Add LISP interpreter

tool/plinko/lib/tree.h

@@ -0,0 +1,47 @@
+#ifndef COSMOPOLITAN_TOOL_PLINKO_LIB_TREE_H_
+#define COSMOPOLITAN_TOOL_PLINKO_LIB_TREE_H_
+#include "tool/plinko/lib/cons.h"
+#include "tool/plinko/lib/plinko.h"
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+int PutTree(int, int, int);
+int GetTree(int, int);
+int GetTreeCount(int, int, int *);
+int Nod(int, int, int, int);
+
+forceinline pureconst int Key(int E) {
+  return E < 0 ? Car(E) : E;
+}
+
+forceinline pureconst int Val(int E) {
+  return E < 0 ? Cdr(E) : E;
+}
+
+forceinline pureconst int Ent(int N) {
+  return Car(Car(N));
+}
+
+forceinline pureconst int Chl(int N) {
+  return Cdr(Car(N));
+}
+
+forceinline pureconst int Lit(int N) {
+  return Car(Chl(N));
+}
+
+forceinline pureconst int Rit(int N) {
+  return Cdr(Chl(N));
+}
+
+forceinline pureconst int Red(int N) {
+  return Cdr(N);
+}
+
+forceinline int Bkn(int N) {
+  return Red(N) ? Cons(Car(N), 0) : N;
+}
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_TOOL_PLINKO_LIB_TREE_H_ */