std::map<std::string,mstch::node> specs_lambdas {
    {"Interpolation", mstch::lambda{[](const std::string&) -> mstch::node {
      return std::string{"world"};
    }}},
    {"Interpolation - Expansion", mstch::lambda{[](const std::string&) -> mstch::node {
      return std::string{"{{planet}}"};
    }}},
    {"Interpolation - Multiple Calls", mstch::lambda{[](const std::string&) -> mstch::node {
      static int calls = 0; return ++calls;
    }}},
    {"Escaping", mstch::lambda{[](const std::string&) -> mstch::node {
      return std::string{">"};
    }}},
    {"Section", mstch::lambda{[](const std::string& txt) -> mstch::node {
      return std::string{(txt == "{{x}}") ? "yes" : "no"};
    }}},
    {"Section - Expansion", mstch::lambda{[](const std::string& txt) -> mstch::node {
      return txt + std::string{"{{planet}}"} + txt;
    }}},
    {"Section - Multiple Calls", mstch::lambda{[](const std::string& txt) -> mstch::node {
      return "__" + txt + "__";
    }}},
    {"Inverted Section", mstch::lambda{[](const std::string&) -> mstch::node {
      return false;
    }}}
};