From da94105307fb799977a12d9a52149c4a622a589b Mon Sep 17 00:00:00 2001
From: Brandon Rozek <rozekbrandon@gmail.com>
Date: Tue, 12 Jun 2018 19:06:17 -0400
Subject: [PATCH] Implemented and/or

---
 lval/conditionals.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
 lval/conditionals.h |  3 +++
 lval/environment.c  |  7 +++++++
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/lval/conditionals.c b/lval/conditionals.c
index 8333d9f..1dab6bd 100644
--- a/lval/conditionals.c
+++ b/lval/conditionals.c
@@ -1,6 +1,7 @@
 #include "conditionals.h"
 #include "numbers.h"
 #include "operations.h"
+#include "expressions.h"
 #include "error.h"
 
 lval* builtin_gt(lenv* e, lval* a) {
@@ -97,6 +98,17 @@ lval* builtin_cmp(lenv* e, lval* a, char* op) {
     if (strcmp(op, "!=") == 0) {
         r = !lval_eq(a->cell[0], a->cell[1]);
     }
+    if (strcmp(op, "or") == 0) {
+        LASSERT_TYPE("or", a, 0, LVAL_LONG)
+        LASSERT_TYPE("or", a, 1, LVAL_LONG)
+        r = (a->cell[0]->data.num || a->cell[1]->data.num);
+    }
+    if (strcmp(op, "and") == 0) {
+        LASSERT_TYPE("and", a, 0, LVAL_LONG)
+        LASSERT_TYPE("and", a, 1, LVAL_LONG)
+        r = (a->cell[0]->data.num && a->cell[1]->data.num);
+    }
+
     lval_del(a);
     return lval_long(r);
 }
@@ -107,4 +119,33 @@ lval* builtin_eq(lenv* e, lval* a) {
 
 lval* builtin_ne(lenv* e, lval* a) {
     return builtin_cmp(e, a, "!=");
-}
\ No newline at end of file
+}
+lval* builtin_or(lenv* e, lval* a) {
+    return builtin_cmp(e, a, "or");
+}
+
+lval* builtin_and(lenv* e, lval* a) {
+    return builtin_cmp(e, a, "and");
+}
+
+lval* builtin_if(lenv* e, lval* a) {
+    LASSERT_NUM("if", a, 3)
+    LASSERT_TYPE("if", a, 0, LVAL_LONG)
+    LASSERT_TYPE("if", a, 1, LVAL_QEXPR)
+    LASSERT_TYPE("if", a, 2, LVAL_QEXPR)
+
+    // Mark both expressions as evaluable
+    lval* x;
+    a->cell[1]->type = LVAL_SEXPR;
+    a->cell[2]->type = LVAL_SEXPR;
+
+    if (a->cell[0]->data.num) {
+        x = lval_eval(e, lval_pop(a, 1));
+    } else {
+        x = lval_eval(e, lval_pop(a, 2));
+    }
+
+    // Delete the argument list and return
+    lval_del(a);
+    return x;
+}
diff --git a/lval/conditionals.h b/lval/conditionals.h
index 2db2046..b49ba16 100644
--- a/lval/conditionals.h
+++ b/lval/conditionals.h
@@ -15,5 +15,8 @@ lval* builtin_cmp(lenv* e, lval* a, char* op);
 lval* builtin_eq(lenv* e, lval* a);
 lval* builtin_ne(lenv* e, lval* a);
 
+lval* builtin_if(lenv* e, lval* a);
+lval* builtin_and(lenv* e, lval* a);
+lval* builtin_or(lenv* e, lval* a);
 
 #endif
diff --git a/lval/environment.c b/lval/environment.c
index 04c5eba..0691a7f 100644
--- a/lval/environment.c
+++ b/lval/environment.c
@@ -136,6 +136,13 @@ void lenv_add_builtins(lenv* e) {
     lenv_add_builtin(e, "==", builtin_eq);
     lenv_add_builtin(e, "!=", builtin_ne);
 
+    lenv_add_builtin(e, "if", builtin_if);
+
+    lenv_add_builtin(e, "and", builtin_and);
+    lenv_add_builtin(e, "&&", builtin_and);
+    lenv_add_builtin(e, "or", builtin_or);
+    lenv_add_builtin(e, "||", builtin_or);
+
 }
 
 lval* builtin_ls(lenv* e, lval* a) {