cloki/plugins/base/macros/index.js

LogQL API with Clickhouse Backend

const { PluginTypeLoaderBase } = require('plugnplay')
const ruleNames = new Set()
module.exports = class extends PluginTypeLoaderBase {
  exportSync (opts) {
    return {
      props: ['bnf', 'stringify', '_main_rule_name'],
      validate: (exports) => {
        for (const f of ['bnf', 'stringify']) {
          if (!exports[f]) {
            throw new Error(`missing field ${f}`)
          }
        }
        const rules = exports.bnf.split('\n')
        if (rules[0] === '') {
          throw new Error('First line should be the main rule')
        }
        for (const rule of rules) {
          if (rule === '') {
            continue
          }
          const name = rule.match(/^(\w+)\s*::=/)
          if (!name) {
            throw new Error(`invalid bnf rule: ${rule}`)
          }
          if (name[1].substr(0, 6) !== 'MACRO_') {
            throw new Error(`${name[1]} token name should start with "MACRO_"`)
          }
          if (ruleNames.has(name[1])) {
            throw new Error(`${name[1]} token already registered`)
          }
          ruleNames.add(name[1])
        }
        exports._main_rule_name = rules[0].match(/^(\w+)\s*::=/)[1]
      }
    }
  }
}