Jinseong Jeon
38 lines
1.6 KiB
Kotlin
Vendored
38 lines
1.6 KiB
Kotlin
Vendored
//KT-10934 compiler throws UninferredParameterTypeConstructor in when block that covers all types
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class Parser<TInput, TValue>(val f: (TInput) -> Result<TInput, TValue>) {
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operator fun invoke(input: TInput): Result<TInput, TValue> = f(input)
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fun <TIntermediate, TValue2> mapJoin(
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selector: (TValue) -> Parser<TInput, TIntermediate>,
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projector: (TValue, TIntermediate) -> TValue2
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): Parser<TInput, TValue2> {
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return Parser({ input ->
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val res = this(input)
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when (res) {
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is Result.ParseError -> Result.ParseError(res.productionLabel, res.child, res.rest)
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is Result.Value -> {
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val v = res.value
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val res2 = selector(v)(res.rest)
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when (res2) {
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is Result.ParseError -> Result.ParseError(res2.productionLabel, res2.child, res2.rest)
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is Result.Value -> Result.Value(projector(v, res2.value), res2.rest)
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}
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}
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}
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})
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}
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}
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/** A parser can return one of two Results */
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sealed class Result<TInput, TValue> {
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class Value<TInput, TValue>(val value: TValue, val rest: TInput) : Result<TInput, TValue>() {}
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class ParseError<TInput, TValue>(val productionLabel: String,
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val child: ParseError<TInput, *>?,
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val rest: TInput) : Result<TInput, TValue>() {}
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}
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fun box() = "OK" |