To: J3 J3/13-317r1 From: Dan Nagle & Malcolm Cohen Subject: delete obsolete DO forms UK-10.1b Date: 2013 October 14 Obsolete forms of the DO loop are hard to understand, especially for modern programmers, and are error prone. They are redundant with block loops. UK Item 10 subitem 1b, accepted at Delft, advocates deleting these forms. Specification: The non block forms of the do loop are deleted. The shared termination forms of the do loop are deleted. Syntax: The non block forms are no longer valid syntax. Shared termination of do loops is no longer valid syntax. Edits: [intro] Add new feature "The nonblock forms of the DO construct have been deleted." {remove obsolete terms from branch target statement definition} [4:38] delete ", ," {remove alternative definitions} [174:12] Delete paragraph 5 (no info). [174:13-14] Delete rule R813 entirely. [174:15: 8.1.6.2 heading, delete "block". [174:16] R814, delete "block-". {the main event} [175:6-32] delete subclause 8.1.6.3 {NOTE: This deletes text that would otherwise be changed by 13-316.} {remove non-block do from range discussion} [175:37-42] delete the paragraph {remove non-block discuss from the execution cycle discussion} [176:28-31] delete the small-font sentences, that is, delete "If, as a result, ... was most recently executed." {repair cycle discussion} [177:12-13] delete the final sentence of the paragraph: "If this ... is not executed." [177:17-19] delete the final two sentences of the paragraph: "In a non block ... is then executed." {repair discussion of branching} [187:6] delete "a , a ," {add to deleted list} {note interaction with edits proposed in 13-316} [463++] add "(8) Nonblock DO loops The non block forms of the do loop were confusing and hard to maintain. The use of labeled action statements as branch targets was especially difficult for modern programmers to fathom. {repair the obsolescent list} [464:7-8] delete bullet (2) {clean the examples} [484:32-485:37] delete the lot