Added boolean type

Author: lastcraft

atoms.c

@@ -3,18 +3,35 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
+#include <stdbool.h>
 
+static void boolean_writer(void *, Printf);
 static void number_writer(void *, Printf);
 static void identifier_writer(void *, Printf);
 static void string_writer(void *, Printf);
 static long last(char *);
 
 void declare_atoms(void) {
+    boolean_type = declare(free, boolean_writer);
     number_type = declare(free, number_writer);
     identifier_type = declare(free, identifier_writer);
     string_type = declare(free, string_writer);
 }
 
+Object *boolean(bool true_or_false) {
+    bool *cell = (bool *)malloc(sizeof(bool));
+    *cell = true_or_false;
+    return wrap(boolean_type, cell);
+}
+
+int is_boolean(Object *boolean) {
+    return is_a(boolean_type, boolean);
+}
+
+static void boolean_writer(void *boolean, Printf printer) {
+    printer("%s", *(bool *)boolean == true ? "true" : "false");
+}
+
 Object *number(long number) {
     long *cell = (long *)malloc(sizeof(long));
     *cell = number;

atoms.h

@@ -1,13 +1,17 @@
 #ifndef ATOMS_HEADER
 #define ATOMS_HEADER
 
+#include <stdbool.h>
 #include "type.h"
 
+Type *boolean_type;
 Type *number_type;
 Type *identifier_type;
 Type *string_type;
 
 void declare_atoms(void);
+Object *boolean(bool);
+int is_boolean(Object *);
 Object *number(long);
 int is_number(Object *);
 Object *identifier(char *);

function.c

@@ -14,10 +14,11 @@ struct Lambda_ {
 
 static void built_in_writer(void *, Printf);
 static void lambda_writer(void *, Printf);
+static void destroy_lambda(void *);
 
 void declare_functions(void) {
     built_in_type = declare(free, built_in_writer);
-    lambda_type = declare(free, lambda_writer);
+    lambda_type = declare(destroy_lambda, lambda_writer);
 }
 
 Object *built_in(Callable code) {
@@ -39,14 +40,14 @@ Callable code(BuiltIn *built_in) {
     return built_in->code;
 }
 
-Object *body(Object *function) {
-    return ((Lambda *)value(function))->body;
-}
-
 Object *parameters(Object *function) {
     return ((Lambda *)value(function))->parameters;
 }
 
+Object *body(Object *function) {
+    return ((Lambda *)value(function))->body;
+}
+
 Object *special_form(Object *function) {
     if (is_built_in(function)) {
         ((BuiltIn *)value(function))->special_form = 1;
@@ -87,3 +88,9 @@ static void lambda_writer(void *lambda, Printf printer) {
     write_object(((Lambda *)lambda)->body, printer);
     printer(">");
 }
+
+static void destroy_lambda(void *lambda) {
+    destroy(((Lambda *)lambda)->parameters);
+    destroy(((Lambda *)lambda)->body);
+    free(lambda);
+}

function.h

@@ -15,8 +15,8 @@ void declare_functions(void);
 Object *built_in(Callable);
 Object *lambda(Object *, Object *);
 Callable code(BuiltIn *built_in);
-Object *body(Object *);
 Object *parameters(Object *);
+Object *body(Object *);
 Object *special_form(Object *);
 int is_function(Object *);
 int is_special_form(Object *);

parser.l

@@ -1,5 +1,6 @@
 %{
 
+#include <stdbool.h>
 #include "y.tab.h"
 
 %}
@@ -10,6 +11,16 @@
     return NIL;
 }
 
+true {
+    yylval.b = true;
+    return BOOLEAN;
+}
+
+false {
+    yylval.b = false;
+    return BOOLEAN;
+}
+
 [0-9]+ {
     yylval.l = atoi(yytext);
     return NUMBER;

parser.y

@@ -7,6 +7,7 @@
 #include "stack.h"
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdbool.h>
 
 Stack *input = NULL;
 
@@ -52,11 +53,13 @@ static Object *pour_stack_into_list(Object *list, Stack *stack) {
 %}
 
 %token NIL
+%token <b> BOOLEAN
 %token <l> NUMBER
 %token <s> IDENTIFIER
 %token <s> QUOTED_STRING
 
 %union {
+    bool b;
     long l;
     char *s;
 }
@@ -102,7 +105,10 @@ elements: element | elements element;
 element: atom
     | list;
 
-atom: NUMBER {
+atom: BOOLEAN {
+        push((Stack *)peek(input), (void *)boolean($1));
+    }
+    | NUMBER {
         push((Stack *)peek(input), (void *)number($1));
     }
     | IDENTIFIER {