From e7863e8964becbbcf8ada621163156cbb37e8d36 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Del=20Pino?= <stephane.delpino44@gmail.com>
Date: Mon, 30 May 2022 16:57:07 +0200
Subject: [PATCH] Add do...while documentation
---
doc/userdoc.org | 39 +++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)
diff --git a/doc/userdoc.org b/doc/userdoc.org
index 092dcc3d6..fd14d7803 100644
--- a/doc/userdoc.org
+++ b/doc/userdoc.org
@@ -1880,7 +1880,7 @@ We give a final illustration
*** ~for~ loops
-~pugs~ allow to write ~for~ loops. It follows the ~C++~ syntax
+~pugs~ allows to write ~for~ loops. It follows the ~C++~ syntax
#+BEGIN_SRC pugs :exports code
for (declarationinstruction ; condition ; postinstruction) statement
#+END_SRC
@@ -1937,8 +1937,43 @@ To fix the previous code, one can write
One gets
#+results: for-no-decl
+*** ~do...while~ loops
-*** TODO do while loops
+The second kind of loops that can be written is the ~do...while~
+construction which executes /at least/ one time the enclosed ~statement~.
+#+BEGIN_SRC pugs :exports code
+ do statement while (condition);
+#+END_SRC
+
+The ~statement~ is either a single instruction or a block of
+instructions. The ~condition~ is an expression of boolean value (type
+~B~).
+
+#+NAME: do-while-instr
+#+BEGIN_SRC pugs :exports both :results output
+ let sum:N, sum = 0;
+ let i:N, i = 0;
+ do
+ sum += i++;
+ while (i<=10);
+ cout << "sum = " << sum << "\n";
+#+END_SRC
+This code produces
+#+results: do-while-instr
+
+However, to ease the reading, it is probably better to write
+#+NAME: do-while-block
+#+BEGIN_SRC pugs :exports both :results output
+ let sum:N, sum = 0;
+ let i:N, i = 0;
+ do {
+ sum += i;
+ ++i;
+ } while (i<=10);
+ cout << "sum = " << sum << "\n";
+#+END_SRC
+It gives also
+#+results: do-while-block
*** TODO while loops
--
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