init

README.md

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+# Interscheme
+
+A pixel graphics and sound playground using SDL2 and chibi-scheme.
+
+WIP.
+
+See also: http://synthcode.com/scheme/chibi/#h3_QuickStart
+
+## Build
+
+First, build and install chibi-scheme:
+
+```
+git clone https://github.com/ashinn/chibi-scheme.git
+cd chibi-scheme
+make -j$(nproc)
+sudo make install
+```
+
+This will yield `libchibi-scheme.so` in `/usr/local/lib` and `/usr/local/include/chibi` header files. You might need to do `ldconfig /usr/local/lib` once.
+
+It will also make a scheme REPL called `chibi-scheme`.
+
+Then, in this here repo:
+
+```
+./build.sh
+```
+
+## Run
+
+Edit `init.scm` to your liking.
+
+```
+./interscheme
+```

build.sh

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+gcc -o interscheme interscheme.c -lchibi-scheme
+

init.scm

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+(define (sierpinski n)
+  (for-each
+   (lambda (x) (display (list->string (append x (list #\return)))))
+   (let loop ((acc (list (list #\*))) (spaces (list #\ )) (n n))
+     (if (zero? n)
+         acc
+         (loop
+          (append
+           (map (lambda (x) (append spaces x spaces)) acc)
+           (map (lambda (x) (append x (list #\ ) x)) acc))
+          (append spaces spaces)
+          (- n 1))))))

interscheme.c

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+#include <stdio.h>
+#include <chibi/sexp.h>
+
+void dostuff(sexp ctx) {
+  /* declare and preserve local variables */
+  sexp_gc_var2(obj1, obj2);
+  sexp_gc_preserve2(ctx, obj1, obj2);
+
+  /* load a file containing Scheme code */
+  obj1 = sexp_c_string(ctx, "./init.scm", -1);
+  sexp_load(ctx, obj1, NULL);
+
+  /* eval a C string as Scheme code */
+  sexp_eval_string(ctx, "(sierpinski 7)", -1, NULL);
+
+  /* construct a Scheme expression to eval */
+  obj1 = sexp_intern(ctx, "my-procedure", -1);
+  obj2 = sexp_cons(ctx, obj1, SEXP_NULL);
+  sexp_eval(ctx, obj2, NULL);
+
+  /* release the local variables */
+  sexp_gc_release2(ctx);
+}
+
+int main(int argc, char** argv) {
+  sexp ctx;
+  sexp_scheme_init();
+  ctx = sexp_make_eval_context(NULL, NULL, NULL, 0, 0);
+  sexp_load_standard_env(ctx, NULL, SEXP_SEVEN);
+  sexp_load_standard_ports(ctx, NULL, stdin, stdout, stderr, 1);
+  dostuff(ctx);
+  sexp_destroy_context(ctx);
+}