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  • Reusable VS clean code - where's the balance?

    - by Radek Šimko
    Let's say I have a data model for a blog posts and have two use-cases of that model - getting all blogposts and getting only blogposts which were written by specific author. There are basically two ways how I can realize that. 1st model class Articles { public function getPosts() { return $this->connection->find() ->sort(array('creation_time' => -1)); } public function getPostsByAuthor( $authorUid ) { return $this->connection->find(array('author_uid' => $authorUid)) ->sort(array('creation_time' => -1)); } } 1st usage (presenter/controller) if ( $GET['author_uid'] ) { $posts = $articles->getPostsByAuthor($GET['author_uid']); } else { $posts = $articles->getPosts(); } 2nd one class Articles { public function getPosts( $authorUid = NULL ) { $query = array(); if( $authorUid !== NULL ) { $query = array('author_uid' => $authorUid); } return $this->connection->find($query) ->sort(array('creation_time' => -1)); } } 2nd usage (presenter/controller) $posts = $articles->getPosts( $_GET['author_uid'] ); To sum up (dis)advantages: 1) cleaner code 2) more reusable code Which one do you think is better and why? Is there any kind of compromise between those two?

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  • Where should I start reading AngularJS's source code?

    - by Abaco
    After reading this article I realized that I really didn't read any "serious" source code during my 3-years as a professional developer. Recently I started a new web-project which makes heavy use of AngularJS, so I decided to start my reading - or, better, decoding [as the blogger wrote] - activity from something that is both challenging and professionally useful. Now I just need to be pointed in the right direction. Should I just start from the start of the source code or is there a better starting point?

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  • code metrics for .net code

    - by user20358
    While the code metrics tool gives a pretty good analysis of the code being analyzed, I was wondering if there was any such benchmark on acceptable standards for the following as well: Maximum number of types per assembly Maximum number of such types that can be accessible Maximum number of parameters per method Acceptable RFC count Acceptable Afferent coupling count Acceptable Efferent coupling count Any other metrics to judge the quality of .Net code by? Thanks for your time.

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  • What code smell best describes this code?

    - by Paul Stovell
    Suppose you have this code in a class: private DataContext _context; public Customer[] GetCustomers() { GetContext(); return _context.Customers.ToArray(); } public Order[] GetOrders() { GetContext(); return _context.Customers.ToArray(); } // For the sake of this example, a new DataContext is *required* // for every public method call private void GetContext() { if (_context != null) { _context.Dispose(); } _context = new DataContext(); } This code isn't thread-safe - if two calls to GetOrders/GetCustomers are made at the same time from different threads, they may end up using the same context, or the context could be disposed while being used. Even if this bug didn't exist, however, it still "smells" like bad code. A much better design would be for GetContext to always return a new instance of DataContext and to get rid of the private field, and to dispose of the instance when done. Changing from an inappropriate private field to a local variable feels like a better solution. I've looked over the code smell lists and can't find one that describes this. In the past I've thought of it as temporal coupling, but the Wikipedia description suggests that's not the term: Temporal coupling When two actions are bundled together into one module just because they happen to occur at the same time. This page discusses temporal coupling, but the example is the public API of a class, while my question is about the internal design. Does this smell have a name? Or is it simply "buggy code"?

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  • Java code critique request [closed]

    - by davidk01
    Can you make sense of the following bit of java code and do you have any suggestions for improving it? Instead of writing four almost identical setOnClickListener method calls I opted to iterate over an array but I'm wondering if this was the best way to do it. Here's the code: /* Set up the radio button click listeners so two categories are not selected at the same time. When one of them is clicked it clears the others. */ final RadioButton[] buttons = {radio_books,radio_games,radio_dvds,radio_electronics}; for (int i = 0; i < 4; i++) { final int k = i; buttons[i].setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { for (int j = 0; j < 4; j++) { if (buttons[j] != buttons[k]) { buttons[j].setChecked(false); } } } }); }

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  • Udev webcam rule read, but not respected?

