The Require Method in Ruby

In order to create reusable components, ones that can be easily used in other programs, a programming language must have some way of smoothly importing that code at run-time. In Ruby, the require method is used to load another file and execute all its statements. This serves to import all class and method definitions in the file. In addition to simply executing all of the statements in the file, the require method also keeps track of which files have been previously required and, thus, will not require a file twice. Using the 'require' Method The require method takes the name of the file to require, as a string, as a single argument. This can either be a path to the file, such as ./lib/some_library.rb or a shortened name, such as some_library. If the argument is a path and complete filename, the require method will look there for the file. However, if the argument is a shortened name, the require method will search through a number of pre-defined directories on your system for that file. Using the shortened name is the most common way of using the require method. The following example demonstrates how to use the require statement. The file test_library.rb is in the first code block. This file prints a message and defines a new class. The second code block is the file test_program.rb. This file loads the test_library.rb file using the require method and creates a new TestClass object. puts test_library includedclass TestClassdef initializeputs TestClass object createdendend #!/usr/bin/env rubyrequire test_library.rbt TestClass.new Avoid Name Clashes When writing reusable components, its best not to declare many variables in the global scope outside any classes or methods or by using the $ prefix. This is to prevent something called namespace pollution. If you declare too many names, another program or library might declare the same name and cause a name clash. When two completely unrelated libraries start changing each others variables accidentally, things will break-- seemingly at random. This is a very difficult bug to track down and its best just to avoid it. To avoid name clashes, you can enclose everything in your library inside of a module statement. This will require people to refer to your classes and method by a fully qualified name such as MyLibrary::my_method, but its worth it since name clashes generally wont occur. For people who want to have all of your class and method names in the global scope, they can do that using the include statement. The following example repeats the previous example but encloses everything in a MyLibrary module. Two versions of my_program.rb are given; one that uses the include statement and one that does not. puts test_library includedmodule MyLibraryclass TestClassdef initializeputs TestClass object createdendendend #!/usr/bin/env rubyrequire test_library2.rbt MyLibrary::TestClass.new #!/usr/bin/env rubyrequire test_library2.rbinclude MyLibraryt TestClass.new Avoid Absolute Paths Because reusable components often get moved around, its also best not to use absolute paths in your require calls. An absolute path is a path like /home/user/code/library.rb. Youll notice that the file must be in that exact location in order to work. If the script is ever moved or your home directory ever changes, that require statement will stop working. Instead of absolute paths, its often common to create a ./lib directory in your Ruby programs directory. The ./lib directory is added to the $LOAD_PATH variable which stores the directories in which the require method searches for Ruby files. After that, if the file my_library.rb is stored in the lib directory, it can be loaded into your program with a simple require my_library statement. The following example is the same as the previous test_program.rb examples. However, it assumes the test_library.rb file is stored in the ./lib directory and loads it using the method described above. #!/usr/bin/env ruby$LOAD_PATH ./librequire test_library.rbt TestClass.new

