Add compilation of `display` primitive

4 files changed, 44 insertions, 32 deletions

diff --git a/src/compiler.h b/src/compiler.h
index 76d6ccf..18e8a3e 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -139,6 +139,12 @@ compile_type_predicate(OpType op, Object* args) {
     printf("    ;; <-- compile_type_predicate\n");
 }
 
+
+// TODO: Next -> numerical comparison operators =, <=, ...
+// "=", "<", ">", "<=", ">=",
+// "not", "and", "or",
+// NOTE: Make sure to stop evaluating if the condition is not met.
+
 void
 compile_arithmetic_list(OpType op, Object* args) {
     printf("    ;; --> compile_arithmetic_list\n");
@@ -183,6 +189,11 @@ compile_proc_call(Object *obj) {
     if (sv_equal(&obj->head->text, &STRING("bool?"))) {
         compile_type_predicate(OP_IS_BOOL, obj->tail);
     }
+    if (sv_equal(&obj->head->text, &STRING("display"))) {
+        compile_object(obj->tail->head);
+        printf("    pop     rdi\n");
+        printf("    call    display\n");
+    }
 }
 
 void
@@ -199,6 +210,14 @@ compile_object(Object *obj) {
 
 void
 compile(Root *roots) {
+    printf("%%define NIL_VAL      %d\n", NIL_VAL);
+    printf("%%define BOOL_MASK    %d\n", BOOL_MASK);
+    printf("%%define BOOL_TAG     %d\n", BOOL_TAG);
+    printf("%%define BOOL_SHIFT   %d\n", BOOL_SHIFT);
+    printf("%%define FIXNUM_MASK  %d\n", FIXNUM_MASK);
+    printf("%%define FIXNUM_TAG   %d\n", FIXNUM_TAG);
+    printf("%%define FIXNUM_SHIFT %d\n", FIXNUM_SHIFT);
+    printf("\n");
     emit_file(PRELUDE_FILE);
     for (size_t i = 0; i < array_size(roots); i++) {
         Object *root = roots[i];
diff --git a/src/parser.c b/src/parser.c
index 86cf713..9191aa2 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -10,6 +10,7 @@ static char *builtins [] = {
     "=", "<", ">", "<=", ">=",
     "not", "and", "or",
     "nil?", "zero?", "fixnum?", "bool?",
+    "display",
 };
 
 uint64_t
@@ -597,6 +598,8 @@ parse(Token *tokens, Errors *errors) {
     array_free(roots);
     roots = final_roots;
 
+    // TODO: Check if primitive procedures have been given the right number of
+    // arguments.
     // TODO: Type check basic expressions (e.g. arithmetic/numeric comparisons).
     // We can't be sure when we have functions unless the return type is known.
 
diff --git a/src/x86_64/postlude.asm b/src/x86_64/postlude.asm
index 5c8e56f..3355286 100644
--- a/src/x86_64/postlude.asm
+++ b/src/x86_64/postlude.asm
@@ -2,29 +2,7 @@
 _start_return:
     ;; return the last value in the stack
     pop     rdi
-
-    ;; is nil?
-    mov     rax, rdi
-    cmp     rax, NIL_VAL
-    je      exit
-
-    ;; is boolean?
-    mov     rax, rdi
-    and     rax, BOOL_MASK
-    cmp     rax, BOOL_TAG
-    jne     not_bool
-    call    printbool
-    jmp     exit
-not_bool:
-
-    ;; is fixnum?
-    mov     rax, rdi
-    and     rax, FIXNUM_MASK
-    cmp     rax, FIXNUM_TAG
-    jne     not_fixnum
-    call    printdln
-    jmp     exit
-not_fixnum:
+    call    display
 
 exit:
     ; exit syscall
diff --git a/src/x86_64/prelude.asm b/src/x86_64/prelude.asm
index c314ba4..6bb6627 100644
--- a/src/x86_64/prelude.asm
+++ b/src/x86_64/prelude.asm
@@ -1,12 +1,3 @@
-;; Value types.
-%define NIL_VAL      1
-%define BOOL_MASK    3
-%define BOOL_TAG     3
-%define BOOL_SHIFT   2
-%define FIXNUM_MASK  1
-%define FIXNUM_TAG   0
-%define FIXNUM_SHIFT 1
-
 printdln:
     sar     rdi, FIXNUM_SHIFT
     sub     rsp, 40
@@ -84,6 +75,27 @@ true_str:
 false_str:
     db      "false", 10
 
+display:
+    ;; is nil?
+    mov     rax, rdi
+    cmp     rax, NIL_VAL
+    je      display_end
+
+    ; ;; is boolean?
+    mov     rax, rdi
+    and     rax, BOOL_MASK
+    cmp     rax, BOOL_TAG
+    jne     not_bool
+    call    printbool
+    ret
+not_bool:
+
+    ;; is fixnum?
+    mov     rax, rdi
+    call    printdln
+display_end:
+    ret
+
 global  _start
 _start:
     push NIL_VAL