Consider the following grammar with action routines:

Suppose we are parsing the input IN a, OUT b, and that our compiler uses an automatically maintained attribute stack to hold the active slice of the parse tree. Show the contents of this attribute stack immediately before the parser predicts the production par_tail → ∈. Be sure to indicate where L and R point in the attribute stack. Also show the stack of saved L and R values, showing where each points in the attribute stack. You may ignore the R pointer.

Transcribed Image Text:

mode ID par_tail { params.list := insert((mode.val, ID.name), par_tail.list) } , params { par_tail.list := params.list } { par_tail.list := null } + IN { mode.val := IN } params par_tail тode OUT { mode.val := OUT } IN OUT { mode.val := IN_OUT }