Challenges of a type error slicer for the SML language
Vincent Rahli, J. B. Wells, Fairouz Kamareddine · 2009
SML (a higher-order function-oriented imperative programming language) depends on automated inference of sophisticated type information. Existing implementations have confusing type error messages. Type error slicing gives the programmer more helpful type error information: (1) It identifies all program points that contribute to a type error rather than blaming just one point. (2) It exhibits a slice of the original program’s syntax instead of showing an internal representation of some program subtree which may have been substantially transformed. (3) It avoids showing internal details of inferred types which were not written by the programmer. A type error slice contains all information needed to understand the error, and avoids irrelevant information. Similar to other previous work for better handling of type errors, type error slicing was initially developed for a very tiny toy