96adf04a62
Makes it possible to `extend` another structure through an abbreviation. Also inserts a `withSynthesize` checkpoint for parents. Closes #5417
26 lines
474 B
Text
26 lines
474 B
Text
/-!
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# Reduce parents in structure `extends` clause
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-/
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structure A
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abbrev B := A
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/-!
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This already worked before the fix. Structure instances unfold the expected type.
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-/
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/-- info: { } : A -/
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#guard_msgs in #check { : B}
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/-!
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This is now allowed. The parent `B` is unfolded.
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-/
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structure C extends B
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/-- info: { } : C -/
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#guard_msgs in #check { : C}
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/-!
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Note that the parent projection is for `A`, not `B`.
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-/
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/-- info: C.toA (self : C) : A -/
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#guard_msgs in #check C.toA
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