| 139 | } |
| 140 | |
| 141 | function parse(code, ctxIdentifier) { |
| 142 | const tokens = tokenize(code); |
| 143 | |
| 144 | let i = 0; |
| 145 | function parseExpression() { |
| 146 | let left = parseBinary(); |
| 147 | while (true) { |
| 148 | const token = tokens[i]; |
| 149 | if (token !== undefined) { |
| 150 | switch (token.type) { |
| 151 | case '||': |
| 152 | case '&&': { |
| 153 | i++; |
| 154 | const right = parseBinary(); |
| 155 | if (right === null) { |
| 156 | throw Error('Missing expression after ' + token.type); |
| 157 | } |
| 158 | left = t.logicalExpression(token.type, left, right); |
| 159 | continue; |
| 160 | } |
| 161 | } |
| 162 | } |
| 163 | break; |
| 164 | } |
| 165 | return left; |
| 166 | } |
| 167 | |
| 168 | function parseBinary() { |
| 169 | let left = parseUnary(); |
| 170 | while (true) { |
| 171 | const token = tokens[i]; |
| 172 | if (token !== undefined) { |
| 173 | switch (token.type) { |
| 174 | case '==': |
| 175 | case '!=': { |
| 176 | i++; |
| 177 | const right = parseUnary(); |
| 178 | if (right === null) { |
| 179 | throw Error('Missing expression after ' + token.type); |
| 180 | } |
| 181 | left = t.binaryExpression(token.type, left, right); |
| 182 | continue; |
| 183 | } |
| 184 | } |
| 185 | } |
| 186 | break; |
| 187 | } |
| 188 | return left; |
| 189 | } |
| 190 | |
| 191 | function parseUnary() { |
| 192 | const token = tokens[i]; |
| 193 | if (token !== undefined) { |
| 194 | if (token.type === '!') { |
| 195 | i++; |
| 196 | const argument = parseUnary(); |
| 197 | return t.unaryExpression('!', argument); |
| 198 | } |