@ARTICLE{Anquetil22-IST-MagicLiterals,
   AUTHOR       = {Nicolas Anquetil and Julien Delplanque and 
      St�phane Ducasse and Oleksandr Zaitsev and Christopher P. Fuhrman and 
      Yann-Ga�l Gu�h�neuc},
   JOURNAL      = {Information and Software Technology (IST)},
   TITLE        = {What Do Developers Consider Magic Literals? A Smalltalk 
      Perspective},
   YEAR         = {2022},
   MONTH        = {September},
   NOTE         = {14 pages.},
   OPTNUMBER    = {},
   PAGES        = {106942},
   VOLUME       = {149},
   EDITOR       = {Claes Wohlin},
   KEYWORDS     = {Topic: <b>Program comprehension</b>, Venue: <b>IST</b>},
   PUBLISHER    = {Elsevier},
   URL          = {http://www.ptidej.net/publications/documents/IST22.doc.pdf},
   ABSTRACT     = {Context: Literals are constant values (numbers, strings, 
      etc.) used in the source code. Magic literals are such values used 
      without an explicit explanation of their meaning. Such undocumented 
      values may hinder sourcecode comprehension, negatively impacting 
      maintenance. Relatively little literature can be found on the subject 
      beyond the usual (and very old) recommendation of avoiding literals 
      and preferring named constants. Yet, magic literals are still 
      routinely found in source code. Objective: We studied literal values 
      in source code to understand when they should be considered magic or 
      not (i.e., acceptable). Methods: First, we perform a qualitative 
      study of magic literals, to establish why and under which conditions 
      they are considered harmful. We formalize hypotheses about the 
      reasoning behind how literals are considered magic. Second, we 
      perform a quantitative study on seven real systems ranging from small 
      (a few classes) to large (thousands of classes). We report the 
      literals' types (number, string, Boolean,. . .), their grammatical 
      function (e.g., argument in a call, operand in an expression, value 
      assigned,. . .), or the purpose of the code in which they appear 
      (test methods, regular code). Third, we report on another study 
      involving 26 programmers who analyzed about 24,000 literals, to 
      understand which ones they consider magic. Finally, we evaluate the 
      hypotheses defining specific conditions under which literals are 
      acceptable. Results: We show that (1) literals still exist and are 
      relatively frequent (found in close to 50\NOof the methods 
      considered); (2) they are more frequent in test methods (in 80\NOof 
      test methods); (3) to a large extent, they were considered acceptable 
      (only 25\NOconsidered magic); and (4) the hypotheses concerning 
      acceptable literals are valid to various degrees. Conclusion: We thus 
      pave the way to future research on magic literals, for example, with 
      tools that could help developers deciding if a literal is acceptable.}
}

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A Smalltalk Perspective","year":"2022","month":"September","note":"14 pages.","optnumber":"","pages":"106942","volume":"149","editor":[{"firstnames":["Claes"],"propositions":[],"lastnames":["Wohlin"],"suffixes":[]}],"keywords":"Topic: <b>Program comprehension</b>, Venue: <b>IST</b>","publisher":"Elsevier","url":"http://www.ptidej.net/publications/documents/IST22.doc.pdf","abstract":"Context: Literals are constant values (numbers, strings, etc.) used in the source code. Magic literals are such values used without an explicit explanation of their meaning. Such undocumented values may hinder sourcecode comprehension, negatively impacting maintenance. Relatively little literature can be found on the subject beyond the usual (and very old) recommendation of avoiding literals and preferring named constants. Yet, magic literals are still routinely found in source code. Objective: We studied literal values in source code to understand when they should be considered magic or not (i.e., acceptable). Methods: First, we perform a qualitative study of magic literals, to establish why and under which conditions they are considered harmful. We formalize hypotheses about the reasoning behind how literals are considered magic. Second, we perform a quantitative study on seven real systems ranging from small (a few classes) to large (thousands of classes). We report the literals' types (number, string, Boolean,. . .), their grammatical function (e.g., argument in a call, operand in an expression, value assigned,. . .), or the purpose of the code in which they appear (test methods, regular code). Third, we