altos/lisp: Add apply
[fw/altos] / src / lisp / ao_lisp_read.c
index ccb4ba3a896deacfacb0f00b361489700fb264d6..8c06e19898f93c2300e60711396063f1666eb50a 100644 (file)
@@ -51,18 +51,18 @@ static const uint16_t       lex_classes[128] = {
        PRINTABLE|WHITE,        /*    */
        PRINTABLE,              /* ! */
        PRINTABLE|STRINGC,      /* " */
-       PRINTABLE|COMMENT,      /* # */
+       PRINTABLE|POUND,        /* # */
        PRINTABLE,              /* $ */
        PRINTABLE,              /* % */
        PRINTABLE,              /* & */
-       PRINTABLE|QUOTEC,       /* ' */
-       PRINTABLE|BRA,          /* ( */
-       PRINTABLE|KET,          /* ) */
+       PRINTABLE|SPECIAL,      /* ' */
+       PRINTABLE|SPECIAL,      /* ( */
+       PRINTABLE|SPECIAL,      /* ) */
        PRINTABLE,              /* * */
        PRINTABLE|SIGN,         /* + */
        PRINTABLE,              /* , */
        PRINTABLE|SIGN,         /* - */
-       PRINTABLE,              /* . */
+       PRINTABLE|SPECIAL,      /* . */
        PRINTABLE,              /* / */
        PRINTABLE|DIGIT,        /* 0 */
        PRINTABLE|DIGIT,        /* 1 */
@@ -142,7 +142,7 @@ static const uint16_t       lex_classes[128] = {
        PRINTABLE,              /*  { */
        PRINTABLE|VBAR,         /*  | */
        PRINTABLE,              /*  } */
-       PRINTABLE|TWIDDLE,      /*  ~ */
+       PRINTABLE,              /*  ~ */
        IGNORE,                 /*  ^? */
 };
 
@@ -155,8 +155,9 @@ lex_get()
        if (lex_unget_c) {
                c = lex_unget_c;
                lex_unget_c = 0;
-       } else
-               c = getchar();
+       } else {
+               c = ao_lisp_getc();
+       }
        return c;
 }
 
@@ -167,18 +168,38 @@ lex_unget(int c)
                lex_unget_c = c;
 }
 
+static uint16_t        lex_class;
+
+static int
+lexc(void)
+{
+       int     c;
+       do {
+               c = lex_get();
+               if (c == EOF) {
+                       c = 0;
+                       lex_class = ENDOFFILE;
+               } else {
+                       c &= 0x7f;
+                       lex_class = lex_classes[c];
+               }
+       } while (lex_class & IGNORE);
+       return c;
+}
+
 static int
-lex_quoted (void)
+lex_quoted(void)
 {
        int     c;
        int     v;
        int     count;
 
        c = lex_get();
-//     if (jumping)
-//             return nil;
-       if (c == EOF)
-               return EOF;
+       if (c == EOF) {
+               lex_class = ENDOFFILE;
+               return 0;
+       }
+       lex_class = 0;
        c &= 0x7f;
        switch (c) {
        case 'n':
@@ -205,8 +226,6 @@ lex_quoted (void)
                count = 1;
                while (count <= 3) {
                        c = lex_get();
-//                     if (jumping)
-//                             return nil;
                        if (c == EOF)
                                return EOF;
                        c &= 0x7f;
@@ -223,32 +242,6 @@ lex_quoted (void)
        }
 }
 
