On 19 September 2014 06:05, Richard A. O'Keefe
drink (NewGlass i) j = (NewGlass i) -- Eq 1 drink (Fill m i) j | full (Fill m i) = Fill (NewGlass (size m)) ((size m) - j) -- Eq 2 | i >= j = Fill m (i-j) | otherwise = drink m (j-1)
First, (Fill m i) isn't *any* kind of constructor. Second, the first occurrence of (Fill m i) is a (data) pattern containing the (data) constructor Fill, and the second occurrence of (Fill m i) is an expression containing the (data) constructor Fill. We may not know what Glass, NewGlass, and Fill *mean*, but we know what they *are* (as Haskell thingies).
Your response has clarified most of my confusion. Please bear with my naivety as seek to ride my mind of confusion over these two point: 1) I do not know what the phrase "(Fill m i) isn't *any* kind of constructor." means. 2) Does "Fill (NewGlass (size m)) ((size m) - j) " create two Glass Haskell thingies? The context of this code is an attempt to formalize the drinking operation[1]. [1] www.ncgia.ucsb.edu/Publications/Tech_Reports/95/95-7.pdf -- This email originated from DIT. If you received this email in error, please delete it from your system. Please note that if you are not the named addressee, disclosing, copying, distributing or taking any action based on the contents of this email or attachments is prohibited. www.dit.ie Is ó ITBÁC a tháinig an ríomhphost seo. Má fuair tú an ríomhphost seo trí earráid, scrios de do chóras é le do thoil. Tabhair ar aird, mura tú an seolaí ainmnithe, go bhfuil dianchosc ar aon nochtadh, aon chóipeáil, aon dáileadh nó ar aon ghníomh a dhéanfar bunaithe ar an ábhar atá sa ríomhphost nó sna hiatáin seo. www.dit.ie Tá ITBÁC ag aistriú go Gráinseach Ghormáin – DIT is on the move to Grangegorman http://www.dit.ie/grangegorman