konnosBackwardIterator.ts212 lines · main
| 1 | // Porting from |
| 2 | // https://github.com/Borvik/vscode-postgres/blob/master/src/common/backwordIterator.ts |
| 3 | |
| 4 | const _NL = '\n'.charCodeAt(0) |
| 5 | const _TAB = '\t'.charCodeAt(0) |
| 6 | const _WSB = ' '.charCodeAt(0) |
| 7 | const _LBracket = '['.charCodeAt(0) |
| 8 | const _RBracket = ']'.charCodeAt(0) |
| 9 | const _LCurly = '{'.charCodeAt(0) |
| 10 | const _RCurly = '}'.charCodeAt(0) |
| 11 | const _LParent = '('.charCodeAt(0) |
| 12 | const _RParent = ')'.charCodeAt(0) |
| 13 | const _Comma = ','.charCodeAt(0) |
| 14 | const _Period = '.'.charCodeAt(0) |
| 15 | const _Quote = "'".charCodeAt(0) |
| 16 | const _DQuote = '"'.charCodeAt(0) |
| 17 | const _USC = '_'.charCodeAt(0) |
| 18 | // _a will give undefined... so rename to _aCode |
| 19 | const _aCode = 'a'.charCodeAt(0) |
| 20 | const _z = 'z'.charCodeAt(0) |
| 21 | const _A = 'A'.charCodeAt(0) |
| 22 | const _Z = 'Z'.charCodeAt(0) |
| 23 | const _0 = '0'.charCodeAt(0) |
| 24 | const _9 = '9'.charCodeAt(0) |
| 25 | |
| 26 | const BOF = 0 |
| 27 | |
| 28 | class BackwardIterator { |
| 29 | _line |
| 30 | _text |
| 31 | _lines |
| 32 | |
| 33 | model |
| 34 | offset |
| 35 | lineNumber |
| 36 | |
| 37 | constructor(model: any, offset: number, lineNumber: number) { |
| 38 | this.model = model |
| 39 | this.offset = offset |
| 40 | this.lineNumber = lineNumber |
| 41 | |
| 42 | this._text = model.getValue() |
| 43 | this._lines = this._text.split(/\r?\n/g) |
| 44 | this._line = this._lines[lineNumber] |
| 45 | } |
| 46 | |
| 47 | hasNext() { |
| 48 | return this.lineNumber >= 0 || this.offset >= 0 |
| 49 | } |
| 50 | |
| 51 | isFowardDQuote() { |
| 52 | if (!this.hasForward()) return false |
| 53 | return this.peekForward() === _DQuote |
| 54 | } |
| 55 | |
| 56 | isNextDQuote() { |
| 57 | if (!this.hasNext()) return false |
| 58 | return this.peekNext() === _DQuote |
| 59 | } |
| 60 | |
| 61 | isNextPeriod() { |
| 62 | if (!this.hasNext()) return false |
| 63 | return this.peekNext() === _Period |
| 64 | } |
| 65 | |
| 66 | peekNext() { |
| 67 | if (this.offset < 0) { |
| 68 | if (this.lineNumber > 0) { |
| 69 | return _NL |
| 70 | } |
| 71 | return BOF |
| 72 | } |
| 73 | return this._line.charCodeAt(this.offset) |
| 74 | } |
| 75 | |
| 76 | hasForward() { |
| 77 | return this.lineNumber < this._lines.length || this.offset < this._line.length |
| 78 | } |
| 79 | |
| 80 | peekForward() { |
| 81 | if (this.offset === this._line.length) { |
| 82 | if (this.lineNumber === this._lines.length) return BOF |
| 83 | return _NL |
| 84 | } |
| 85 | return this._line.charCodeAt(this.offset + 1) |
| 86 | } |
| 87 | |
| 88 | next() { |
| 89 | if (this.offset < 0) { |
| 90 | if (this.lineNumber > 0) { |
| 91 | this.lineNumber-- |
| 92 | this._line = this._lines[this.lineNumber] |
| 93 | this.offset = this._line.length - 1 |
| 94 | return _NL |
| 95 | } |
| 96 | this.lineNumber = -1 |
| 97 | return BOF |
| 98 | } |
| 99 | let ch = this._line.charCodeAt(this.offset) |
