| // a sketch of what the new API might look like |
| |
| #include "yaml-cpp/yaml.h" |
| #include <iostream> |
| |
| int main() { |
| { |
| // test.yaml |
| // - foo |
| // - primes: [2, 3, 5, 7, 11] |
| // odds: [1, 3, 5, 7, 9, 11] |
| // - [x, y] |
| |
| // move-like semantics |
| YAML::Value root = YAML::Parse("test.yaml"); |
| |
| std::cout << root[0].as<std::string>(); // "foo" |
| std::cout << str(root[0]); // "foo", shorthand? |
| std::cout << root[1]["primes"][3].as<int>(); // "7" |
| std::cout << root[1]["odds"][6].as<int>(); // throws? |
| |
| root[2].push_back(5); |
| root[3] = "Hello, World"; |
| root[0].reset(); |
| root[0]["key"] = "value"; |
| |
| std::cout << root; |
| // # not sure about formatting |
| // - {key: value} |
| // - primes: [2, 3, 5, 7, 11] |
| // odds: [1, 3, 5, 7, 9, 11] |
| // - [x, y, 5] |
| // - Hello, World |
| } |
| |
| { |
| // for all copy-like commands, think of python's "name/value" semantics |
| YAML::Value root = "Hello"; // Hello |
| root = YAML::Sequence(); // [] |
| root[0] = 0; // [0] |
| root[2] = "two"; // [0, ~, two] # forces root[1] to be initialized to null |
| |
| YAML::Value other = root; // both point to the same thing |
| other[0] = 5; // now root[0] is 0 also |
| other.push_back(root); // &1 [5, ~, two, *1] |
| other[3][0] = 0; // &1 [0, ~, two, *1] # since it's a true alias |
| other.push_back(Copy(root)); // &1 [0, ~, two, *1, &2 [0, ~, two, *2]] |
| other[4][0] = 5; // &1 [0, ~, two, *1, &2 [5, ~, two, *2]] # they're |
| // really different |
| } |
| |
| { |
| YAML::Value node; // ~ |
| node[0] = 1; // [1] # auto-construct a sequence |
| node["key"] = 5; // {0: 1, key: 5} # auto-turn it into a map |
| node.push_back(10); // error, can't turn a map into a sequence |
| node.erase("key"); // {0: 1} # still a map, even if we remove the key that |
| // caused the problem |
| node = "Hello"; // Hello # assignment overwrites everything, so it's now |
| // just a plain scalar |
| } |
| |
| { |
| YAML::Value map; // ~ |
| map[3] = 1; // {3: 1} # auto-constructs a map, *not* a sequence |
| |
| YAML::Value seq; // ~ |
| seq = YAML::Sequence(); // [] |
| seq[3] = 1; // [~, ~, ~, 1] |
| } |
| |
| { |
| YAML::Value node; // ~ |
| node[0] = node; // &1 [*1] # fun stuff |
| } |
| |
| { |
| YAML::Value node; |
| YAML::Value subnode = |
| node["key"]; // 'subnode' is not instantiated ('node' is still null) |
| subnode = "value"; // {key: value} # now it is |
| YAML::Value subnode2 = node["key2"]; |
| node["key3"] = subnode2; // subnode2 is still not instantiated, but |
| // node["key3"] is "pseudo" aliased to it |
| subnode2 = "monkey"; // {key: value, key2: &1 monkey, key3: *1} # bam! it |
| // instantiates both |
| } |
| |
| { |
| YAML::Value seq = YAML::Sequence(); |
| seq[0] = "zero"; // [zero] |
| seq[1] = seq[0]; // [&1 zero, *1] |
| seq[0] = seq[1]; // [&1 zero, *1] # no-op (they both alias the same thing, |
| // so setting them equal is nothing) |
| Is(seq[0], seq[1]); // true |
| seq[1] = "one"; // [&1 one, *1] |
| UnAlias(seq[1]); // [one, one] |
| Is(seq[0], seq[1]); // false |
| } |
| |
| { |
| YAML::Value root; |
| root.push_back("zero"); |
| root.push_back("one"); |
| root.push_back("two"); |
| YAML::Value two = root[2]; |
| root = "scalar"; // 'two' is still "two", even though 'root' is "scalar" |
| // (the sequence effectively no longer exists) |
| |
| // Note: in all likelihood, the memory for nodes "zero" and "one" is still |
| // allocated. How can it go away? Weak pointers? |
| } |
| |
| { |
| YAML::Value root; // ~ |
| root[0] = root; // &1 [*1] |
| root[0] = 5; // [5] |
| } |
| |
| { |
| YAML::Value root; |
| YAML::Value key; |
| key["key"] = "value"; |
| root[key] = key; // &1 {key: value}: *1 |
| } |
| |
| { |
| YAML::Value root; |
| root[0] = "hi"; |
| root[1][0] = "bye"; |
| root[1][1] = root; // &1 [hi, [bye, *1]] # root |
| YAML::Value sub = root[1]; // &1 [bye, [hi, *1]] # sub |
| root = "gone"; // [bye, gone] # sub |
| } |
| |
| return 0; |
| } |