Function special form

lisp/kernel.gl

@@ -23,4 +23,4 @@
   (princ datum print-char-fun)
   (funcall (or print-char-fun 'write-byte) ?\n))
 
-(princln '#1=(a '#2=(a #1# c) . #1#))
+(princln '#'princ)

src/base.c

@@ -1,5 +1,6 @@
 #include "base.h"
 
+#include "function.h"
 #include "gc.h"
 #include "hashtable.h"
 #include "lisp.h"
@@ -80,6 +81,16 @@ DEFSPECIAL(quote, "quote", (LispVal * form), "(form)", "") {
     return form;
 }
 
+DEFSPECIAL(function, "function", (LispVal * form), "(form)", "") {
+    if (SYMBOLP(form)) {
+        LispVal *res = Fsymbol_function(form, Qt);
+        if (FUNCTIONP(res) && NILP(Fspecial_form_p(res))) {
+            return res;
+        }
+    }
+    return form;
+}
+
 // ################
 // # Constructors #
 // ################
@@ -208,7 +219,7 @@ DEFINE_SYMBOL(string, "strin");
 DEFINE_SYMBOL(symbol, "symbol");
 // vector defined above
 DEFINE_SYMBOL(hash_table, "hash-table");
-DEFINE_SYMBOL(function, "function");
+// function defind above
 
 LispVal *symbol_for_type(LispValType type) {
     switch (type) {

src/base.h

@@ -360,6 +360,7 @@ static ALWAYS_INLINE bool EQ(LispVal *val1, LispVal *val2) {
 DECLARE_FUNCTION(id, (LispVal * obj));
 DECLARE_FUNCTION(eq, (LispVal * obj1, LispVal *obj2));
 DECLARE_FUNCTION(quote, (LispVal * form));
+DECLARE_FUNCTION(function, (LispVal * form));
 
 // TODO probably move these to another file
 LispVal *make_vector(LispVal **data, size_t length, bool take);

src/print.c

@@ -267,7 +267,8 @@ static void print_numbered_reference(struct PrintContext *restrict pc,
 }
 
 static void print_cons(struct PrintContext *restrict pc, LispVal *val) {
-    if (pc->opts.quoted && EQ(XCAR(val), Qquote) && list_length_eq(val, 2)) {
+    if (pc->opts.quoted && (EQ(XCAR(val), Qquote) || EQ(XCAR(val), Qfunction))
+        && list_length_eq(val, 2)) {
         if (recursive_object_p(pc, val)) {
             if (printed_seen_object_p(pc, val)) {
                 print_numbered_reference(pc, val, '#');
@@ -276,6 +277,9 @@ static void print_cons(struct PrintContext *restrict pc, LispVal *val) {
             print_numbered_reference(pc, val, '=');
             mark_object_printed(pc, val);
         }
+        if (EQ(XCAR(val), Qfunction)) {
+            print_char(pc, '#');
+        }
         print_char(pc, '\'');
         print_driver(pc, SECOND(val));
         return;

src/read.c

@@ -540,13 +540,22 @@ static LispVal *hash_dispatcher(ReadStream *restrict stream) {
     int c;
     while ((c = peek_char(stream)) != READ_EOS) {
         switch (c) {
+        case '\'':
+            pop_char(stream);
+            return UNWIND_AND_RETURN(stack_ref, LIST(Qfunction, read(stream)));
         case '#':
+            if (!ss.nchars) {
+                read_error(stream, "numbered reference without a number");
+            }
             pop_char(stream);
             return UNWIND_AND_RETURN(
                 stack_ref,
                 lookup_numbered_object(
                     stream, convert_object_number(stream, ss.buffer)));
         case '=':
+            if (!ss.nchars) {
+                read_error(stream, "numbered object without a number");
+            }
             pop_char(stream);
             return UNWIND_AND_RETURN(
                 stack_ref, read_numbered(stream, convert_object_number(