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Add LISP interpreter

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Justine Tunney 2022-04-07 20:30:22 -07:00
parent 4f98ad1054
commit d31bebdd2d
84 changed files with 9081 additions and 0 deletions
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68
tool/plinko/lib/findfreevariables.c Normal file
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "tool/plinko/lib/cons.h"
#include "tool/plinko/lib/index.h"
#include "tool/plinko/lib/plinko.h"
/**
* Finds free variables in expression.
*
* @param e is expression
* @param r is atom list result accumulator
* @param s is atom tree of shadowed bindings
* @return atom list of crash bindings without duplicates
* @note this produces garbage when recursing into let
*/
int FindFreeVariables(int e, int r, int s) {
int f, t;
if (e >= 0) {
if (!IsConstant(e) && !HasAtom(e, s) && !HasAtom(e, r)) {
t = GetCommonCons(e, r);
r = t ? t : Cons(e, r);
}
} else {
f = Car(e);
if (f != kQuote && f != kClosure) {
if (f == kLambda || f == kMacro) {
r = FindFreeVariables(Caddr(e), r, Shadow(Cadr(e), s));
} else if (f == kCond) {
while ((e = Cdr(e)) < 0) {
if ((f = Car(e)) < 0) {
r = FindFreeVariables(Car(f), r, s);
if ((f = Cdr(f)) < 0) {
r = FindFreeVariables(Car(f), r, s);
}
}
}
} else {
while (e) {
if (e < 0) {
f = Car(e);
e = Cdr(e);
} else {
f = e;
e = 0;
}
r = FindFreeVariables(f, r, s);
}
}
}
}
return r;
}