b0b922bae4
Before, Lean would simply emit the message "tag not found". With this change, it also tells the user what they could have written that would be accepted.
45 lines
954 B
Text
45 lines
954 B
Text
/-!
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# Provide case alternatives in "nonexistent tag" message
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Test that the available case tags are suggested when a nonexistent
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tag is requested. -/
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/-!
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This example tests what happens when no cases are available. -/
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theorem noCases : Nat := by
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case nonexistent =>
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skip
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/-!
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This example tests what happens when just one case is available, but
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it wasn't picked. -/
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theorem oneCase : Nat := by
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cases ()
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case nonexistent =>
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skip
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/-!
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Check varying numbers of cases to make sure the pretty-print setup for
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the list is correct. -/
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theorem twoCases : Nat := by
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cases true
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case nonexistent =>
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skip
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theorem fourCases : Nat := by
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cases true <;> cases true
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case nonexistent =>
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skip
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theorem eightCases : Nat := by
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cases true <;> cases true <;> cases true
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case nonexistent =>
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skip
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theorem sixteenCases : Nat := by
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cases true <;> cases true <;> cases true <;> cases true
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case nonexistent =>
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skip
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