (map colorcell (row_a n))
+  (display "\x1b[0m  ")
+  (map colorcell (row_b n))
+  (display "\x1b[0m  ")
+  (map colorcell (row_c n))
+  (display "\x1b[0m\n"))
+
+(map part_2_row (range 16 52 6))
+(newline)
+(map part_2_row (range 124 160 6))
+(newline)
+
+; Finally, the 24 grays
+(map colorcell (range 232 256 1))
+(display "\x1b[0m\n\n")