acerix /
cnum
| Conditions | 16 |
| Total Lines | 89 |
| Code Lines | 65 |
| Lines | 0 |
| Ratio | 0 % |
| Tests | 55 |
| CRAP Score | 16 |
| Changes | 0 | ||
Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.
For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.
Commonly applied refactorings include:
If many parameters/temporary variables are present:
Complex classes like Lexer.lex often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
| 1 | 3 | import Token, { TokenType } from './Token' |
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| 29 | |||
| 30 | /** |
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| 31 | * Yields tokens as they are lexed. |
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| 32 | * |
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| 33 | */ |
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| 34 | *lex(): Generator<Token> { |
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| 35 | 14 | let onSpace = false |
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| 36 | 14 | let onInteger = false |
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| 37 | 14 | let onWord = false |
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| 38 | 14 | let onOperator = false |
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| 39 | 14 | let buffer = '' |
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| 40 | |||
| 41 | // for each character |
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| 42 | 14 | for (let i=0; i<this.s.length; i++) { |
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| 43 | 59 | const char = this.s[i] |
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| 44 | |||
| 45 | // if a space, combine with subsequent spaces into a separator |
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| 46 | 59 | if (/^\s$/.exec(char)) { |
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| 47 | 12 | if (onInteger) { |
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| 48 | 4 | yield new Token(TokenType.literal, buffer) |
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| 49 | 4 | onInteger = false |
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| 50 | 4 | buffer = '' |
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| 51 | } |
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| 52 | 8 | else if (onWord) { |
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| 53 | 2 | yield new Token(TokenType.identifier, buffer) |
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| 54 | 2 | onWord = false |
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| 55 | 2 | buffer = '' |
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| 56 | } |
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| 57 | 12 | onSpace = true |
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| 58 | 12 | buffer += char |
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| 59 | 12 | continue |
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| 60 | } |
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| 61 | 47 | else if (onSpace) { |
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| 62 | 7 | yield new Token(TokenType.separator, '') |
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| 63 | 7 | onSpace = false |
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| 64 | 7 | buffer = '' |
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| 65 | } |
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| 66 | |||
| 67 | // if a digit, combine with subsequent digits into a literal |
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| 68 | 47 | if (/^\d$/.exec(char)) { |
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| 69 | 14 | if (!onWord) { |
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| 70 | 11 | onInteger = true |
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| 71 | } |
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| 72 | 14 | buffer += char |
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| 73 | 14 | continue |
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| 74 | } |
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| 75 | 33 | else if (onInteger) { |
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| 76 | 1 | yield new Token(TokenType.literal, buffer) |
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| 77 | 1 | onInteger = false |
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| 78 | 1 | buffer = '' |
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| 79 | } |
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| 80 | |||
| 81 | // if a letter, combine with subsequent letters/numbers into an identifier |
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| 82 | 33 | if (/^[a-z]$/.exec(char) || (onWord && /^\d$/.exec(char))) { |
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| 83 | 26 | onWord = true |
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| 84 | 26 | buffer += char |
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| 85 | 26 | continue |
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| 86 | } |
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| 87 | 7 | else if (onWord) { |
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| 88 | 1 | yield new Token(TokenType.identifier, buffer) |
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| 89 | 1 | onWord = false |
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| 90 | 1 | buffer = '' |
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| 91 | } |
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| 92 | |||
| 93 | // if another char, combine with subsequent char and match an operator |
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| 94 | 7 | buffer += char |
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| 95 | 7 | if (buffer in OPERATORS) { |
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| 96 | 3 | yield new Token(TokenType.operator, buffer) |
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| 97 | 3 | onOperator = false |
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| 98 | 3 | buffer = '' |
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| 99 | 3 | continue |
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| 100 | } |
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| 101 | 4 | if (onOperator) { |
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| 102 | 2 | throw `Invalid operator "${buffer}"` |
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| 103 | } |
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| 104 | 2 | onOperator = true |
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| 105 | |||
| 106 | } |
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| 107 | |||
| 108 | 12 | if (onSpace) { |
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| 109 | 3 | yield new Token(TokenType.separator, '') |
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| 110 | } |
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| 111 | |||
| 112 | 12 | if (onInteger) { |
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| 113 | 3 | yield new Token(TokenType.literal, buffer) |
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| 114 | } |
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| 115 | |||
| 116 | 12 | if (onWord) { |
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| 117 | 6 | yield new Token(TokenType.identifier, buffer) |
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| 118 | } |
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| 125 |
