1 // So far instructions can only contain linear lists of properties. Now we add
  2 // support for more complex trees of properties in dilated reagents. This will
  3 // come in handy later for expressing complex types, like "a dictionary from
  4 // (address to array of charaters) to (list of numbers)".
  5 //
  6 // Type trees aren't as general as s-expressions even if they look like them:
  7 // the first element of a type tree is always an atom, and it can never be
  8 // dotted (right->right->right->...->right is always NULL).
  9 //
 10 // For now you can't use the simpler 'colon-based' representation inside type
 11 // trees. Once you start typing parens, keep on typing parens.
 12 
 13 :(scenarios load)
 14 :(scenario dilated_reagent_with_nested_brackets)
 15 def main [
 16   {1: number, foo: (bar (baz quux))} <- copy 34
 17 ]
 18 +parse:   product: {1: "number", "foo": ("bar" ("baz" "quux"))}
 19 
 20 :(before "End Parsing Dilated Reagent Property(value)")
 21 value = parse_string_tree(value);
 22 :(before "End Parsing Dilated Reagent Type Property(type_names)")
 23 type_names = parse_string_tree(type_names);
 24 
 25 :(code)
 26 string_tree* parse_string_tree(string_tree* s) {
 27   assert(s->atom);
 28   if (!starts_with(s->value, "(")) return s;
 29   string_tree* result = parse_string_tree(s->value);
 30   delete s;
 31   return result;
 32 }
 33 
 34 string_tree* parse_string_tree(const string& s) {
 35   istringstream in(s);
 36   in >> std::noskipws;
 37   return parse_string_tree(in);
 38 }
 39 
 40 string_tree* parse_string_tree(istream& in) {
 41   skip_whitespace_but_not_newline(in);
 42   if (!has_data(in)) return NULL;
 43   if (in.peek() == ')') {
 44   ¦ in.get();
 45   ¦ return NULL;
 46   }
 47   if (in.peek() != '(') {
 48   ¦ string s = next_word(in);
 49   ¦ if (s.empty()) {
 50   ¦ ¦ assert(!has_data(in));
 51   ¦ ¦ raise << "incomplete string tree at end of file (0)\n" << end();
 52   ¦ ¦ return NULL;
 53   ¦ }
 54   ¦ string_tree* result = new string_tree(s);
 55   ¦ return result;
 56   }
 57   in.get();  // skip '('
 58   string_tree* result = NULL;
 59   string_tree** curr = &result;
 60   while (true) {
 61   ¦ skip_whitespace_but_not_newline(in);
 62   ¦ assert(has_data(in));
 63   ¦ if (in.peek() == ')') break;
 64   ¦ *curr = new string_tree(NULL, NULL);
 65   ¦ if (in.peek() == '(') {
 66   ¦ ¦ (*curr)->left = parse_string_tree(in);
 67   ¦ }
 68   ¦ else {
 69   ¦ ¦ string s = next_word(in);
 70   ¦ ¦ if (s.empty()) {
 71   ¦ ¦ ¦ assert(!has_data(in));
 72   ¦ ¦ ¦ raise << "incomplete string tree at end of file (1)\n" << end();
 73   ¦ ¦ ¦ return NULL;
 74   ¦ ¦ }
 75   ¦ ¦ (*curr)->left = new string_tree(s);
 76   ¦ }
 77   ¦ curr = &(*curr)->right;
 78   }
 79   in.get();  // skip ')'
 80   assert(*curr == NULL);
 81   return result;
 82 }
 83 
 84 :(scenario dilated_reagent_with_type_tree)
 85 % Hide_errors = true;  // 'map' isn't defined yet
 86 def main [
 87   {1: (foo (address array character) (bar number))} <- copy 34
 88 ]
 89 # just to avoid errors
 90 container foo [
 91 ]
 92 container bar [
 93 ]
 94 +parse:   product: {1: ("foo" ("address" "array" "character") ("bar" "number"))}
 95 
 96 :(scenario dilated_empty_tree)
 97 def main [
 98   {1: number, foo: ()} <- copy 34
 99 ]
100 +parse:   product: {1: "number", "foo": ()}
101 
102 :(scenario dilated_singleton_tree)
103 def main [
104   {1: number, foo: (bar)} <- copy 34
105 ]
106 +parse:   product: {1: "number", "foo": ("bar")}