digitalmars.D.bugs - [Issue 9599] New: File.byLine doesn't function properly with take
- d-bugmail puremagic.com (42/42) Feb 26 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9599
- d-bugmail puremagic.com (38/39) Feb 27 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9599
- d-bugmail puremagic.com (9/13) Feb 27 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9599
- d-bugmail puremagic.com (11/15) Mar 13 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9599
- d-bugmail puremagic.com (13/27) Jul 22 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9599
- d-bugmail puremagic.com (19/19) Aug 19 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9599
- d-bugmail puremagic.com (9/9) Aug 19 2013 http://d.puremagic.com/issues/show_bug.cgi?id=9599
http://d.puremagic.com/issues/show_bug.cgi?id=9599 Summary: File.byLine doesn't function properly with take Product: D Version: D2 Platform: All OS/Version: All Status: NEW Severity: normal Priority: P2 Component: Phobos AssignedTo: nobody puremagic.com ReportedBy: zshazz gmail.com Using 2.062, Regarding the following code: --- import std.stdio, std.range; void main() { auto file = File.tmpfile(); file.write("1\n2\n3\n"); file.rewind(); auto fbl = file.byLine(); foreach(line; fbl.take(1)) writeln(line); foreach(line; fbl) writeln(line); } --- The expected output for this would be: --- 1 2 3 --- but actual output: --- 1 3 --- Generalized observation: When take is used on a ByLine range, it takes the appropriate number of elements and then consumes one additional element preventing anything else from using it. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Feb 26 2013
http://d.puremagic.com/issues/show_bug.cgi?id=9599 monarchdodra gmail.com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |monarchdodra gmail.comUsing 2.062, Regarding the following code:The bug is actually inside byLine itself, so we can remove take from the equation. The problem is that byLine is over-eager: 1) Creating a front element eagerly pops that element. 2) poping an element eagerlly parses the next, effectivelly popping it off too if it is never read: Reduced test showing this: //---- import std.stdio; void main() { auto file = File.tmpfile(); file.write("1\n2\n3\n4\n5"); file.rewind(); auto fbl1 = file.byLine(); writeln(fbl1.front); //prints 1. auto fbl2 = file.byLine(); writeln(fbl2.front); //prints 2... Wait. Who popped off 1? fbl2.popFront(); //pops off 2, and consumes 3. auto fbl3 = file.byLine(); writeln(fbl3.front); //prints 4. } //---- Ideally, byLine should be reworked to be a little more lazy, and better preserve the integrity of its underlying stream: - "front means do NOT modify the referenced container" - "pop means remove the CURRENT element, and stop there" byLine is obviously not doing that. The fact that it is *just* an input range does not mean it gets to bypass standard rules. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Feb 27 2013
http://d.puremagic.com/issues/show_bug.cgi?id=9599byChunk is subject to the exact same issue. The fact that they don't behave according to normal range semantics could be a potentially serious problems when not used linearly. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------Using 2.062, Regarding the following code:The bug is actually inside byLine itself
Feb 27 2013
http://d.puremagic.com/issues/show_bug.cgi?id=9599 monarchdodra gmail.com changed: What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|nobody puremagic.com |monarchdodra gmail.comIdeally, byLine should be reworked to be a little more lazy, and better preserve the integrity of its underlying stream: - "front means do NOT modify the referenced container" - "pop means remove the CURRENT element, and stop there"Either that, or take the -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Mar 13 2013
http://d.puremagic.com/issues/show_bug.cgi?id=9599 Nick Treleaven <ntrel-public yahoo.co.uk> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |pull CC| |ntrel-public yahoo.co.uk 08:32:06 PDT ---The bug is actually inside byLine itself, so we can remove take from the equation. The problem is that byLine is over-eager: 1) Creating a front element eagerly pops that element. 2) poping an element eagerlly parses the next, effectivelly popping it off too if it is never read:https://github.com/D-Programming-Language/phobos/pull/1433auto file = File.tmpfile(); file.write("1\n2\n3\n4\n5"); file.rewind(); auto fbl1 = file.byLine(); writeln(fbl1.front); //prints 1. auto fbl2 = file.byLine(); writeln(fbl2.front); //prints 2... Wait. Who popped off 1?I think the above behaviour is understandable for a range like ByLine. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Jul 22 2013
http://d.puremagic.com/issues/show_bug.cgi?id=9599 Commits pushed to master at https://github.com/D-Programming-Language/phobos https://github.com/D-Programming-Language/phobos/commit/4c2a8bea355e2a980b21d41c5454fe7a34de1777 Add unittest for issue 9599, plus some other byLine cases https://github.com/D-Programming-Language/phobos/commit/ec1f0fdb9d3f4b9ffd3acd444d27195ffc6a15fb Fix Issue 9599 - File.byLine doesn't function properly with take Calling take could wrongly pop an extra line from the range. Solved by making ByLine use reference-counting. Note: Just changing ByLine not to eagerly read the next line was not sufficient to handle all cases properly (plus that makes empty() less efficient). Note: ByLine was documented until recently. https://github.com/D-Programming-Language/phobos/commit/7bc6e8153921b10eb61179ec318e01b825ff94c5 Fix Issue 9599 - File.byLine doesn't function properly with take -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 19 2013
http://d.puremagic.com/issues/show_bug.cgi?id=9599 monarchdodra gmail.com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 19 2013