report on another study involving 26 programmers who analyzed about 24,000 literals, to understand which ones they consider magic. Finally, we evaluate the hypotheses defining specific conditions under which literals are acceptable. Results: We show that (1) literals still exist and are relatively frequent (found in close to 50\\NOof the methods considered); (2) they are more frequent in test methods (in 80\\NOof test methods); (3) to a large extent, they were considered acceptable (only 25\\NOconsidered magic); and (4) the hypotheses concerning acceptable literals are valid to various degrees. Conclusion: We thus pave the way to future research on magic literals, for example, with tools that could help developers deciding if a literal is acceptable.","bibtex":"@ARTICLE{Anquetil22-IST-MagicLiterals,\r\n AUTHOR = {Nicolas Anquetil and Julien Delplanque and \r\n St�phane Ducasse and Oleksandr Zaitsev and Christopher P. Fuhrman and \r\n Yann-Ga�l Gu�h�neuc},\r\n JOURNAL = {Information and Software Technology (IST)},\r\n TITLE = {What Do Developers Consider Magic Literals? A Smalltalk \r\n Perspective},\r\n YEAR = {2022},\r\n MONTH = {September},\r\n NOTE = {14 pages.},\r\n OPTNUMBER = {},\r\n PAGES = {106942},\r\n VOLUME = {149},\r\n EDITOR = {Claes Wohlin},\r\n KEYWORDS = {Topic: <b>Program comprehension</b>, Venue: <b>IST</b>},\r\n PUBLISHER = {Elsevier},\r\n URL = {http://www.ptidej.net/publications/documents/IST22.doc.pdf},\r\n ABSTRACT = {Context: Literals are constant values (numbers, strings, \r\n etc.) used in the source code. Magic literals are such values used \r\n without an explicit explanation of their meaning. Such undocumented \r\n values may hinder sourcecode comprehension, negatively impacting \r\n maintenance. Relatively little literature can be found on the subject \r\n beyond the usual (and very old) recommendation of avoiding literals \r\n and preferring named constants. Yet, magic literals are still \r\n routinely found in source code. Objective: We studied literal values \r\n in source code to understand when they should be considered magic or \r\n not (i.e., acceptable). Methods: First, we perform a qualitative \r\n study of magic literals, to establish why and under which conditions \r\n they are considered harmful. We formalize hypotheses about the \r\n reasoning behind how literals are considered magic. Second, we \r\n perform a quantitative study on seven real systems ranging from small \r\n (a few classes) to large (thousands of classes). We report the \r\n literals' types (number, string, Boolean,. . .), their grammatical \r\n function (e.g., argument in a call, operand in an expression, value \r\n assigned,. . .), or the purpose of the code in which they appear \r\n (test methods, regular code). Third, we report on another study \r\n involving 26 programmers who analyzed about 24,000 literals, to \r\n understand which ones they consider magic. Finally, we evaluate the \r\n hypotheses defining specific conditions under which literals are \r\n acceptable. Results: We show that (1) literals still exist and are \r\n relatively frequent (found in close to 50\\NOof the methods \r\n considered); (2) they are more frequent in test methods (in 80\\NOof \r\n test methods); (3) to a large extent, they were considered acceptable \r\n (only 25\\NOconsidered magic); and (4) the hypotheses concerning \r\n acceptable literals are valid to various degrees. Conclusion: We thus \r\n pave the way to future research on magic literals, for example, with \r\n tools that could help developers deciding if a literal is acceptable.}\r\n}\r\n\r\n","author_short":["Anquetil, N.","Delplanque, J.","Ducasse, S.","Zaitsev, O.","Fuhrman, C. P.","Gu�h�neuc, Y."],"editor_short":["Wohlin, C."],"key":"Anquetil22-IST-MagicLiterals","id":"Anquetil22-IST-MagicLiterals","bibbaseid":"anquetil-delplanque-ducasse-zaitsev-fuhrman-guhneuc-whatdodevelopersconsidermagicliteralsasmalltalkperspective-2022","role":"author","urls":{"Paper":"http://www.ptidej.net/publications/documents/IST22.doc.pdf"},"keyword":["Topic: <b>Program comprehension</b>","Venue: <b>IST</b>"],"metadata":{"authorlinks":{}}},"bibtype":"article","biburl":"http://www.yann-gael.gueheneuc.net/Work/Publications/Biblio/complete-bibliography.bib","dataSources":["8vn5MSGYWB4fAx9Z4"],"keywords":["topic: <b>program comprehension</b>","venue: <b>ist</b>"],"search_terms":["developers","consider","magic","literals","smalltalk","perspective","anquetil","delplanque","ducasse","zaitsev","fuhrman","gu�h�neuc"],"title":"What Do Developers Consider Magic Literals? A Smalltalk Perspective","year":2022}