    - by user89305
    I have two usb-webcams on them machine, but at bot they some switch /dev/video number. The solution to this problem seems to be new udev rule. I have added this rule in/etc/udev/rules.d/jj-video.rules: Fix webcam 1 KERNEL=="video1", SUBSYSTEM=="video4linux", SUBSYSTEMS=="usb", ATTRS{idVendor}=="1d6b", ATTRS{idProduct}=="0001", SYMLINK+="webcam1" Fix webcam 2 KERNEL=="video2", SUBSYSTEM=="video4linux", ATTR{name}=="Logitech QuickCam Pro 3000", KERNELS=="0000:00:1d.0", SUBSYSTEMS=="pci", DRIVERS=="uhci_hcd", ATTRS{vendor}=="0x8086", ATTRS##{device}=="0x2658", SYMLINK+="webcam2" but the symlinks are not created. I have tried many different combinations in this file. The present ones are just my lates attempts. I found the parameters in: jjk@eee-old:~$ udevadm info -a -p $(udevadm info -q path -p /class/video4linux/video1) Udevadm info starts with the device specified by the devpath and then walks up the chain of parent devices. It prints for every device found, all possible attributes in the udev rules key format. A rule to match, can be composed by the attributes of the device and the attributes from one single parent device. looking at device '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1': KERNEL=="video1" SUBSYSTEM=="video4linux" DRIVER=="" ATTR{name}=="Logitech QuickCam Pro 3000" ATTR{index}=="0" ATTR{button}=="0" looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0': KERNELS=="2-2:1.0" SUBSYSTEMS=="usb" DRIVERS=="Philips webcam" ATTRS{bInterfaceNumber}=="00" ATTRS{bAlternateSetting}==" 9" ATTRS{bNumEndpoints}=="02" ATTRS{bInterfaceClass}=="0a" ATTRS{bInterfaceSubClass}=="ff" ATTRS{bInterfaceProtocol}=="00" ATTRS{supports_autosuspend}=="0" looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-2': KERNELS=="2-2" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{configuration}=="" ATTRS{bNumInterfaces}==" 3" ATTRS{bConfigurationValue}=="1" ATTRS{bmAttributes}=="a0" ATTRS{bMaxPower}=="500mA" ATTRS{urbnum}=="371076" ATTRS{idVendor}=="046d" ATTRS{idProduct}=="08b0" ATTRS{bcdDevice}=="0002" ATTRS{bDeviceClass}=="00" ATTRS{bDeviceSubClass}=="00" ATTRS{bDeviceProtocol}=="00" ATTRS{bNumConfigurations}=="1" ATTRS{bMaxPacketSize0}=="8" ATTRS{speed}=="12" ATTRS{busnum}=="2" ATTRS{devnum}=="2" ATTRS{devpath}=="2" ATTRS{version}==" 1.10" ATTRS{maxchild}=="0" ATTRS{quirks}=="0x0" ATTRS{avoid_reset_quirk}=="0" ATTRS{authorized}=="1" ATTRS{serial}=="01402100A5000000" looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2': KERNELS=="usb2" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{configuration}=="" ATTRS{bNumInterfaces}==" 1" ATTRS{bConfigurationValue}=="1" ATTRS{bmAttributes}=="e0" ATTRS{bMaxPower}==" 0mA" ATTRS{urbnum}=="34" ATTRS{idVendor}=="1d6b" ATTRS{idProduct}=="0001" ATTRS{bcdDevice}=="0302" ATTRS{bDeviceClass}=="09" ATTRS{bDeviceSubClass}=="00" ATTRS{bDeviceProtocol}=="00" ATTRS{bNumConfigurations}=="1" ATTRS{bMaxPacketSize0}=="64" ATTRS{speed}=="12" ATTRS{busnum}=="2" ATTRS{devnum}=="1" ATTRS{devpath}=="0" ATTRS{version}==" 1.10" ATTRS{maxchild}=="2" ATTRS{quirks}=="0x0" ATTRS{avoid_reset_quirk}=="0" ATTRS{authorized}=="1" ATTRS{manufacturer}=="Linux 3.2.0-29-generic uhci_hcd" ATTRS{product}=="UHCI Host Controller" ATTRS{serial}=="0000:00:1d.0" ATTRS{authorized_default}=="1" looking at parent device '/devices/pci0000:00/0000:00:1d.0': KERNELS=="0000:00:1d.0" SUBSYSTEMS=="pci" DRIVERS=="uhci_hcd" ATTRS{vendor}=="0x8086" ATTRS{device}=="0x2658" ATTRS{subsystem_vendor}=="0x1043" ATTRS{subsystem_device}=="0x82d8" ATTRS{class}=="0x0c0300" ATTRS{irq}=="23" ATTRS{local_cpus}=="ff" ATTRS{local_cpulist}=="0-7" ATTRS{dma_mask_bits}=="32" ATTRS{consistent_dma_mask_bits}=="32" ATTRS{broken_parity_status}=="0" ATTRS{msi_bus}=="" looking at parent device '/devices/pci0000:00': KERNELS=="pci0000:00" SUBSYSTEMS=="" DRIVERS=="" jjk@eee-old:~$ And tested the setup: sudo udevadm --debug test /sys/class/video4linux/video1 main: runtime dir '/run/udev' run_command: calling: test adm_test: version 175 This program is for debugging only, it does not run any program, specified by a RUN key. It may show incorrect results, because some values may be different, or not available at a simulation run. parse_file: reading '/lib/udev/rules.d/40-crda.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-fuse.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-gnupg.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-hplip.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-ia64.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-inputattach.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-libgphoto2-2.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-libsane.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-ppc.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-usb_modeswitch.rules' as rules file parse_file: reading '/lib/udev/rules.d/40-xserver-xorg-video-intel.rules' as rules file parse_file: reading '/lib/udev/rules.d/42-qemu-usb.rules' as rules file parse_file: reading '/lib/udev/rules.d/50-firmware.rules' as rules file parse_file: reading '/lib/udev/rules.d/50-udev-default.rules' as rules file parse_file: reading '/lib/udev/rules.d/55-dm.rules' as rules file parse_file: reading '/lib/udev/rules.d/56-hpmud_support.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-cdrom_id.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-pcmcia.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-persistent-alsa.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-persistent-input.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-persistent-serial.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-persistent-storage-dm.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-persistent-storage-tape.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-persistent-storage.rules' as rules file parse_file: reading '/lib/udev/rules.d/60-persistent-v4l.rules' as rules file parse_file: reading '/lib/udev/rules.d/61-accelerometer.rules' as rules file parse_file: reading '/lib/udev/rules.d/64-xorg-xkb.rules' as rules file parse_file: reading '/lib/udev/rules.d/66-xorg-synaptics-quirks.rules' as rules file parse_file: reading '/lib/udev/rules.d/69-cd-sensors.rules' as rules file add_rule: IMPORT found builtin 'usb_id', replacing /lib/udev/rules.d/69-cd-sensors.rules:76 parse_file: reading '/lib/udev/rules.d/69-libmtp.rules' as rules file parse_file: reading '/lib/udev/rules.d/69-xorg-vmmouse.rules' as rules file parse_file: reading '/lib/udev/rules.d/69-xserver-xorg-input-wacom.rules' as rules file parse_file: reading '/etc/udev/rules.d/70-persistent-cd.rules' as rules file parse_file: reading '/etc/udev/rules.d/70-persistent-net.rules' as rules file parse_file: reading '/lib/udev/rules.d/70-printers.rules' as rules file parse_file: reading '/lib/udev/rules.d/70-udev-acl.rules' as rules file parse_file: reading '/lib/udev/rules.d/75-cd-aliases-generator.rules' as rules file parse_file: reading '/lib/udev/rules.d/75-net-description.rules' as rules file parse_file: reading '/lib/udev/rules.d/75-persistent-net-generator.rules' as rules file parse_file: reading '/lib/udev/rules.d/75-probe_mtd.rules' as rules file parse_file: reading '/lib/udev/rules.d/75-tty-description.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-ericsson-mbm.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-longcheer-port-types.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-nokia-port-types.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-pcmcia-device-blacklist.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-platform-serial-whitelist.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-qdl-device-blacklist.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-simtech-port-types.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-usb-device-blacklist.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-x22x-port-types.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-mm-zte-port-types.rules' as rules file parse_file: reading '/lib/udev/rules.d/77-nm-olpc-mesh.rules' as rules file parse_file: reading '/lib/udev/rules.d/78-graphics-card.rules' as rules file parse_file: reading '/lib/udev/rules.d/78-sound-card.rules' as rules file parse_file: reading '/lib/udev/rules.d/80-drivers.rules' as rules file parse_file: reading '/lib/udev/rules.d/80-mm-candidate.rules' as rules file parse_file: reading '/lib/udev/rules.d/80-udisks.rules' as rules file parse_file: reading '/lib/udev/rules.d/85-brltty.rules' as rules file parse_file: reading '/lib/udev/rules.d/85-hdparm.rules' as rules file parse_file: reading '/lib/udev/rules.d/85-hplj10xx.rules' as rules file parse_file: reading '/lib/udev/rules.d/85-keyboard-configuration.rules' as rules file parse_file: reading '/lib/udev/rules.d/85-regulatory.rules' as rules file parse_file: reading '/lib/udev/rules.d/85-usbmuxd.rules' as rules file parse_file: reading '/lib/udev/rules.d/90-alsa-restore.rules' as rules file parse_file: reading '/lib/udev/rules.d/90-alsa-ucm.rules' as rules file parse_file: reading '/lib/udev/rules.d/90-libgpod.rules' as rules file parse_file: reading '/lib/udev/rules.d/90-pulseaudio.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-cd-devices.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-keyboard-force-release.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-keymap.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-udev-late.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-dell.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-fujitsu.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-gateway.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-ibm.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-lenovo.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-toshiba.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-csr.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-hid.rules' as rules file parse_file: reading '/lib/udev/rules.d/95-upower-wup.rules' as rules file parse_file: reading '/lib/udev/rules.d/97-bluetooth-hid2hci.rules' as rules file parse_file: reading '/etc/udev/rules.d/jj-video.rules' as rules file udev_rules_new: rules use 259284 bytes tokens (21607 * 12 bytes), 37913 bytes buffer udev_rules_new: temporary index used 67520 bytes (3376 * 20 bytes) udev_device_new_from_syspath: device 0x215103e0 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1' udev_device_new_from_syspath: device 0x21510758 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1' udev_device_read_db: device 0x21510758 filled with db file data udev_device_new_from_syspath: device 0x21510e10 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0' udev_device_new_from_syspath: device 0x21511b10 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2' udev_device_new_from_syspath: device 0x215132f8 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2' udev_device_new_from_syspath: device 0x21513650 has devpath '/devices/pci0000:00/0000:00:1d.0' udev_device_new_from_syspath: device 0x21513980 has devpath '/devices/pci0000:00' udev_rules_apply_to_event: GROUP 44 /lib/udev/rules.d/50-udev-default.rules:29 udev_rules_apply_to_event: IMPORT 'v4l_id /dev/video1' /lib/udev/rules.d/60-persistent-v4l.rules:7 udev_event_spawn: starting 'v4l_id /dev/video1' spawn_read: 'v4l_id /dev/video1'(out) 'ID_V4L_VERSION=2' spawn_read: 'v4l_id /dev/video1'(out) 'ID_V4L_PRODUCT=Logitech QuickCam Pro 3000' spawn_read: 'v4l_id /dev/video1'(out) 'ID_V4L_CAPABILITIES=:capture:' spawn_wait: 'v4l_id /dev/video1' [2609] exit with return code 0 udev_rules_apply_to_event: IMPORT builtin 'usb_id' /lib/udev/rules.d/60-persistent-v4l.rules:9 builtin_usb_id: /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0: if_class 10 protocol 0 udev_builtin_add_property: ID_VENDOR=046d udev_builtin_add_property: ID_VENDOR_ENC=046d udev_builtin_add_property: ID_VENDOR_ID=046d udev_builtin_add_property: ID_MODEL=08b0 udev_builtin_add_property: ID_MODEL_ENC=08b0 udev_builtin_add_property: ID_MODEL_ID=08b0 udev_builtin_add_property: ID_REVISION=0002 udev_builtin_add_property: ID_SERIAL=046d_08b0_01402100A5000000 udev_builtin_add_property: ID_SERIAL_SHORT=01402100A5000000 udev_builtin_add_property: ID_TYPE=generic udev_builtin_add_property: ID_BUS=usb udev_builtin_add_property: ID_USB_INTERFACES=:0aff00:010100:010200: udev_builtin_add_property: ID_USB_INTERFACE_NUM=00 udev_builtin_add_property: ID_USB_DRIVER=Philips webcam udev_rules_apply_to_event: LINK 'v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0' /lib/udev/rules.d/60-persistent-v4l.rules:10 udev_rules_apply_to_event: IMPORT builtin 'path_id' /lib/udev/rules.d/60-persistent-v4l.rules:16 udev_builtin_add_property: ID_PATH=pci-0000:00:1d.0-usb-0:2:1.0 udev_builtin_add_property: ID_PATH_TAG=pci-0000_00_1d_0-usb-0_2_1_0 udev_rules_apply_to_event: LINK 'v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0' /lib/udev/rules.d/60-persistent-v4l.rules:17 udev_rules_apply_to_event: RUN 'udev-acl --action=$env{ACTION} --device=$env{DEVNAME}' /lib/udev/rules.d/70-udev-acl.rules:74 udev_rules_apply_to_event: LINK 'webcam1' /etc/udev/rules.d/jj-video.rules:2 udev_event_execute_rules: no node name set, will use kernel supplied name 'video1' udev_node_add: creating device node '/dev/video1', devnum=81:1, mode=0660, uid=0, gid=44 udev_node_mknod: preserve file '/dev/video1', because it has correct dev_t udev_node_mknod: preserve permissions /dev/video1, 020660, uid=0, gid=44 node_symlink: preserve already existing symlink '/dev/char/81:1' to '../video1' link_find_prioritized: found 'c81:2' claiming '/run/udev/links/v4l\x2fby-id\x2fusb-046d_08b0_01402100A5000000-video-index0' udev_device_new_from_syspath: device 0x21516748 has devpath '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/video4linux/video2' udev_device_read_db: device 0x21516748 filled with db file data link_find_prioritized: found 'c81:1' claiming '/run/udev/links/v4l\x2fby-id\x2fusb-046d_08b0_01402100A5000000-video-index0' link_update: creating link '/dev/v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0' to '/dev/video1' node_symlink: atomically replace '/dev/v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0' link_find_prioritized: found 'c81:1' claiming '/run/udev/links/v4l\x2fby-path\x2fpci-0000:00:1d.0-usb-0:2:1.0-video-index0' link_update: creating link '/dev/v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0' to '/dev/video1' node_symlink: preserve already existing symlink '/dev/v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0' to '../../video1' link_find_prioritized: found 'c81:1' claiming '/run/udev/links/webcam1' link_update: creating link '/dev/webcam1' to '/dev/video1' node_symlink: preserve already existing symlink '/dev/webcam1' to 'video1' udev_device_update_db: created db file '/run/udev/data/c81:1' for '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1' ACTION=add COLORD_DEVICE=1 COLORD_KIND=camera DEVLINKS=/dev/v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0 /dev/v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0 /dev/webcam1 DEVNAME=/dev/video1 DEVPATH=/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1 ID_BUS=usb ID_MODEL=08b0 ID_MODEL_ENC=08b0 ID_MODEL_ID=08b0 ID_PATH=pci-0000:00:1d.0-usb-0:2:1.0 ID_PATH_TAG=pci-0000_00_1d_0-usb-0_2_1_0 ID_REVISION=0002 ID_SERIAL=046d_08b0_01402100A5000000 ID_SERIAL_SHORT=01402100A5000000 ID_TYPE=generic ID_USB_DRIVER=Philips webcam ID_USB_INTERFACES=:0aff00:010100:010200: ID_USB_INTERFACE_NUM=00 ID_V4L_CAPABILITIES=:capture: ID_V4L_PRODUCT=Logitech QuickCam Pro 3000 ID_V4L_VERSION=2 ID_VENDOR=046d ID_VENDOR_ENC=046d ID_VENDOR_ID=046d MAJOR=81 MINOR=1 SUBSYSTEM=video4linux TAGS=:udev-acl: UDEV_LOG=6 USEC_INITIALIZED=18213768 run: 'udev-acl --action=add --device=/dev/video1' jjk@eee-old:~$ (and correspondingly for video2) It looks to me like my rules are read, but not respected. What am I doing wrong?

