procedure Stmt( )

if ts.peek( ) = id

then

call match( ts, id )

call match( ts, assign )

call Val( ) call Expr( )

else if ts.peek( ) = print

then

call match( ts, print )

call match( ts, id )

else

call error( )

end

Figure 2.7: Recursive-descent parsing procedure for Stmt. The variable ts is an input stream of tokens.

Question

The recursive-descent code shown in Figure2.7 contains redundant tests for the presence of some terminal symbols. How would you decided which ones are redundant?