| 100 | this.offset-- |
| 101 | return ch |
| 102 | } |
| 103 | |
| 104 | readArguments() { |
| 105 | let parentNesting = 0 |
| 106 | let bracketNesting = 0 |
| 107 | let curlyNesting = 0 |
| 108 | let paramCount = 0 |
| 109 | while (this.hasNext()) { |
| 110 | let ch = this.next() |
| 111 | switch (ch) { |
| 112 | case _LParent: |
| 113 | parentNesting-- |
| 114 | if (parentNesting < 0) { |
| 115 | return paramCount |
| 116 | } |
| 117 | break |
| 118 | case _RParent: |
| 119 | parentNesting++ |
| 120 | break |
| 121 | case _LCurly: |
| 122 | curlyNesting-- |
| 123 | break |
| 124 | case _RCurly: |
| 125 | curlyNesting++ |
| 126 | break |
| 127 | case _LBracket: |
| 128 | bracketNesting-- |
| 129 | break |
| 130 | case _RBracket: |
| 131 | bracketNesting++ |
| 132 | break |
| 133 | case _DQuote: |
| 134 | case _Quote: |
| 135 | while (this.hasNext() && ch !== this.next()) { |
| 136 | // find the closing quote or double quote |
| 137 | } |
| 138 | break |
| 139 | case _Comma: |
| 140 | if (!parentNesting && !bracketNesting && !curlyNesting) { |
| 141 | paramCount++ |
| 142 | } |
| 143 | break |
| 144 | } |
| 145 | } |
| 146 | return -1 |
| 147 | } |
| 148 | |
| 149 | readIdent() { |
| 150 | let identStarted = false |
| 151 | let isQuotedIdentifier = false |
| 152 | let ident = '' |
| 153 | |
| 154 | while (this.hasNext()) { |
| 155 | // Peek first and check if is part of identifier |
| 156 | let ch = this.peekNext() |
| 157 | if (identStarted && !isQuotedIdentifier && !this._isIdentPart(ch)) break |
| 158 | |
| 159 | ch = this.next() |
| 160 | |
| 161 | if (!identStarted && isQuotedIdentifier && ch === _DQuote) { |
| 162 | identStarted = true |
| 163 | continue |
| 164 | } |
| 165 | if (!identStarted && (ch === _WSB || ch === _TAB || ch == _NL)) continue |
| 166 | |
| 167 | if (!identStarted && (ch === _DQuote || this._isIdentPart(ch))) { |
| 168 | identStarted = true |
| 169 | isQuotedIdentifier = ch === _DQuote |
| 170 | ident = String.fromCharCode(ch) + ident |
| 171 | } else if (identStarted) { |
| 172 | if (isQuotedIdentifier) { |
| 173 | if (ch === BOF) break |
| 174 | ident = String.fromCharCode(ch) + ident |
| 175 | if (ch === _DQuote) break |
| 176 | } else { |
| 177 | ident = String.fromCharCode(ch) + ident |
| 178 | } |
| 179 | } |
| 180 | } |
| 181 | return ident |
| 182 | } |
| 183 | |
| 184 | readIdents(maxlvl: number) { |
| 185 | let idents = [] |
| 186 | while (maxlvl > 0) { |
| 187 | maxlvl-- |
| 188 | let ident = this.readIdent() |
| 189 | if (!ident) { |
| 190 | break |
| 191 | } |
| 192 | |
| 193 | idents.push(ident) |
| 194 | |
| 195 | if (!this.isNextPeriod()) { |
| 196 | break |
| 197 | } |
| 198 | } |
| 199 | return idents.reverse() |
| 200 | } |
| 201 | |
| 202 | _isIdentPart(ch: number) { |
| 203 | return ( |
| 204 | ch === _USC || // _ |
| 205 | (ch >= _aCode && ch <= _z) || // a-z |
| 206 | (ch >= _A && ch <= _Z) || // A-Z |
| 207 | (ch >= _0 && ch <= _9) |
| 208 | ) // 0-9 |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | export default BackwardIterator |