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  • Should we enforce code style in our large codebase?

    - by eighttrackmind
    By "code style" I mean 2 things: Style, eg. // bad if(foo){ ... } // good if (foo) { ... } Conventions and idiomaticity, where two ways of writing the same thing are functionally equivalent, but one is more idiomatic. eg. // bad if (fooLib.equals(a, b)) { ... } // good if (a == b) { ... } I think it makes sense to use an auto-formatter to enforce #1 automatically. So my question is specifically about #2. I like to break things down into pros and cons, here's what I've come up with so far: Pros: Used by many large codebases (eg. Google, jQuery) Helps make it a bit easier to work on new areas of the codebase Helps make code more portable (this is not necessarily true) Code style is automatic once you get used to it Makes it easier to fast-decline pull requests Cons: Takes engineers’ and code reviewers’ time away from more important things (like developing features) Code should ideally be rewritten every 2-3 years anyway, so it’s more important to focus on getting the architecture right, and achieving high test coverage Adds strain to code reviews (eg. “don’t do it this way, I like this other way better”) Even if I’ve been using a code style for a while, I still sometime have to pause and think about how to write a line better Having an enforced, uniform code style makes it hard to experiment with potentially better styles Maintaining a style guide takes a lot of incremental effort Engineers rarely read through the style guide. More often, it's cited in code reviews And as a secondary question: we also have many smaller repositories - should the same code style be enforced there?

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  • Is code maintenance typically a special project, or is it considered part of daily work?

    - by blueberryfields
    Earlier, I asked to find out which tools are commonly used to monitor methods and code bases, to find out whether the methods have been getting too long. Most of the responses there suggested that, beyond maintenance on the method currently being edited, programmers don't, in general, keep an eye on the rest of the code base. So I thought I'd ask the question in general: Is code maintenance, in general, considered part of your daily work? Do you find that you're spending at least some of your time cleaning up, refactoring, rewriting code in the code base, to improve it, as part of your other assigned work? Is it expected of you/do you expect it of your teammates? Or is it more common to find that cleanup, refactoring, and general maintenance on the codebase as a whole, occurs in bursts (for example, mostly as part of code reviews, or as part of refactoring/cleaning up projects)?

