Interests: meta-programming, datavis, parsers, dataflow
Published
Edited
Jan 9, 2020
parseList = {
const lookupWithDefault = (name, defaultParser) => {
const lookupName = (env) => {
if (!env) return defaultParser
if (env[name]) return env[name]
else {
if (env.parentEnv) return lookupName(env.parentEnv)
else return defaultParser
}
}
return lookupName
}
const deriveEnvironment = (env) => {
let newEnv = { parentEnv: env }
// If we're not on the outermost level, use square brackets as list
// delimiters instead.
if (env) {
newEnv.listOpener = p.string("[")
newEnv.listCloser = p.string("]")
}
return newEnv
}
const opener = p.from(lookupWithDefault("listOpener", p.string("(")))
const closer = p.from(lookupWithDefault("listCloser", p.string(")")))
let list
const listContent = p.from(() => p.times(list, 0, Infinity))
list = p.subEnv(
p.map(
p.seq(opener, listContent, closer),
([opener, content, closer]) => `list(${content.join(", ")})`),
deriveEnvironment)
return list
}
parseList("()")
p.times(parseList, 0, Infinity)("([[]][])()([])")
parseList("[]")
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.