F# 4.0 Design Patterns

Arranging matching rules

Wildcard pattern demonstrates the importance of arranging the match cases from more specific to less specific. For example, if I put the match all third rule with the wildcard pattern before the first two rules in the preceding script, then the F# compiler will put the blue squiggle line under explicit Multiples values, indicating that these rules will never be matched (check out transformB'' definition in Ch4_1.fsx).