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  • How to fix Ogre3d segfault with std::_Rb_tree_insert_and_rebalance ?

    - by Balázs Béla
    Hello all. I'm working on a 3d music visualizer using Ogre3d, basically it's a spectrum analizer, a lot like the old xmms plugin: (http)://www.youtube.com/watch?v=_6NKBiwYN24 It works well, the bars are drawn and updated, there are no framerate issues, but it crashes randomly. Sometimes it can run without problems, finish the song, other times it crashes instantly, other times the music just stops, without a crash. Here is the source code for the main class : https://github.com/balazsbela/OgreVisualizer/blob/master/src/VisualizerApplication.cpp#L221 Also the crashes seem to happen less often when I display the framerate overlay from Ogre samples. Would limiting the framerate help ? The crashes are seemingly random. Is it a performance issue ? Please help me out, I'm quite lost on this one, I also posted on Ogre3d forums but I received no responses. (http)://www.ogre3d.org/forums/viewtopic.php?f=2&t=63207 I also tried stackoverflow: (http)://stackoverflow.com/questions/5050147/how-to-fix-ogre3d-segfault-with-std-rb-tree-insert-and-rebalance Thank you. Backtrace: balazsbela@darknet:~/workspace/OgreVisualizer/Release$ gdb OgreVisualizer core GNU gdb (GDB) 7.2-debian Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i486-linux-gnu". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /home/balazsbela/workspace/OgreVisualizer/Release/OgreVisualizer...done. [New Thread 17705] [New Thread 17702] [New Thread 17703] [New Thread 17700] Reading symbols from /usr/lib/libv4l/v4l1compat.so...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libv4l/v4l1compat.so Reading symbols from /usr/local/lib/libOgreMain.so.1.7.1...done. Loaded symbols for /usr/local/lib/libOgreMain.so.1.7.1 Reading symbols from /usr/lib/libfftw3.so.3...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libfftw3.so.3 Reading symbols from /usr/lib/libSDL_sound-1.0.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libSDL_sound-1.0.so.1 Reading symbols from /usr/lib/libSDL-1.2.so.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libSDL-1.2.so.0 Reading symbols from /usr/lib/libSDL_mixer-1.2.so.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libSDL_mixer-1.2.so.0 Reading symbols from /usr/lib/libOIS-1.2.0.so...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libOIS-1.2.0.so Reading symbols from /usr/lib/libstdc++.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libstdc++.so.6 Reading symbols from /lib/i686/cmov/libm.so.6...Reading symbols from /usr/lib/debug/lib/i686/cmov/libm-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libm.so.6 Reading symbols from /lib/libgcc_s.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libgcc_s.so.1 Reading symbols from /lib/i686/cmov/libc.so.6...Reading symbols from /usr/lib/debug/lib/i686/cmov/libc-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libc.so.6 Reading symbols from /lib/i686/cmov/libpthread.so.0...Reading symbols from /usr/lib/debug/lib/i686/cmov/libpthread-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libpthread.so.0 Reading symbols from /usr/local/lib/libv4l1.so.0...done. Loaded symbols for /usr/local/lib/libv4l1.so.0 Reading symbols from /usr/lib/libfreetype.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libfreetype.so.6 Reading symbols from /usr/lib/libSM.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libSM.so.6 Reading symbols from /usr/lib/libICE.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libICE.so.6 Reading symbols from /usr/lib/libX11.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libX11.so.6 Reading symbols from /usr/lib/libXext.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXext.so.6 Reading symbols from /usr/lib/libXt.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXt.so.6 Reading symbols from /usr/lib/libXaw.so.7...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXaw.so.7 Reading symbols from /lib/i686/cmov/libdl.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libdl-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libdl.so.2 Reading symbols from /usr/lib/libboost_thread.so.1.42.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libboost_thread.so.1.42.0 Reading symbols from /usr/lib/libboost_date_time.so.1.42.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libboost_date_time.so.1.42.0 Reading symbols from /usr/lib/libfreeimage.so.3...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libfreeimage.so.3 Reading symbols from /usr/lib/libzzip-0.so.13...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libzzip-0.so.13 Reading symbols from /usr/lib/libz.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libz.so.1 Reading symbols from /usr/lib/libsmpeg-0.4.so.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libsmpeg-0.4.so.0 Reading symbols from /usr/lib/libmikmod.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libmikmod.so.2 Reading symbols from /usr/lib/libvorbis.so.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libvorbis.so.0 Reading symbols from /usr/lib/libvorbisfile.so.3...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libvorbisfile.so.3 Reading symbols from /usr/lib/libFLAC.so.8...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libFLAC.so.8 Reading symbols from /usr/lib/libogg.so.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libogg.so.0 Reading symbols from /usr/lib/sse2/libspeex.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/sse2/libspeex.so.1 Reading symbols from /usr/lib/libasound.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libasound.so.2 Reading symbols from /lib/i686/cmov/librt.so.1...Reading symbols from /usr/lib/debug/lib/i686/cmov/librt-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/librt.so.1 Reading symbols from /usr/lib/libdirectfb-1.2.so.9...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libdirectfb-1.2.so.9 Reading symbols from /usr/lib/libfusion-1.2.so.9...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libfusion-1.2.so.9 Reading symbols from /usr/lib/libdirect-1.2.so.9...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libdirect-1.2.so.9 Reading symbols from /usr/lib/libvga.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libvga.so.1 Reading symbols from /lib/ld-linux.so.2...Reading symbols from /usr/lib/debug/lib/ld-2.11.2.so...done. done. Loaded symbols for /lib/ld-linux.so.2 Reading symbols from /usr/local/lib/libv4l2.so.0...done. Loaded symbols for /usr/local/lib/libv4l2.so.0 Reading symbols from /lib/libuuid.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libuuid.so.1 Reading symbols from /usr/lib/libxcb.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libxcb.so.1 Reading symbols from /usr/lib/libXmu.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXmu.so.6 Reading symbols from /usr/lib/libXpm.so.4...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXpm.so.4 Reading symbols from /usr/lib/libjpeg.so.62...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libjpeg.so.62 Reading symbols from /usr/lib/libmng.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libmng.so.1 Reading symbols from /usr/lib/libopenjpeg.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libopenjpeg.so.2 Reading symbols from /lib/libpng12.so.0...(no debugging symbols found)...done. Loaded symbols for /lib/libpng12.so.0 Reading symbols from /usr/lib/libIlmImf.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libIlmImf.so.6 Reading symbols from /usr/lib/libImath.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libImath.so.6 Reading symbols from /usr/lib/libHalf.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libHalf.so.6 Reading symbols from /usr/lib/libIex.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libIex.so.6 Reading symbols from /usr/lib/libIlmThread.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libIlmThread.so.6 Reading symbols from /lib/libx86.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libx86.so.1 Reading symbols from /usr/local/lib/libv4lconvert.so.0...done. Loaded symbols for /usr/local/lib/libv4lconvert.so.0 Reading symbols from /usr/lib/libXau.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXau.so.6 Reading symbols from /usr/lib/libXdmcp.so.6...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXdmcp.so.6 Reading symbols from /usr/lib/liblcms.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/liblcms.so.1 Reading symbols from /usr/local/lib/OGRE/RenderSystem_GL.so...done. Loaded symbols for /usr/local/lib/OGRE/RenderSystem_GL.so Reading symbols from /usr/lib/libGLU.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libGLU.so.1 Reading symbols from /usr/lib/libGL.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libGL.so.1 Reading symbols from /usr/lib/libXrandr.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXrandr.so.2 Reading symbols from /usr/lib/libGLcore.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libGLcore.so.1 Reading symbols from /usr/lib/tls/libnvidia-tls.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/tls/libnvidia-tls.so.1 Reading symbols from /usr/lib/libXrender.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXrender.so.1 Reading symbols from /usr/lib/libXcursor.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXcursor.so.1 Reading symbols from /usr/lib/libXfixes.so.3...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libXfixes.so.3 Reading symbols from /lib/i686/cmov/libnss_compat.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnss_compat-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libnss_compat.so.2 Reading symbols from /lib/i686/cmov/libnsl.so.1...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnsl-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libnsl.so.1 Reading symbols from /lib/i686/cmov/libnss_nis.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnss_nis-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libnss_nis.so.2 Reading symbols from /lib/i686/cmov/libnss_files.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnss_files-2.11.2.so...done. done. Loaded symbols for /lib/i686/cmov/libnss_files.so.2 Reading symbols from /usr/lib/alsa-lib/libasound_module_rate_speexrate.so...(no debugging symbols found)...done. Loaded symbols for /usr/lib/alsa-lib/libasound_module_rate_speexrate.so Reading symbols from /usr/lib/sse2/libspeexdsp.so.1...(no debugging symbols found)...done. Loaded symbols for /usr/lib/sse2/libspeexdsp.so.1 Core was generated by `./OgreVisualizer'. Program terminated with signal 11, Segmentation fault. #0 0xb6dc563d in std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&) () from /usr/lib/libstdc++.so.6 (gdb) bt #0 0xb6dc563d in std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&) () from /usr/lib/libstdc++.so.6 #1 0xb73bb3c2 in std::_Rb_tree<Ogre::Node*, Ogre::Node*, std::_Identity<Ogre::Node*>, std::less<Ogre::Node*>, Ogre::STLAllocator<Ogre::Node*, Ogre::CategorisedAllocPolicy<(Ogre::MemoryCategory)0> > >::_M_insert_(std::_Rb_tree_node_base const*, std::_Rb_tree_node_base const*, Ogre::Node* const&) () from /usr/local/lib/libOgreMain.so.1.7.1 #2 0xb73b5a52 in _M_insert_unique (this=0xb6157ea0, child=0xb616aff8, forceParentUpdate=false) at /usr/include/c++/4.4/bits/stl_tree.h:1182 #3 insert (this=0xb6157ea0, child=0xb616aff8, forceParentUpdate=false) at /usr/include/c++/4.4/bits/stl_set.h:411 #4 Ogre::Node::requestUpdate (this=0xb6157ea0, child=0xb616aff8, forceParentUpdate=false) at /home/balazsbela/Downloads/ogre_src_v1-7-1/OgreMain/src/OgreNode.cpp:805 #5 0xb73b6a40 in Ogre::Node::needUpdate (this=0xb616aff8, forceParentUpdate=92) at /home/balazsbela/Downloads/ogre_src_v1-7-1/OgreMain/src/OgreNode.cpp:789 #6 0xb73b5038 in Ogre::Node::setScale (this=0x1825c, scale=...) at /home/balazsbela/Downloads/ogre_src_v1-7-1/OgreMain/src/OgreNode.cpp:638 #7 0x0805d306 in VisualizerApplication::adjustNodes (this=0x9cd4808) at ../src/VisualizerApplication.cpp:236 #8 0xb6e867f0 in ?? () from /usr/lib/libSDL_mixer-1.2.so.0 #9 0xb6e8719a in ?? () from /usr/lib/libSDL_mixer-1.2.so.0 #10 0xb6ed9b0d in ?? () from /usr/lib/libSDL-1.2.so.0 #11 0xb6ee185e in ?? () from /usr/lib/libSDL-1.2.so.0 #12 0xb6f2e0bd in ?? () from /usr/lib/libSDL-1.2.so.0 #13 0xb6bc7955 in start_thread (arg=0xb198ab70) at pthread_create.c:300 #14 0xb6ca6e7e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130 (gdb) Ogre.log: (http)://pastie.org/1581790