-static uint16_t        lex_class;
-
-static int
-lexc(void)
-{
-       int     c;
-       do {
-               c = lex_get();
-               if (c == EOF) {
-                       lex_class = ENDOFFILE;
-                       c = 0;
-               } else {
-                       c &= 0x7f;
-                       lex_class = lex_classes[c];
-                       if (lex_class & BACKSLASH) {
-                               c = lex_quoted();
-                               if (c == EOF)
-                                       lex_class = ENDOFFILE;
-                               else
-                                       lex_class = PRINTABLE;
-                       }
-               }
-       } while (lex_class & IGNORE);
-       return c;
-}
-
 #define AO_LISP_TOKEN_MAX      32
 
 static char    token_string[AO_LISP_TOKEN_MAX];
@@ -265,7 +258,7 @@ static inline void end_token(void) {
 }
 
 static int
-lex(void)
+_lex(void)
 {
        int     c;
 
@@ -273,34 +266,89 @@ lex(void)
        for (;;) {
                c = lexc();
                if (lex_class & ENDOFFILE)
-                       return AO_LISP_NIL;
+                       return END;
 
-//             if (jumping)
-//                     return nil;
                if (lex_class & WHITE)
                        continue;
 
-               if (lex_class & (BRA|KET|QUOTEC)) {
+               if (lex_class & COMMENT) {
+                       while ((c = lexc()) != '\n') {
+                               if (lex_class & ENDOFFILE)
+                                       return END;
+                       }
+                       continue;
+               }
+
+               if (lex_class & SPECIAL) {
                        add_token(c);
                        end_token();
                        switch (c) {
                        case '(':
+                       case '[':
                                return OPEN;
                        case ')':
+                       case ']':
                                return CLOSE;
                        case '\'':
                                return QUOTE;
+                       case '.':
+                               return DOT;
                        }
                }
-               if (lex_class & TWIDDLE) {
-                       token_int = lexc();
-                       return NUM;
+               if (lex_class & POUND) {
+                       c = lexc();
+                       switch (c) {
+                       case 't':
+                               add_token(c);
+                               end_token();
+                               return BOOL;
+                       case 'f':
+                               add_token(c);
+                               end_token();
+                               return BOOL;
+                       case '\\':
+                               for (;;) {
+                                       int alphabetic;
+                                       c = lexc();
+                                       alphabetic = (('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'));
+                                       if (token_len == 0) {
+                                               add_token(c);
+                                               if (!alphabetic)
+                                                       break;
+                                       } else {
+                                               if (alphabetic)
+                                                       add_token(c);
+                                               else {
+                                                       lex_unget(c);
+                                                       break;
+                                               }
+                                       }
+                               }
+                               end_token();
+                               if (token_len == 1)
+                                       token_int = token_string[0];
+                               else if (!strcmp(token_string, "space"))
+                                       token_int = ' ';
+                               else if (!strcmp(token_string, "newline"))
+                                       token_int = '\n';
+                               else if (!strcmp(token_string, "tab"))
+                                       token_int = '\t';
+                               else if (!strcmp(token_string, "return"))
+                                       token_int = '\r';
+                               else if (!strcmp(token_string, "formfeed"))
+                                       token_int = '\f';
+                               else {
+                                       ao_lisp_error(AO_LISP_INVALID, "invalid character token #\\%s", token_string);
+                                       continue;
+                               }
+                               return NUM;
+                       }
                }
                if (lex_class & STRINGC) {
                        for (;;) {
                                c = lexc();
-//                             if (jumping)
-//                                     return nil;
+                               if (lex_class & BACKSLASH)
+                                       c = lex_quoted();
                                if (lex_class & (STRINGC|ENDOFFILE)) {
                                        end_token();
                                        return STRING;
@@ -336,8 +384,6 @@ lex(void)
                                }
                                add_token (c);
                                c = lexc ();
-//                             if (jumping)
-//                                     return nil;
                                if (lex_class & (NOTNAME)) {
 //                                     if (lex_class & ENDOFFILE)
 //                                             clearerr (f);
@@ -356,41 +402,92 @@ lex(void)
        }
 }
 
