RuleDSLActions

Pushes the input text matched by its inner rule onto the value stack after its inner rule has been run successfully (and only then).

Drops one or more values from the top of the value stack. E.g. drop[Int] will drop the top Int value and drop[Int :: String :: HNil] will drop the top two values, which must be an Int underneath a String (the string being the top stack element).

Pushes the given value onto the value stack.

• if T is Unit nothing is pushed (i.e. push with a block/expression evaluating to Unit is identical to run)
• if T <: HList all values of the HList is pushed as individual elements
• otherwise a single value of type T is pushed.

Runs the given block / expression / action function. A run rule can have several shapes, depending on its argument type. If the arg evaluates to

• a rule (i.e. has type R <: Rule[_, _]) the result type of run is this rule's type (i.e. R) and the produced rule is immediately executed.

• a function with 1 to 5 parameters these parameters are mapped against the top of the value stack, popped and the function executed. Thereby the function behaves just like an action function for the ~> operator, i.e. if it produces a Unit value this result is simply dropped. HList results are pushed onto the value stack (all their elements individually), rule results are immediately executed and other result values are pushed onto the value stack as a single element.

• a function with one HList parameter the behavior is similar to the previous case with the difference that the elements of this parameter HList are mapped against the value stack top. This allows for consumption of an arbitrary number of value stack elements. (Note: This feature of run is not yet currently implemented.)

• any other value the result type of run is an always succeeding Rule0.

NOTE: Even though the block is not a call-by-name parameter it will be executed for every rule application anew! (Since the expression is directly transplanted into the rule method by the rule macro.

Implements a semantic predicate. If the argument expression evaluates to true the created rule matches otherwise it doesn't.