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  • Copyrights concerning code snippets and larger amounts of code

    - by JustcallmeDrago
    I am designing a public code repository. Users will be allowed to post and edit whatever amount of code they want, from code snippets to entire multi-file projects. I have a few major legal concerns about this: Not getting sued/shut down - I feel the site would be a much easier target than tracking down an individual user to sue. I have looked around a bit and see links to legal info in the footer of each page is common. What specific things should I do--and what does does a site such as YouTube (which I see copyrighted material on all the time) do--for protection? Citing sources and editing sourced code - If a user wants to post code that isn't theirs, what concerns/safeguards should I have? Will a link suffice, and what do I need further to allow the code to be edited (to improve it for example)? What can happen if a user posts copyrighted code without citing it? Large chunks of code - What legal differences should I look out for as the amount grows? Not having a mess of licenses for the site - I would like to have a single license (like RosettaCode) that keeps things simple for interaction on the site. I want the code to be postable and editable. I have looked into StackOverflow's CreativeCommons license a little and it says that If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one. And on RosettaCode: All software found on Rosetta Code should be considered potentially hazardous. Use at your own risk. Be aware that all code on Rosetta Code is under the GNU Free Documentation License, as are any edits made by contributors. See Rosetta Code:Copyrights for details. What other licenses are like this? Commercializing the site - In what ways can I and can't I make money off of a site that contains code like this? All code will be publicly visible. Initial thoughts are having ads or making money by charging for advanced features.

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  • Design by Contract with Microsoft .Net Code Contract