Because I Could Not Stop for Death - 700 Words

Read over Because I Could Not Stop for Death by Emily Dickinson. 1. List as many examples of metaphors and similes as possible. The carriage, in stanza 1, is a metaphor for a hearse. When they â€Å"passed the setting sun† (12) it implies that she has finally died. When they â€Å"paused before a house that seemed / A swelling of the ground† (17-18), the word house is a metaphor for grave. 2. Explain the personification. In Emily Dickinsons poem, â€Å"Because I Could Not Stop for Death†, death is personified in an unusual way. Instead of the expected dark, evil, Grim-reaper depiction of death, Dickinson portrayed him as more of a gentleman. Death became a character, able to carry out a human action, who â€Å"kindly stopped† (2) for the speaker,†¦show more content†¦Dickinsons use of diction in this case displayed the speakers calmness, even though she was looking at her own grave. Perhaps she was trying to tell the reader that death and the grave is not something to be feared. 2. At the start of the poem, the speaker told us how Death â€Å"kindly stopped for [her]† (2), and in a carriage no less. Following the theme of death and graves, the reader could perhaps surmise that this carriage symbolizes a hearse. However, this was no ordinary hearse. The speaker described how â€Å"The carriage held but just [themselves] / And Immortality† 3-4). The presence of Immortality transforms the carriage from an earthly, physical form of transportation into something more transcendental. In fact, this was confirmed in the final stanza of the poem, when she said that on the day of her death she â€Å"first surmised the horses heads / Were toward eternity† (23-24). The horses were, of course, the ones pulling the carriage, which means that the coach itself was headed toward eternity. Also, the use of the word carriage instead of hearse played into the personification of death as a gentleman or a suitor. 4. Discuss the poems meaning as best you can on your own without reviewing critical materials on-line or in books. What is most important is that you learn to develop your own critical eye, and your own ability to review poems for meaning. Your ideas and opinions matter, providedShow MoreRelated`` Because I Could Not Stop For Death ``880 Words   |  4 PagesDeath is an aspect of life that everyone becomes acquainted with sooner or later. The poem, â€Å"Because I Could Not Stop for Death,† by Emily Dickinson, is seen as a reflection of the passing of time in one s life while living. No one knows when it is their time to die, and we live everyday as if tomorrow it promised. Dickinson is saying that since we as humans tend to live on the expectation for tomorrow, we don t think about the end of our life or when it will be. That time will stand still whenRead MoreBecause I Could Not Stop for Death1444 Words   |  6 PagesBecause I could not stop for Death In Emily Dickinsons poem Because I could not stop for Death the main theme seems to be the acceptance of Death. Emily gives reference to the theme by using death in the first line. The poem is unique and interesting because she presents Death in a different way by referring to it as an escort taking her on a journey towards eternity rather than making it seem like something frightening. Each stanza of the poem breaks down the journey through the stagesRead More`` Because I Could Not Stop For Death ``1229 Words   |  5 PagesEveryone will die one day. It is a true, but unpleasant fact. Since death is therefore universal, it is easy to understand why a theme of death occurs so often in films and literature. Poetry is no exception to this trend. Poetry is filled with references to death or dying, as death is one of the most significant human conditions. A number of poets in particular have used death frequently in their writing. Emily Dickinson and Dylan Thomas are two of those poe ts. Emily Dickinson was born in 1830 andRead More`` Because I Could Not Stop For Death ``1354 Words   |  6 PagesBecause I could not stop for Death is one of the most puzzling poems Emily Dickinson wrote. â€Å"Scholars who stress these subversive qualities note that this poet appropriated conventional language, images, and themes and twisted them, disrupting their usual meaning.† (Dunlap, 2) In this poem, she describes death in hindsight. She commentates the experience play by play, chronicling her actions and vision from the time he arrived to pick her up in his carriage to her final resting place. In theRead More`` Because I Could Not Stop For Death ``876 Words   |  4 Pages We cannot leave death of death can â€Å"Because I could not stop for Death† by Emily Dickinson has written in 1863. Emily Dickinson was born in 1830-86, she is one of the greatest poets in American literature. Dickinson wrote love poems which it indicates strong attachment because of this it s difficult to know if does poems where subjects of her feelings or just part of her poetic imagination. The different tension that comes from her work is due to the cause of not accepting orthodox religion, â€Å"theRead MoreBecause I Could Not Stop For Death1886 Words   |  8 PagesEvery major religion has an answer to what is expect in death. However, contrary to major religious beliefs the reality is that no one knows when death will come or exactly what death entails - because those that die cannot communicate with the living. This is precisely the issue that Emily Dickinson tackles in her poem â€Å"Because I Could Not Stop for Death†. The speaker begins by offering a sanguine outlook in the eyes of death, however, the speaker eventually rejects her initial optimism. DickinsonRead MoreAnalysis Of Because I Could Not Stop For Death963 Words   |  4 Pagesâ€Å"Because I Could Not Stop For Death,† and â€Å"The Bustle in a House† are two poems by Emily Dickinson that portray death in very different ways. â€Å" Because I Could Not Stop For Death† is written from the perspective of a woman who has recently died about her eternal journey with a kind Death. â€Å"The Bustle in a House,† on the other hand, is about how one reacts to the death of a loved one. Through these two poems, Dickinson employs literary devices such as personification and metaphor to portray two differentRead MoreAnalysis Of `` Because I Could Not Stop For Death ``870 Words   |  4 PagesThemes of death all ring loud and clear in Dickinson’s â€Å"Because I could not stop for Death†, Donne’s â€Å"Death, be not proud†, and Cherry’s â€Å"Alzheimerâ₠¬â„¢s†. The poems are not explicitly about the act of dying, but death is personified or even foreshadowed in the work. Each piece has a different tone when referencing Death. Two of the poems reference Death by name, the last poem doesn’t specifically speak about dying or death per se, but based on the title, â€Å"Alzheimer’s†, it is clear that death is imminentRead MoreAnalysis of Because I Could Not Stop for Death2013 Words   |  9 PagesAnalysis of Because I Could Not Stop for Death The poets of the nineteenth century wrote on a variety of topics. One often used topic is that of death. The theme of death has been approached in many different ways. Emily Dickinson is one of the numerous poets who uses death as the subject of several of her poems. In her poem Because I Could Not Stop for Death, death is portrayed as a gentleman who comes to give the speaker a ride to eternity. Throughout the poem, Dickinson develops herRead MoreBecause I Could Not Stop Death By Emily Dickinson989 Words   |  4 PagesThe poem â€Å"Because I Could Not Stop Death† by Emily Dickinson is one of my favorite poems since high school. I chose this poem due to the fact that that Emily Dickinson is one of my favorite poets, I personally love her dark, and mysterious poems. Indeed, people believed she was a little messed up in the head, but I believe she was just misunderstood. Additionally, this poem definitely brought back terrifying memories. When couple years ago, I got into a horrible car accident with a drunk driver,