+static inline int lex(void)
+{
+       int     parse_token = _lex();
+       DBGI("token %d (%s)\n", parse_token, token_string);
+       return parse_token;
+}
+
 static int parse_token;
-static uint8_t                 been_here;
-static struct ao_lisp_cons     *read_cons;
-static struct ao_lisp_cons     *read_cons_tail;
-static struct ao_lisp_cons     *read_stack;
 
-static ao_lisp_poly
-read_item(void)
+struct ao_lisp_cons    *ao_lisp_read_cons;
+struct ao_lisp_cons    *ao_lisp_read_cons_tail;
+struct ao_lisp_cons    *ao_lisp_read_stack;
+
+#define READ_IN_QUOTE  0x01
+#define READ_SAW_DOT   0x02
+#define READ_DONE_DOT  0x04
+
+static int
+push_read_stack(int cons, int read_state)
+{
+       DBGI("push read stack %p 0x%x\n", ao_lisp_read_cons, read_state);
+       DBG_IN();
+       if (cons) {
+               ao_lisp_read_stack = ao_lisp_cons_cons(ao_lisp_cons_poly(ao_lisp_read_cons),
+                                                      ao_lisp__cons(ao_lisp_int_poly(read_state),
+                                                                    ao_lisp_cons_poly(ao_lisp_read_stack)));
+               if (!ao_lisp_read_stack)
+                       return 0;
+       }
+       ao_lisp_read_cons = NULL;
+       ao_lisp_read_cons_tail = NULL;
+       return 1;
+}
+
+static int
+pop_read_stack(int cons)
+{
+       int     read_state = 0;
+       if (cons) {
+               ao_lisp_read_cons = ao_lisp_poly_cons(ao_lisp_read_stack->car);
+               ao_lisp_read_stack = ao_lisp_poly_cons(ao_lisp_read_stack->cdr);
+               read_state = ao_lisp_poly_int(ao_lisp_read_stack->car);
+               ao_lisp_read_stack = ao_lisp_poly_cons(ao_lisp_read_stack->cdr);
+               for (ao_lisp_read_cons_tail = ao_lisp_read_cons;
+                    ao_lisp_read_cons_tail && ao_lisp_read_cons_tail->cdr;
+                    ao_lisp_read_cons_tail = ao_lisp_poly_cons(ao_lisp_read_cons_tail->cdr))
+                       ;
+       } else {
+               ao_lisp_read_cons = 0;
+               ao_lisp_read_cons_tail = 0;
+               ao_lisp_read_stack = 0;
+       }
+       DBG_OUT();
+       DBGI("pop read stack %p %d\n", ao_lisp_read_cons, read_state);
+       return read_state;
+}
+
+ao_poly
+ao_lisp_read(void)
 {
        struct ao_lisp_atom     *atom;
        char                    *string;
        int                     cons;
-       ao_lisp_poly            v;
+       int                     read_state;
+       ao_poly                 v;
 
-       if (!been_here) {
-               ao_lisp_root_add(&ao_lisp_cons_type, &read_cons);
-               ao_lisp_root_add(&ao_lisp_cons_type, &read_cons_tail);
-               ao_lisp_root_add(&ao_lisp_cons_type, &read_stack);
-       }
 
        cons = 0;
-       read_cons = read_cons_tail = read_stack = 0;
+       read_state = 0;
+       ao_lisp_read_cons = ao_lisp_read_cons_tail = ao_lisp_read_stack = 0;
        for (;;) {
+               parse_token = lex();
                while (parse_token == OPEN) {
-                       if (cons++)
-                               read_stack = ao_lisp_cons(ao_lisp_cons_poly(read_cons), read_stack);
-                       read_cons = NULL;
-                       read_cons_tail = NULL;
+                       if (!push_read_stack(cons, read_state))
+                               return AO_LISP_NIL;
+                       cons++;
+                       read_state = 0;
                        parse_token = lex();
                }
 