    - by Fredrik N
    I have done some talks on different events and summits about Defensive Programming and Design by Contract, last time was at Cornerstone’s Developer Summit 2010. Next time will be at SweNug (Sweden .Net User Group). I decided to write a blog post about of some stuffs I was talking about. Users are a terrible thing! Protect your self from them ”Human users have a gift for doing the worst possible thing at the worst possible time.” – Michael T. Nygard, Release It! The kind of users Michael T. Nygard are talking about is the users of a system. We also have users that uses our code, the users I’m going to focus on is the users of our code. Me and you and another developers. “Any fool can write code that a computer can understand. Good programmers write code that humans can understand.” – Martin Fowler Good programmers also writes code that humans know how to use, good programmers also make sure software behave in a predictable manner despise inputs or user actions. Design by Contract   Design by Contract (DbC) is a way for us to make a contract between us (the code writer) and the users of our code. It’s about “If you give me this, I promise to give you this”. It’s not about business validations, that is something completely different that should be part of the domain model. DbC is to make sure the users of our code uses it in a correct way, and that we can rely on the contract and write code in a way where we know that the users will follow the contract. It will make it much easier for us to write code with a contract specified. Something like the following code is something we may see often: public void DoSomething(Object value) { value.DoIKnowThatICanDoThis(); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Where “value” can be uses directly or passed to other methods and later be used. What some of us can easily forget here is that the “value” can be “null”. We will probably not passing a null value, but someone else that uses our code maybe will do it. I think most of you (including me) have passed “null” into a method because you don’t know if the argument need to be specified to a valid value etc. I bet most of you also have got the “Null reference exception”. Sometimes this “Null reference exception” can be hard and take time to fix, because we need to search among our code to see where the “null” value was passed in etc. Wouldn’t it be much better if we can as early as possible specify that the value can’t not be null, so the users of our code also know it when the users starts to use our code, and before run time execution of the code? This is where DbC comes into the picture. We can use DbC to specify what we need, and by doing so we can rely on the contract when we write our code. So the code above can actually use the DoIKnowThatICanDoThis() method on the value object without being worried that the “value” can be null. The contract between the users of the code and us writing the code, says that the “value” can’t be null.   Pre- and Postconditions   When working with DbC we are specifying pre- and postconditions.  Precondition is a condition that should be met before a query or command is executed. An example of a precondition is: “The Value argument of the method can’t be null”, and we make sure the “value” isn’t null before the method is called. Postcondition is a condition that should be met when a command or query is completed, a postcondition will make sure the result is correct. An example of a postconditon is “The method will return a list with at least 1 item”. Commands an Quires When using DbC, we need to know what a Command and a Query is, because some principles that can be good to follow are based on commands and queries. A Command is something that will not return anything, like the SQL’s CREATE, UPDATE and DELETE. There are two kinds of Commands when using DbC, the Creation commands (for example a Constructor), and Others. Others can for example be a Command to add a value to a list, remove or update a value etc. //Creation commands public Stack(int size) //Other commands public void Push(object value); public void Remove(); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   A Query, is something that will return something, for example an Attribute, Property or a Function, like the SQL’s SELECT.   There are two kinds of Queries, the Basic Queries  (Quires that aren’t based on another queries), and the Derived Queries, queries that is based on another queries. Here is an example of queries of a Stack: //Basic Queries public int Count; public object this[int index] { get; } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } To understand about some principles that are good to follow when using DbC, we need to know about the Commands and different Queries. The 6 Principles When working with DbC, it’s advisable to follow some principles to make it easier to define and use contracts. The following DbC principles are: Separate commands and queries. Separate basic queries from derived queries. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries. For each command, write a postcondition that specifies the value of every basic query. For every query and command, decide on a suitable precondition. Write invariants to define unchanging properties of objects. Before I will write about each of them I want you to now that I’m going to use .Net 4.0 Code Contract. I will in the rest of the post uses a simple Stack (Yes I know, .Net already have a Stack class) to give you the basic understanding about using DbC. A Stack is a data structure where the first item in, will be the first item out. Here is a basic implementation of a Stack where not contract is specified yet: public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } //Is related to Count and this[] Query public object Top() { return this[Count]; } //Creation commands public Stack(uint size) { Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { this[++Count] = value; } public void Remove() { this[Count] = null; Count--; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The Stack is implemented in a way to demonstrate the use of Code Contract in a simple way, the implementation may not look like how you would implement it, so don’t think this is the perfect Stack implementation, only used for demonstration.   Before I will go deeper into the principles I will simply mention how we can use the .Net Code Contract. I mention before about pre- and postcondition, is about “Require” something and to “Ensure” something. When using Code Contract, we will use a static class called “Contract” and is located in he “System.Diagnostics.Contracts” namespace. The contract must be specified at the top or our member statement block. To specify a precondition with Code Contract we uses the Contract.Requires method, and to specify a postcondition, we uses the Contract.Ensure method. Here is an example where both a pre- and postcondition are used: public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The contract above requires that the Count is greater than 0, if not we can’t get the item at the Top of a Stack. We also Ensures that the results (By using the Contract.Result method, we can specify a postcondition that will check if the value returned from a method is correct) of the Top query is equal to this[Count].   1. Separate Commands and Queries   When working with DbC, it’s important to separate Command and Quires. A method should either be a command that performs an Action, or returning information to the caller, not both. By asking a question the answer shouldn’t be changed. The following is an example of a Command and a Query of a Stack: public void Push(object value) public object Top() .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The Push is a command and will not return anything, just add a value to the Stack, the Top is a query to get the item at the top of the stack.   2. Separate basic queries from derived queries There are two different kinds of queries,  the basic queries that doesn’t rely on another queries, and derived queries that uses a basic query. The “Separate basic queries from derived queries” principle is about about that derived queries can be specified in terms of basic queries. So this principles is more about recognizing that a query is a derived query or a basic query. It will then make is much easier to follow the other principles. The following code shows a basic query and a derived query: //Basic Queries public uint Count; //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   We can see that IsEmpty will use the Count query, and that makes the IsEmpty a Derived query.   3. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries.   When the derived query is recognize we can follow the 3ed principle. For each derived query, we can create a postcondition that specifies what result our derived query will return in terms of one or more basic queries. Remember that DbC is about contracts between the users of the code and us writing the code. So we can’t use demand that the users will pass in a valid value, we must also ensure that we will give the users what the users wants, when the user is following our contract. The IsEmpty query of the Stack will use a Count query and that will make the IsEmpty a Derived query, so we should now write a postcondition that specified what results will be returned, in terms of using a basic query and in this case the Count query, //Basic Queries public uint Count; //Derived Queries public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } The Contract.Ensures is used to create a postcondition. The above code will make sure that the results of the IsEmpty (by using the Contract.Result to get the result of the IsEmpty method) is correct, that will say that the IsEmpty will be either true or false based on Count is equal to 0 or not. The postcondition are using a basic query, so the IsEmpty is now following the 3ed principle. We also have another Derived Query, the Top query, it will also need a postcondition and it uses all basic queries. The Result of the Top method must be the same value as the this[] query returns. //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count and this[] Query public object Top() { Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   4. For each command, write a postcondition that specifies the value of every basic query.   For each command we will create a postconditon that specifies the value of basic queries. If we look at the Stack implementation we will have three Commands, one Creation command, the Constructor, and two others commands, Push and Remove. Those commands need a postcondition and they should include basic query to follow the 4th principle. //Creation commands public Stack(uint size) { Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   As you can see the Create command will Ensures that Count will be 0 when the Stack is created, when a Stack is created there shouldn’t be any items in the stack. The Push command will take a value and put it into the Stack, when an item is pushed into the Stack, the Count need to be increased to know the number of items added to the Stack, and we must also make sure the item is really added to the Stack. The postconditon of the Push method will make sure the that old value of the Count (by using the Contract.OldValue we can get the value a Query has before the method is called)  plus 1 will be equal to the Count query, this is the way we can ensure that the Push will increase the Count with one. We also make sure the this[] query will now contain the item we pushed into the Stack. The Remove method must make sure the Count is decreased by one when the top item is removed from the Stack. The Commands is now following the 4th principle, where each command now have a postcondition that used the value of basic queries. Note: The principle says every basic Query, the Remove only used one Query the Count, it’s because this command can’t use the this[] query because an item is removed, so the only way to make sure an item is removed is to just use the Count query, so the Remove will still follow the principle.   5. For every query and command, decide on a suitable precondition.   We have now focused only on postcondition, now time for some preconditons. The 5th principle is about deciding a suitable preconditon for every query and command. If we starts to look at one of our basic queries (will not go through all Queries and commands here, just some of them) the this[] query, we can’t pass an index that is lower then 1 (.Net arrays and list are zero based, but not the stack in this blog post ;)) and the index can’t be lesser than the number of items in the stack. So here we will need a preconditon. public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Think about the Contract as an documentation about how to use the code in a correct way, so if the contract could be specified elsewhere (not part of the method body), we could simply write “return _array[index]” and there is no need to check if index is greater or lesser than Count, because that is specified in a “contract”. The implementation of Code Contract, requires that the contract is specified in the code. As a developer I would rather have this contract elsewhere (Like Spec#) or implemented in a way Eiffel uses it as part of the language. Now when we have looked at one Query, we can also look at one command, the Remove command (You can see the whole implementation of the Stack at the end of this blog post, where precondition is added to more queries and commands then what I’m going to show in this section). We can only Remove an item if the Count is greater than 0. So we can write a precondition that will require that Count must be greater than 0. public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   6. Write invariants to define unchanging properties of objects.   The last principle is about making sure the object are feeling great! This is done by using invariants. When using Code Contract we can specify invariants by adding a method with the attribute ContractInvariantMethod, the method must be private or public and can only contains calls to Contract.Invariant. To make sure the Stack feels great, the Stack must have 0 or more items, the Count can’t never be a negative value to make sure each command and queries can be used of the Stack. Here is our invariant for the Stack object: [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The ObjectInvariant method will be called every time after a Query or Commands is called. Here is the full example using Code Contract:   public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } set { Contract.Requires(index >= 1); Contract.Requires(index <= Count); _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } //Is related to Count and this[] Query public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } //Creation commands public Stack(uint size) { Contract.Requires(size > 0); Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Requires(value != null); Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Summary By using Design By Contract we can make sure the users are using our code in a correct way, and we must also make sure the users will get the expected results when they uses our code. This can be done by specifying contracts. To make it easy to use Design By Contract, some principles may be good to follow like the separation of commands an queries. With .Net 4.0 we can use the Code Contract feature to specify contracts.

