altos/lisp: Add quasiquote

[fw/altos] / src / lisp / ao_lisp_read.c

diff --git a/src/lisp/ao_lisp_read.c b/src/lisp/ao_lisp_read.c
index c5a238cc5513132bbbda6107173995d3335e3dfa..747963ab632b3cdba14d67930c8419b875c8c570 100644 (file)
--- a/src/lisp/ao_lisp_read.c
+++ b/src/lisp/ao_lisp_read.c
@@ -61,7 +61,7 @@ static const uint16_t lex_classes[128] = {
        PRINTABLE|SPECIAL,      /* ) */
        PRINTABLE,              /* * */
        PRINTABLE|SIGN,         /* + */
-       PRINTABLE,              /* , */
+       PRINTABLE|SPECIAL,      /* , */
        PRINTABLE|SIGN,         /* - */
        PRINTABLE|DOTC|FLOATC,  /* . */
        PRINTABLE,              /* / */
@@ -113,7 +113,7 @@ static const uint16_t       lex_classes[128] = {
        PRINTABLE,              /*  ] */
        PRINTABLE,              /*  ^ */
        PRINTABLE,              /*  _ */
-       PRINTABLE,              /*  ` */
+       PRINTABLE|SPECIAL,      /*  ` */
        PRINTABLE,              /*  a */
        PRINTABLE,              /*  b */
        PRINTABLE,              /*  c */
@@ -314,6 +314,18 @@ _lex(void)
                                return QUOTE;
                        case '.':
                                return DOT;
+                       case '`':
+                               return QUASIQUOTE;
+                       case ',':
+                               c = lexc();
+                               if (c == '@') {
+                                       add_token(c);
+                                       end_token();
+                                       return UNQUOTE_SPLICING;
+                               } else {
+                                       lex_unget(c);
+                                       return UNQUOTE;
+                               }
                        }
                }
                if (lex_class & POUND) {
@@ -562,11 +574,27 @@ ao_lisp_read(void)
                                v = AO_LISP_NIL;
                        break;
                case QUOTE:
+               case QUASIQUOTE:
+               case UNQUOTE:
+               case UNQUOTE_SPLICING:
                        if (!push_read_stack(cons, read_state))
                                return AO_LISP_NIL;
                        cons++;
                        read_state = READ_IN_QUOTE;
-                       v = _ao_lisp_atom_quote;
+                       switch (parse_token) {
+                       case QUOTE:
+                               v = _ao_lisp_atom_quote;
+                               break;
+                       case QUASIQUOTE:
+                               v = _ao_lisp_atom_quasiquote;
+                               break;
+                       case UNQUOTE:
+                               v = _ao_lisp_atom_unquote;
+                               break;
+                       case UNQUOTE_SPLICING:
+                               v = _ao_lisp_atom_unquote2dsplicing;
+                               break;
+                       }
                        break;
                case CLOSE:
                        if (!cons) {