DrScheme's constructor-style output treats cons, vector, and similar primitives as value constructors, rather than functions. It also treats list as shorthand for multiple cons's ending with the empty list. Constructor-style printing is valuable for beginning computer science students, because output values look the same as input values.
Results printed in DrScheme's interactions window using
constructor-style printing look different than results printed in
traditional Scheme implementations, which use write to print
results. The table in Figure shows the
differences between values printed in constructor style and values
printed with write.
Figure: Comparison of constructor-style output to write