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  • Can notes/to-dos in code comments sent to code-reviews result in an effective refactoring process?

    - by dukeofgaming
    I want to start/improve a culture of collective code ownership at my company but at a geographically distributed level... I'd say there is some current collective code-ownership mentality, but only at single geographical sites. This is a follow-up to this question: What is the politically correct way of refactoring other's code? I'm just wondering if submitting *just code comments* for code reviews (we have ReviewBoard, possibly upgrading to Crucible) could actually be an effective mechanism to get the conversation started on improving code, without having others feel territorial about their code. For example, if I add: //ToDo: Refactor this code and that code because of reasons X and Y Then, submit it for code review, and it gets accepted... it could be considered as an agreement (which I think is sometimes harder to get with new code up front). At the same time, the author (and others) might have an easier time digesting and accepting the proposal; rejecting a proposal because it might break things will not longer be a valid reason and therefore the fear of making a change is lost... and at the same time, do not invest 10 hours optimizing something that no one thinks it is worth it and opposes to it just out of fear. This is all conjecture, but I'm feeling something like this (submitting refactoring notes in code comments at the code-review process) would work. Has anyone done something like this in practice?, if so, what have been the results?

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  • Writing/discussions about the aesthetics of code?

    - by dilettante.coder
    I'm looking for considerations of the questions "Can code be beautiful?" and "What makes code beautiful?" Examples would include: This academic paper: Obfuscation, Weird Languages, and Code Aesthetics This blog post: Hamon or the Skin Deep Beauty of Code Please note that I'm not trying to start a discussion here, or asking for opinions about what makes code beautiful, or for code you think is beautiful; I'm trying to find stuff that has already been published. Thanks for your help.

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  • Do abstractions have to reduce code readability?

    - by Martin Blore
    A good developer I work with told me recently about some difficulty he had in implementing a feature in some code we had inherited; he said the problem was that the code was difficult to follow. From that, I looked deeper into the product and realised how difficult it was to see the code path. It used so many interfaces and abstract layers, that trying to understand where things began and ended was quite difficult. It got me thinking about the times I had looked at past projects (before I was so aware of clean code principles) and found it extremely difficult to get around in the project, mainly because my code navigation tools would always land me at an interface. It would take a lot of extra effort to find the concrete implementation or where something was wired up in some plugin type architecture. I know some developers strictly turn down dependency injection containers for this very reason. It confuses the path of the software so much that the difficulty of code navigation is exponentially increased. My question is: when a framework or pattern introduces so much overhead like this, is it worth it? Is it a symptom of a poorly implemented pattern? I guess a developer should look to the bigger picture of what that abstractions brings to the project to help them get through the frustration. Usually though, it's difficult to make them see that big picture. I know I've failed to sell the needs of IOC and DI with TDD. For those developers, use of those tools just cramps code readability far too much.

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  • Please recommend citations for source code documentation standards

    - by Aerik
    I'm trying to convince another group in my company that they need to provide more documentation in their source code (they want to hand off the code to my group) but they're treating it as a "nice to have". In my view, it's a necessity. I've run a source code analysis tool and it's showing about 10% comment lines - but looking at the source code, most of that is coming from entire functions that the author has commented out. Can anyone provide some authoritative citations / references for documentation / comment standards for source code? (In case it matters, we're a C# house, with a little Matlab thrown in).

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  • Does code-generation increase the code quality?

    - by platzhirsch
    Arguing for code-generation I am looking for some reasons, if howsoever, code generation increases the code quality, respectively is in favor for quality insurance. To clarify what I mean with code-generation I can talk only about a project of mine: We use XML files to describe different relationships, in fact our database schema. These XML files are used to generate our ORM framework and HTML forms which can be used to add, delete and modify entities. To my mind, it increases the quality, as the human error is reduced. If someone was implemented wrong, it is broken in the model. This is good, because the error might appear a lot faster, as more generated code is broken, too.

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  • How to measure code quality? [closed]

    - by Lo Wai Lun
    Is there a methodology or any objective standard to determine whether the code of the project is well-written? How to measure in a structural and scientific manner to access the quality of the code? Many people say code review is important and always do encapsulation and data abstraction to ensure the quality. How can we determine the quality? Can a structural, organised software design diagrams drawn implies good quality of code ? If we type the code with good cautions of encapsulation and data abstraction, why review anyway?

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  • c# reading integer fields from database, returning empty string when reading integer type field

    - by arnoldino
    what is wrong with this code? field="id"; table="MInvMonth"; condition="machine_id=37"; public static String getConditionedField(String field, String table, String condition) try { if (cmd == null) getConnection(); cmd.CommandText = "Select " + field + " from " + table + " where " + condition; SQLiteDataReader reader = cmd.ExecuteReader(); if (reader.HasRows==true) { reader.Read(); string s = reader[0].ToString(); // return first element reader.Close(); return s; } reader.Close(); return null; } catch (Exception e) { MessageBox.Show("Caught exception: " + e.Message+"|"+cmd.CommandText); return null; } I checked the sql statement, it turns the right value. why can't I read it? the returnvalue is "".

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  • How to read Scala code with lots of implicits?

    - by Petr Pudlák
    Consider the following code fragment (adapted from http://stackoverflow.com/a/12265946/1333025): // Using scalaz 6 import scalaz._, Scalaz._ object Example extends App { case class Container(i: Int) def compute(s: String): State[Container, Int] = state { case Container(i) => (Container(i + 1), s.toInt + i) } val d = List("1", "2", "3") type ContainerState[X] = State[Container, X] println( d.traverse[ContainerState, Int](compute) ! Container(0) ) } I understand what it does on high level. But I wanted to trace what exactly happens during the call to d.traverse at the end. Clearly, List doesn't have traverse, so it must be implicitly converted to another type that does. Even though I spent a considerable amount of time trying to find out, I wasn't very successful. First I found that there is a method in scalaz.Traversable traverse[F[_], A, B] (f: (A) => F[B], t: T[A])(implicit arg0: Applicative[F]): F[T[B]] but clearly this is not it (although it's most likely that "my" traverse is implemented using this one). After a lot of searching, I grepped scalaz source codes and I found scalaz.MA's method traverse[F[_], B] (f: (A) => F[B])(implicit a: Applicative[F], t: Traverse[M]): F[M[B]] which seems to be very close. Still I'm missing to what List is converted in my example and if it uses MA.traverse or something else. The question is: What procedure should I follow to find out what exactly is called at d.traverse? Having even such a simple code that is so hard analyze seems to me like a big problem. Am I missing something very simple? How should I proceed when I want to understand such code that uses a lot of imported implicits? Is there some way to ask the compiler what implicits it used? Or is there something like Hoogle for Scala so that I can search for a method just by its name?