                switch (parse_token) {
-               case ENDOFFILE:
+               case END:
                default:
-                       v = AO_LISP_NIL;
+                       if (cons)
+                               ao_lisp_error(AO_LISP_EOF, "unexpected end of file");
+                       return _ao_lisp_atom_eof;
                        break;
                case NAME:
                        atom = ao_lisp_atom_intern(token_string);
@@ -402,6 +499,12 @@ read_item(void)
                case NUM:
                        v = ao_lisp_int_poly(token_int);
                        break;
+               case BOOL:
+                       if (token_string[0] == 't')
+                               v = _ao_lisp_bool_true;
+                       else
+                               v = _ao_lisp_bool_false;
+                       break;
                case STRING:
                        string = ao_lisp_string_copy(token_string);
                        if (string)
@@ -409,40 +512,67 @@ read_item(void)
                        else
                                v = AO_LISP_NIL;
                        break;
+               case QUOTE:
+                       if (!push_read_stack(cons, read_state))
+                               return AO_LISP_NIL;
+                       cons++;
+                       read_state = READ_IN_QUOTE;
+                       v = _ao_lisp_atom_quote;
+                       break;
                case CLOSE:
-                       if (cons)
-                               v = ao_lisp_cons_poly(read_cons);
-                       else
+                       if (!cons) {
                                v = AO_LISP_NIL;
-                       if (--cons) {
-                               read_cons = ao_lisp_poly_cons(read_stack->car);
-                               read_stack = read_stack->cdr;
-                               for (read_cons_tail = read_cons;
-                                    read_cons_tail && read_cons_tail->cdr;
-                                    read_cons_tail = read_cons_tail->cdr)
-                                       ;
+                               break;
                        }
+                       v = ao_lisp_cons_poly(ao_lisp_read_cons);
+                       --cons;
+                       read_state = pop_read_stack(cons);
                        break;
+               case DOT:
+                       if (!cons) {
+                               ao_lisp_error(AO_LISP_INVALID, ". outside of cons");
+                               return AO_LISP_NIL;
+                       }
+                       if (!ao_lisp_read_cons) {
+                               ao_lisp_error(AO_LISP_INVALID, ". first in cons");
+                               return AO_LISP_NIL;
+                       }
+                       read_state |= READ_SAW_DOT;
+                       continue;
                }
 
-               if (!cons)
-                       break;
+               /* loop over QUOTE ends */
+               for (;;) {
+                       if (!cons)
+                               return v;
 
-               struct ao_lisp_cons     *read = ao_lisp_cons(v, NULL);
-               if (read_cons_tail)
-                       read_cons_tail->cdr = read;
-               else
-                       read_cons = read;
-               read_cons_tail = read;
+                       if (read_state & READ_DONE_DOT) {
+                               ao_lisp_error(AO_LISP_INVALID, ". not last in cons");
+                               return AO_LISP_NIL;
+                       }
 
-               parse_token = lex();
+                       if (read_state & READ_SAW_DOT) {
+                               read_state |= READ_DONE_DOT;
+                               ao_lisp_read_cons_tail->cdr = v;
+                       } else {
+                               struct ao_lisp_cons     *read = ao_lisp_cons_cons(v, AO_LISP_NIL);
+                               if (!read)
+                                       return AO_LISP_NIL;
+
+                               if (ao_lisp_read_cons_tail)
+                                       ao_lisp_read_cons_tail->cdr = ao_lisp_cons_poly(read);
+                               else
+                                       ao_lisp_read_cons = read;
+                               ao_lisp_read_cons_tail = read;
+                       }
+
+                       if (!(read_state & READ_IN_QUOTE) || !ao_lisp_read_cons->cdr)
+                               break;
+
+                       v = ao_lisp_cons_poly(ao_lisp_read_cons);
+                       --cons;
+                       read_state = pop_read_stack(cons);
+               }
        }
        return v;
 }
-
-ao_lisp_poly
-ao_lisp_read(void)
-{
-       parse_token = lex();
-       return read_item();
-}