static Obj *read_expr(void *root) {
for (;;) {
int c = getchar();
if (c == ' ' || c == '\n' || c == '\r' || c == '\t')
continue;
if (c == EOF)
return NULL;
if (c == ';') {
skip_line();
continue;
}
if (c == '(')
return read_list(root);
if (c == ')')
return Cparen;
if (c == '.')
return Dot;
if (c == '\'')
return read_quote(root);
if (isdigit(c))
return make_int(root, read_number(c - '0'));
if (c == '-' && isdigit(peek()))
return make_int(root, -read_number(0));
if (isalpha(c) || strchr(symbol_chars, c))
return read_symbol(root, c);
error("Don't know how to handle %c", c);
}
}
alloc_t *read(FILE *f) {
alloc_t *x;
char c;
c = next_token_char(f);
if (c == '\'') {
x = read_quote(f);
} else if (c == '(') {
x = read_list(f);
} else if (c == ')') {
longjmp(fatal, ERROR_RIGHT_PAREN);
} else if (c != EOF) {
c = ungetc(c, f);
if (c == EOF) {
longjmp(fatal, ERROR_PUSHBACK);
}
x = read_symbol(f);
}
return x;
}
static Obj *read(Env *env, Obj *root, char **p) {
for (;;) {
char c = **p;
(*p)++;
if (c == '\0')
return NULL;
if (c == ' ' || c == '\n' || c == '\r' || c == '\t')
continue;
if (c == '(')
return read_sexp(env, root, p);
if (c == ')')
error("unclosed open parenthesis");
if (c == '\'')
return read_quote(env, root, p);
if (isdigit(c))
return read_number(env, root, p, c - '0');
if (isalpha(c) || strchr("+=!@#$%^&*", c))
return read_symbol(env, root, p, c);
error("don't know how to handle %c", c);
}
}