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  • Reading Open Source Projects

    - by Hossein
    About my programming knowledge: I have basic knowledge of programming. Have never worked in a team project. Have done, only, a couple of small solo projects. Problem: Consider a typical open source project. We want to know about the project, so that we can contribute, test it, just out of curiosity, etc. The documentations do not describe the code architecture, usually, so RTFM(!) wouldn't apply here. They usually tend to describe how to use the software, not how it is designed. Mailing Lists in big projects are very crowded. Tens of e-mails are send in just an hour. also, following the mailing list to know the project is like understanding a film when you have arrived late, when half of the film is gone or even worse. Obviously, the code is not like a novel. So, you can't start from downloading the source code and just "start from the first page and so on"! Question: How should one understand open source project? What are the steps to do in an open source project, to understand how the whole thing works and get into speed with the "under the hood"?

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  • Review quality of code

    - by magol
    I have been asked to quality review two code bases. I've never done anything like that, and need advice on how to perform it and report it. Background There are two providers of code, one in VB and one in C (ISO 9899:1999 (C99)). These two programs do not work so well together, and of course, the two suppliers blames each other. I will therefore as a independent person review both codes, on a comprehensive level review the quality of the codes to find out where it is most likely that the problem lies. I will not try to find problems, but simply review the quality and how simple it is to manage and understand the code. Edit: I have yet not received much information about what the problem consists of. I've just been told that I will examine the code in terms of quality. Not so much more. I do not know the background to why they took this decision.

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  • Is Code Complete still Code Complete? [closed]

    - by Peter Turner
    It's been quite a few years since Code Complete was published. I really love the book, I keep it in the bathroom at the office and read a little out of it once or twice a day. But I don't think it's possible to call Code Complete, "Code Complete" when it doesn't have language features that even Delphi has, like anonymous methods and generics. What key sections are missing from this book, and what should be deprecated?

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  • How to Code Faster (Without Sacrificing Quality)

    - by ashes999
    I've been a professional coder for a several years. The comments about my code have generally been the same: writes great code, well-tested, but could be faster. So how do I become a faster coder, without sacrificing quality? For the sake of this question, I'm going to limit the scope to C#, since that's primarily what I code (for fun) -- or Java, which is similar enough in many ways that matter. Things that I'm already doing: Write the minimal solution that will get the job done Write a slew of automated tests (prevents regressions) Write (and use) reusable libraries for all kinds of things Use well-known technologies where they work well (eg. Hibernate) Use design patterns where they fit into place (eg. Singleton) These are all great, but I don't feel like my speed is increasing over time. I do care, because if I can do something to increase my productivity (even by 10%), that's 10% faster than my competitors. (Not that I have any.) Besides which, I've consistently gotten this feeback from my managers -- whether it was small-scale Flash development or enterprise Java/C++ development. Edit: There seem to be a lot of questions about what I mean by fast, and how I know I'm slow. Let me clarify with some more details. I worked in small and medium-sized teams (5-50 people) in various companies over various projects and various technologies (Flash, ASP.NET, Java, C++). The observation of my managers (which they told me directly) is that I'm "slow." Part of this is because a significant number of my peers sacrificed quality for speed; they wrote code that was buggy, hard to read, hard to maintain, and difficult to write automated tests for. My code generally is well-documented, readable, and testable. At Oracle, I would consistently solve bugs slower than other team-members. I know this, because I would get comments to that effect; this means that other (yes, more senior and experienced) developers could do my work in less time than it took me, at nearly the same quality (readability, maintainability, and testability). Why? What am I missing? How can I get better at this? My end goal is simple: if I can make product X in 40 hours today, and I can improve myself somehow so that I can create the same product at 20, 30, or even 38 hours tomorrow, that's what I want to know -- how do I get there? What process can I use to continually improve? I had thought it was about reusing code, but that's not enough, it seems.

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  • Picking a code review tool

    - by marcog
    We are a startup looking to migrate from Fogbugz/Kiln to a new issue tracker/code review system. We are very happy with Jira, especially the configurability, but we are undecided on a code review tool. We have been trialing Bitbucket, but it doesn't fit our workflow well. Here are the problems we have identified with BB: Comments can be hard to find: when commenting on code not visible in the diff when code that is commented on is later changed viewing the full file doesn't include comments (also doesn't show changes) Viewing comments on individual commits can be a pain We have the implementer merge the diff and close the issue, whereas pull requests are more suited to the open source model where someone with commit rights merges We would like to automate creation of the code review (either from Jira or a command line tool) No syntax highlighting Once the pull request exceeds a certain size, BB won't show the whole thing and you have to view individual commits Linking BB pull requests to Jira issues is a bit janky: we have a pull request URL field on Jira, but this doesn't work when there are changes in multiple repositories Does anyone have any good suggestion given the above? We are tight on budget, and Jira integration is a big plus. We also have multiple commits per issue, and would like to have the option of viewing individual commits in the review. It might also be worth noting that we have a separate reviewer and tester for each issue.

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  • Code Golf: Code 39 Bar Code

    - by gwell
    The challenge The shortest code by character count to draw an ASCII representation of a Code 39 bar code. Wikipedia article about Code 39: http://en.wikipedia.org/wiki/Code_39 Input The input will be a string of legal characters for Code 39 bar codes. This means 43 characters are valid: 0-9 A-Z (space) and -.$/+%. The * character will not appear in the input as it is used as the start and stop characters. Output Each character encoded in Code 39 bar codes have nine elements, five bars and four spaces. Bars will be represented with # characters, and spaces will be represented with the space character. Three of the nine elements will be wide. The narrow elements will be one character wide, and the wide elements will be three characters wide. A inter-character space of a single space should be added between each character pattern. The pattern should be repeated so that the height of the bar code is eight characters high. The start/stop character * (bWbwBwBwb) would be represented like this: # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # # # ### ### # ^ ^ ^^ ^ ^ ^ ^^^ | | || | | | ||| narrow bar -+ | || | | | ||| wide space ---+ || | | | ||| narrow bar -----+| | | | ||| narrow space ------+ | | | ||| wide bar --------+ | | ||| narrow space ----------+ | ||| wide bar ------------+ ||| narrow space --------------+|| narrow bar ---------------+| inter-character space ----------------+ The start and stop character * will need to be output at the start and end of the bar code. No quiet space will need to be included before or after the bar code. No check digit will need to be calculated. Full ASCII Code39 encoding is not required, just the standard 43 characters. No text needs to be printed below the ASCII bar code representation to identify the output contents. The character # can be replaced with another character of higher density if wanted. Using the full block character U+2588, would allow the bar code to actually scan when printed. Test cases Input: ABC Output: # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # # # ### ### # ### # # # ### # ### # # ### ### ### # # # # # ### ### # Input: 1/3 Output: # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # # # ### ### # ### # # # ### # # # # # ### ### # # # # # ### ### # Input: - $ (minus space dollar) Output: # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # # # ### ### # # # # ### ### # ### # ### # # # # # # # # ### ### # Code count includes input/output (full program).

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