Broken window concept Free Essays

The â€Å"broken window† concept is among the most popular frameworks, designed for better understanding of the nature of crime and its prevention. George Kelling was the first criminologist, who suggested that even tiny problems are visible – for instance, a broken window points to the house owner’s ignorance and indifference. The paper is intended to discuss the concept and its application in details. We will write a custom essay sample on Broken window concept or any similar topic only for you Order Now â€Å"The essence of â€Å"broken windows† is that neighborhood disorder –physical decay, such as graffiti, litter and dilapidation; and minor misconduct, such as public drinking and vagrancy – will, if left unchecked, signal potential miscreants that no one is watching† (Miller, 2001, p. 27). This means, grave crimes begin with minor misdemeanors, and notorious criminals like serial killers often ‘begin with’ drug or alcohol abuse, which grow into social pathology, constantly reinforced by the conviction in the overall permissiveness (Miller, 2001). Conversely, when eliminating the traces of minor misconducts like litter and graffiti in public places, the visitors become more conscientious about the overall public safety in this place. At first, the concept was applied in subways: Bratton, who received a piece of â€Å"broken window† advice from Kelling and subsequently wrote: â€Å"Fare evasion was the biggest broken window in the transit system. We were going to fix that window and see that it didn’t get broken again† (Miller, 2001, p. 28). Thus, the group increased the number of policemen, supposed to detect the stowaway passengers – as a result, they found that a number of these ‘wrongdoers’ carried illegal arms and some of them had light drugs like marijuana. Finally, the subway became much cleaner and safer, as the number of combats and conflicts substantially decreased. Later, Mr. Bretton was hired as New York police commissioner, assigned to struggle with street prostitution. Violent and aggressive behavior and public drinking. The executive of the law enforcement agency introduced new computerized systems of surveillance in public places and increased the staff of the agency –as a result, the number of felony crimes fell beyond the expected decrease of the aforementioned misdemeanors (Miller, 2001). On the other hand, the causes of crime are still vague, as a complex of factors contribute. Most studies, however, empirically confirmed the â€Å"broken window† idea. For instance, Skogan conducted document analysis and scrutinized the earlier surveys in more than 40 localities. â€Å"He found that measures of social and physical decay correlated with certain kinds of serious crimes† (Miller, 2001, p. 28). On the other hand, new obstacles to policing emerged. As Kelling notes (1999), proactive approach to policing (prevention of crimes through putting the â€Å"broken window† concept into practice) is nowadays viewed by public as â€Å"soft policing†. On the other hand , â€Å"Community policing is inherently proactive: scan for problems; diagnose them; try to prevent them from occurring again; if they recur, try to limit the damage and restore the victim/family/community’s functioning† (Kelling, 1999, p. 10). This means, community policing often involves much more efforts than â€Å"crime fighting†, as in this case the commissioner or the police officer acts as an strategic analyst, supposed to have the ability to anticipate problems. Kelling’s approach to policing inherently includes regular interviews with community members, which means, police officers should keep in touch with the residents in order to identify the discuss the problems the community members are concerned about. In addition, the functioning of the whole law enforcement apparatus should be more transparent for community members, i. e. they should have an opportunity to learn the reasons for their neighbor’s arrest, for instance, as this measure is likely to act as a deterrent for others and a reminder about the policy’s care about public safety. On the other hand, a number of critics expressed their fear of the possible tendency for the expansion of the â€Å"soft policing† and the substantial elimination of reactive and radical measures. In this sense, Kelling alleges: â€Å" The fact that police add options to their repertoire of methods, try to limit damage and restore functioning does not mean that conventional assertive law enforcement is disallowed as a legitimate police tactic. For example, understanding the dynamics of New York City’s â€Å"squeegee men† –unwanted car window washers who intimidate drivers into giving them money – and talking to them did nothing to deter their behavior† (Kelling, 1999, p. 11). Nevertheless, as one can understand, civil law can be used by the police – as Kelling states, the new initiatives including such penalties like forfeiture, restitution and civil fines are placed upon those committing domestic violence, illegal weapons possession or disclose aggressive racist behavior. This means, a punishment should refer to the least possible intervention into the person’s life: for instance, if a criminal is not aggressive or dangerous and hasn’t committed grave crime, arrest is likely to appear a redundant measure. To sum up, the ‘broken window’ approach to policing refers not merely to the elimination of minor crimes, but also to the overall prevention of deviance and more extensive use of civil liberties in the issues like discretion. In general, Kerlling’s position is positivistic, as he views individuals as basically disciplined and law-abiding, but in order to increase public awareness in the importance of citizens’ own efforts in the sphere of public safety, it is important to show them that the police are sensitive and responsive even to the minor misconducts. Reference list Miller, D. (2001). Poking Holes in the Theory of ‘Broken Window’. Chronicle of Higher Education, 2: 27-34. Kelling, G. (1999). â€Å"Broken Windows† and Police Discretion. National Institute of Justice Research Report. Available online at: http://www. ncjrs. org/pdffiles1/nij/178259. pdf How to cite Broken window concept, Papers

