Function provide

src/runtime/builder.ts:583–591

(variable, scan)

  let blockLevel = {};

  let provide = (variable, scan) => {
    if(join.isVariable(variable)) {
      let info = variableInfo[variable.id]
      if(!info) {
        info = variableInfo[variable.id] = {providers: []};
      }
      info.providers.push(scan);
    }
  }

  let maybeLevelVariable = (scan, level, variable) => {
    if(join.isVariable(variable)) {