const P = require('parsimmon')
P.regexp(/[a-z]+/)
.parse('hello')
//=> { status: true, value: ['hello'] }
Atoms
P.regexp(/[a-z]+/)
P.string('hello')
P.oneOf('abc') // like P.regexp(/[abc]/)
P.whitespace
P.optWhitespace
P.eof
Combinators
P.seq(a, b, c) // sequence of these
P.alt(a, b) // any of these
P.sepBy(a, P.string(',')) // sequence of `a`, separated by ','
P.sepBy1(a, P.string(',')) // same, at least once
a.or(b) // like P.alt(a, b)
a.skip(b) // parses `b` but discards it
a.many()
a.times(3)
a.times(1, 4) // 1 <= x <= 4
a.atMost(10)
a.atLeast(10)
P.seq(P.number, P.oneOf('+-*/'), P.number)
.map(([left, oper, right]) => ({ oper, left, right }))
Reference