This may have been noted before, but it really confused me for a long time: Type checking ERROR "/usr/gem/hscr/bmark/RASeq/Connected.hs" (line 10): Type error in application *** expression : isEmpty g *** term : g *** type : Graph a b *** does not match : Graph c d I eventually found that the first "Graph" was different to the second "Graph" (they had been defined in different modules). For a trivial example that causes the same confusion, see the three appended files. Graeme. PS. Using Hugs1.4 June98. Uuencoded tar file follows. ------------------------------------------------------------------------------- import Hugs14Test7a (testA) import Hugs14Test7b (Test) test :: Test -> Bool test t = testA t ------------------------------------------------------------------------------- module Hugs14Test7a (testA) where data Test = Test testA :: Test -> Bool testA Test = True ------------------------------------------------------------------------------- module Hugs14Test7b (Test) where data Test = Test ------------------------------------------------------------------------------- begin 644 hugs14test7.tar.gz M'XL(`-X=W#8``^W536Z#,!0$8-8^Q2R312O;.(X4*97HJ@?(!8CBA$I!5 MZS<VRI]"FQ70Q7R;!^8)&>&QB_;0*.-=XY>O19,,0DEIC4$":*-TJ,"YQNO4 M`M;:I50V5>HTH*S4">0PT[G7-CZO@>3@RC_[3FW[_1@3&M=G^575'A]Q&6S" M,L@Q"\LAFXO'9UO,0IT+$5JP6B'<XN4-[U5U[`8]UH@O@!=3?QT]<_OCA]H` MGN=_<<F_-C;F?Z&8_S&4U:X]NM[\X[MPM1-BE_N\R_DZEB[\66_ZLTMCW3K& M__^[W=RGRC]L>CW_=9?_E/D?Q6/^SV?\K_&?>LI$1$1$1$1$1$1$1$1$1-3C )!WV8L#(`*``` ` end
