Resolving Expressions

Two structurally equivalent Expressions can be resolved against one another. This ranges from simple examples, such as

Expression A: ?a
Expression B: 5
Bindings:
 * ?a = 5

to more complex structures like this:

Expression A: ((?a ?b) ?c 5)
Expression B: ((1 2) (4 (test1 test2)) 5)
Bindings:
 * ?a = 1
 * ?b = 2
 * ?c = (4 (test1 test2))

You can put variables on both sides of the resolution:

Expression A: (?a 2)
Expression B: (1 ?b)
Bindings:
 * ?a = 1
 * ?b = 2

In C++, Expressions are resolved against each other like this:

Expression exA = Expression::parseSingle("(?a 2)");
Expression exB = Expression::parseSingle("(1 ?b)");

std::map<std::string, Expression> mapBindings;
if(exA.match(exB, mapBindings)) {
  // Structural match, no incompatible fields
  // Now do something with the bindings in mapBindings
} else {
  // No match
}