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| 1 | +package scala |
| 2 | + |
| 3 | +package object quoted { |
| 4 | + |
| 5 | + /** Evaluate the contents of this expression and return the result. |
| 6 | + * It provides a new QuoteContext that is only valid within the scope the argument. |
| 7 | + * |
| 8 | + * Usage: |
| 9 | + * ``` |
| 10 | + * val e: T = run { // (given qctx: QuoteContext) => |
| 11 | + * expr |
| 12 | + * } |
| 13 | + * ``` |
| 14 | + * where `expr: Expr[T]` |
| 15 | + * |
| 16 | + * This method should not be called in a context where there is already has a `QuoteContext` |
| 17 | + * such as within a `run` or a `withQuoteContext`. |
| 18 | + */ |
| 19 | + def run[T](expr: given QuoteContext => Expr[T]) given (toolbox: Toolbox): T = toolbox.run(expr given _) |
| 20 | + |
| 21 | + /** Provide a new quote context within the scope of the argument that is only valid within the scope the argument. |
| 22 | + * Return the result of the argument. |
| 23 | + * |
| 24 | + * Usage: |
| 25 | + * ``` |
| 26 | + * val e: T = withQuoteContext { // (given qctx: QuoteContext) => |
| 27 | + * thunk |
| 28 | + * } |
| 29 | + * ``` |
| 30 | + * where `thunk: T` |
| 31 | + * |
| 32 | + * This method should not be called in a context where there is already has a `QuoteContext` |
| 33 | + * such as within a `run` or a `withQuoteContext`. |
| 34 | + */ |
| 35 | + def withQuoteContext[T](thunk: given QuoteContext => T) given (toolbox: Toolbox): T = { |
| 36 | + var result: T = NoResult.asInstanceOf[T] |
| 37 | + def dummyRun given QuoteContext: Expr[Unit] = { |
| 38 | + result = thunk |
| 39 | + Expr.unitExpr |
| 40 | + } |
| 41 | + toolbox.run(dummyRun given _) |
| 42 | + assert(result != NoResult) // toolbox.run should have thrown an exception |
| 43 | + result |
| 44 | + } |
| 45 | + |
| 46 | + private object NoResult |
| 47 | + |
| 48 | + object autolift { |
| 49 | + given autoToExpr[T] as Conversion[T, Expr[T]] given Liftable[T], QuoteContext = _.toExpr |
| 50 | + } |
| 51 | + |
| 52 | + implicit object ExprOps { |
| 53 | + def (x: T) toExpr[T: Liftable] given QuoteContext: Expr[T] = the[Liftable[T]].toExpr(x) |
| 54 | + |
| 55 | + /** Lifts this sequence of expressions into an expression of a sequence |
| 56 | + * |
| 57 | + * Transforms a sequence of expression |
| 58 | + * `Seq(e1, e2, ...)` where `ei: Expr[T]` |
| 59 | + * to an expression equivalent to |
| 60 | + * `'{ Seq($e1, $e2, ...) }` typed as an `Expr[Seq[T]]` |
| 61 | + * |
| 62 | + * Usage: |
| 63 | + * ```scala |
| 64 | + * '{ List(${List(1, 2, 3).toExprOfSeq}: _*) } // equvalent to '{ List(1, 2, 3) } |
| 65 | + * ``` |
| 66 | + */ |
| 67 | + def (seq: Seq[Expr[T]]) toExprOfSeq[T] given (tp: Type[T], qctx: QuoteContext): Expr[Seq[T]] = { |
| 68 | + import qctx.tasty._ |
| 69 | + Repeated(seq.map(_.unseal).toList, tp.unseal).seal.asInstanceOf[Expr[Seq[T]]] |
| 70 | + } |
| 71 | + |
| 72 | + /** Lifts this list of expressions into an expression of a list |
| 73 | + * |
| 74 | + * Transforms a list of expression |
| 75 | + * `List(e1, e2, ...)` where `ei: Expr[T]` |
| 76 | + * to an expression equivalent to |
| 77 | + * `'{ List($e1, $e2, ...) }` typed as an `Expr[List[T]]` |
| 78 | + */ |
| 79 | + def (list: List[Expr[T]]) toExprOfList[T] given Type[T], QuoteContext: Expr[List[T]] = |
| 80 | + throw new Exception("running on non bootstrapped library") |
| 81 | + |
| 82 | + /** Lifts this sequence of expressions into an expression of a tuple |
| 83 | + * |
| 84 | + * Transforms a sequence of expression |
| 85 | + * `Seq(e1, e2, ...)` where `ei: Expr[_]` |
| 86 | + * to an expression equivalent to |
| 87 | + * `'{ ($e1, $e2, ...) }` typed as an `Expr[Tuple]` |
| 88 | + */ |
| 89 | + def (seq: Seq[Expr[_]]) toExprOfTuple given QuoteContext: Expr[Tuple] = |
| 90 | + throw new Exception("running on non bootstrapped library") |
| 91 | + |
| 92 | + } |
| 93 | + |
| 94 | +} |
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