pSepBy

fun <I : Any, O, S, U : Any> pSepBy(item: Parser<I, O, U>, separator: Parser<I, S, U>): Parser<I, List<O>, U>

Returns a Parser that parses zero or more occurrences of item separated by separator, collecting the item values (not the separators) into a List.

The grammar matched is (item (separator item)*)?. The trailing separator, if present, is not consumed. Always succeeds; returns an empty list when item fails on the first attempt.

Behaviour

Condition	Result
item fails on the first attempt	Success with an empty list; index unchanged
item succeeds N times (N ≥ 1)	Success with N values; index advanced past all items and separators

Type parameters

I — the shared token type consumed by both parsers.
O — the output type of item; each value is collected.
S — the output type of separator; discarded.
U — the user context type threaded through unchanged.

Example

val digit = pSatisfy<Char, Unit> { it.isDigit() }
val comma = pSatisfy<Char, Unit> { it == ',' }
val parser = pSepBy(digit, comma)

val input = ParserInput.of("1,2,3".toList(), Unit)
val result = parser(input)  // Success(['1','2','3'], nextIndex=5, ...)

val empty = ParserInput.of("abc".toList(), Unit)
val result2 = parser(empty)  // Success([], nextIndex=0, ...)

Return

a Parser that always succeeds with a (possibly empty) list of item values.

Parameters

item

the parser for each item.

separator

the parser for the delimiter between items; its value is discarded.