Biology Simulator Assignment free essay sample

In vial one, a wild type hyper female Drosophila and wild type mellow male Drosophila were crossed respectively to determine the dominant behavioural phenotype. The first reciprocal cross was then carried out in vial two to define whether or not the behavioural phenotype is x-linked recessive. According to the results obtained from vial one, when the wild type hyper female and wild type mellow male was crossed, the resulting offspring’s phenotypes were all wild type hyper. This cross shows that the hyper behavioral phenotype can be considered dominant in comparison to mellow. In the reciprocal cross, the behavioural phenotypes were isolated from one another while the wing veins were kept constant (in this case both wild type). When the wild type mellow female Drosophila and wild type hyper male Drosophila were crossed, all female offspring obtained a similar phenotype to that of the male parental while all the male offspring had phenotypical combinations similar to that of the female parent. We will write a custom essay sample on Biology Simulator Assignment or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page This set of results shows that the mellow behavioral phenotype is a recessive x-linked gene carried by the female because the resulting male offspring showed the same characteristics to that of the female parent (received X – chromosome from female parent). On an additional note, there was a higher frequency of females in comparison to men; 121 and 105 respectively. In addition, the behavioral gene is sex -linked also because of the different resulting phenotypical ratio in comparison to the cross carried out in vial one. Another cross was carried out in vial three to determine the dominant wing vein phenotype. A wild type hyper female and veinless hyper male were crossed and as a result, all male offspring consisted phenotypical characteristics similar to that of the female parent while the female offspring had the same characteristics to that of the male parent. The results from this cross are somewhat similar to that of the reciprocal cross carried out in vial one. All male offspring had features exactly alike to that of the female parent, thus showing that wild type gene is x-linked recessive as all male offspring were wild type and hyper. It is also important to note that in this cross, a higher population of males existed than females (112 hyper wild type and 104 veinless hyper respectively). The second reciprocal cross was carried out in vial four directly after the above cross. This cross displayed a concise picture of which behavioral and wing vein phenotypes were dominant. Unlike the cross the done above, this time, a veinless hyper female and wild type hyper male were crossed and the resulting male and female offspring were all veinless hyper. Thus, proving veinless and hyper behaviour are the respective dominant phenotypes among the female and male Drosophila. Another cross was carried out to derive the first filial generation in which a veinless hyper female was crossed with a wild type mellow male and as a result, the offspring were all veinless hyper (a total of 214 offspring) which can be seen on the cross – record sheet under vial seven. A second filial generation was derived from a veinless hyper female and male Drosophila were crossed to distinguish a gene linkage relationship among the two phenotypes. Due to the genes being sex-linked, specifically x-linked recessive, the typical 9:3:3:1 ratio cannot be expected. However, a chi-squared test was carried out to determine how ‘’off’ our values were from the expected critical value of 7. 815 (obtained at a p-value of 0. 05) since such a ratio was not expected. A chi value of 31. 1 was achieved which is greater than the critical value. Thus, the null hypothesis is rejected because the genes are linked which means that they are located very closely together on corresponding chromosomes. However, hypothetically, if a 9:3:3:1 ratio had been expected and if the chi value had been less than the critical value, than the null hypothesis would have been accepted as this indicates that the genes are not linked and are independently assorted (less cross overs /variation).