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Regular expressions for JavaScript

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Regular expressions for JavaScript

  1. 1. John Blake University of Aizu Regular expressions for JavaScript /bbetweenW+(?:w+W+){1,2}?tob/gi; Pattern Modifier
  2. 2. Overview 02 Introduction • Probabilistic parsing • Rule-based pattern matching • Regular expressions Pedagogic examples • Error detection / proofreading • Annotating • Pronunciation
  3. 3. Probabilistic parsing 03 • Dynamic algorithms • Machine learning • Training sets (e.g. Stanford POS parser) Extremely powerful, but requires significant knowledge of computational linguistics and huge time investment so…
  4. 4. Rule-based pattern matching 04 1. There is a man on your left. T / F If true, a man is on your left. Stop. If false, proceed to 2. 2. There is a woman on your left. T / F If true, there is a woman on your left. Stop. If false, there is nobody on your left. Stop. True/false statements
  5. 5. Rule-based pattern matching 05 Decision-tree algorithm There is a man on your left. There is a woman on your left. No.Yes. STOP Yes. STOP No. There is nobody on your left. STOP Assumptions: 1. Only adults are present 2. There is no third gender
  6. 6. Regular expressions (Regex) 06 There is a man. /bmanb/; There is a woman. /bwomanb/; The discrete words “man” and “woman” will be identified, generating a “true” result. Literal characters Special characters (meta & class) (preceded by backslash ) b as in boy b boundary (of word) s as in sun s space I as in left I case insensitive (finds upper & lower case) g as in green g greedy (finds all)
  7. 7. Regular expressions (Regex) 07 1. /help/ 2. /bhelp/ – escape b – boundary 3. /bhelpb/ 4. /bHelpb/ 5. /bhelpb/i i – case insensitive 6. /bhelpb/g g – global (greedy) 7. /bhelpb/gi 8. /bgreyb/gi 9. /bgr(a|e)yb/gi | - pipe (Boolean “or”) 10. /bgr[ae]yb/gi
  8. 8. Regular expressions (Regex) 08 e.g. /bmaybeb/gi; – escape (from normal characters) i – case insensitive b – boundary g – greedy (global) 1. I think that maybe he can understand. T/F 2. He may be able to understand T/F 3. Maybe, he can understand. T/F 4. Maybelline is a company name. T/F 5. Maybe, he said maybe. T/F
  9. 9. 09 Proofreading Target • One of the + singular noun Regex • /bone of theb/gi; Execute • Check that the phrase one of the is followed by a plural noun Eg. 1
  10. 10. 10 Difficult-to-read tags Introduction Purpose Method Results Discussion <segment features='problem;introduction;rhetorical_moves' state='active'>We address the problem of model-based object recognition.</segment> <segment features='purpose;rhetorical_moves' state='active'>Our aim is to localize and recognize road vehicles from monocular images or videos in calibrated traffic scenes.</segment> <segment features='method;rhetorical_moves' state='active'>A 3-D deformable vehicle model with 12 shape parameters is set up as prior information, and its pose is determined by three parameters, which are its position on the ground plane and its orientation about the vertical axis under ground-plane constraints.</segment> <segment features='purpose;rhetorical_moves' state='active'>An efficient local gradient-based method is proposed to evaluate the fitness between the projection of the vehicle model and image data, which is combined into a novel evolutionary computing framework to estimate the 12 shape parameters and three pose parameters by iterative evolution.</segment> <segment features='background;introduction;rhetorical_moves' state='active'>The recovery of pose parameters achieves vehicle localization, whereas the shape parameters are used for vehicle recognition.</segment> <segment features='method;rhetorical_moves' state='active'>Numerous experiments are Eg. 2
  11. 11. 11 Difficult-to-read tags Introduction Purpose Method Results Discussion <segment features='problem;introduction;rhetorical_moves' state='active'>We address the problem of model-based object recognition.</segment> <segment features='purpose;rhetorical_moves' state='active'>Our aim is to localize and recognize road vehicles from monocular images or videos in calibrated traffic scenes.</segment> <segment features='method;rhetorical_moves' state='active'>A 3-D deformable vehicle model with 12 shape parameters is set up as prior information, and its pose is determined by three parameters, which are its position on the ground plane and its orientation about the vertical axis under ground-plane constraints.</segment> <segment features='purpose;rhetorical_moves' state='active'>An efficient local gradient-based method is proposed to evaluate the fitness between the projection of the vehicle model and image data, which is combined into a novel evolutionary computing framework to estimate the 12 shape parameters and three pose parameters by iterative evolution.</segment> <segment features='background;introduction;rhetorical_moves' state='active'>The recovery of pose parameters achieves vehicle localization, whereas the shape parameters are used for vehicle recognition.</segment> <segment features='method;rhetorical_moves' state='active'>Numerous experiments are Eg. 2
  12. 12. 12 Easy-to-read tags Introduction Purpose Method Results Discussion Eg. 2
  13. 13. 13 Regular “-ed” False positives: • learned /d/ /id/ Pron Preceeding sound Potential regex /id/ d, t /[dt]edb/gi; /t/ voiceless consonants /[sf]edb/gi; /d/ voiced consonants /[zv]edb/gi; /d/ Vowel /(ow|i|ay)edb/gi; Pronunciation of “ed” is dictated by the sound of the preceeding letter(s). | – Boolean “or” so x|y means either x or y d|ted means d or ted but by adding brackets (d|t)ed means ded or ted Eg. 3
  14. 14. 14 Pronunciation of “th-” Pron Feature Potential regex /𝜽/ Voiceless initial th /bth/gi; - This is the default. /t/ th pronounced as t /bthomas|thames|thyme/gi; - This deals with special cases /𝜹/ Voiced initial th /btha(n|t) b/gi; /bthe(m|y) b/gi; /bth(eir|ere|ese|) b/gi; /bthisb/gi; /btho(se|ugh) b/gi; /bthusb/gi; - These covert /𝜽/ to /𝜹/ Pronunciation of “th” can be predicted by the rule that for function words the initial th is pronounced as a voiced sound. These regex used in sequence can annotate for many “th” sounds. Eg. 4

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