J3/15-124 To: J3 From: John Reid & Bill Long Subject: Image-selector spec Date: 2015 February 09 Discussion ---------- In his recent ballot (see N2045) Malcolm Cohen wrote "I do not agree with the syntax for specifying a team variable in an image-selector, as we use double colons following type-specs and other related attributes, which this is certainly not. A single colon would be acceptable." We have considered both single and double colon notation. The problem with the single colon notation is that it visually looks like the notation for an array section. While we currently don't allow co-sections, it is a fairly obvious extension in the future. Earlier coarray extensions had already allowed it. In an email, Reinhold Bader wrote "Alternatively, one could consider making the notation analogous to the TEAM_ID one, say type(team_type) :: ancestor a[i, TEAM=ancestor] = ... Some characters more to type in, but also more consistent." We prefer this syntax and include edits here to implement it. As well as being "more consistent", the meaning is obvious to the reader of code - it does not rely on remembering the meaning of the double colon. Edits to N2040: --------------- [11:4-6] Replace R624 and C509 by "R624 <> <> <> [, ] R624a <> TEAM_ID = <> TEAM = " [11:7] Replace "" by "TEAM =" and "it" by "". [11:14+] In NOTE 5.2, line 2, replace "[ancestor::i]" by "[i,TEAM=ancestor]". [11:14+] In NOTE 5.3, lines -4 and -3, replace "[INITIAL::ME+1]" by "[ME+1,TEAM=INITIAL]" and "[INITIAL::ME-1]" by "[ME-1,TEAM=INITIAL]". [28:45] Replace "[PARENT_TEAM::1]" by "[1,TEAM=PARENT_TEAM]". [35:28-30] Replace R624 and C627A by "R624 <> <> <> [, ] R624a <> TEAM_ID = <> TEAM = " [35:33] Replace " or a TEAM_ID specifier if either" with "a if it".