c5bea23a54
This PR adds a `value_of% ident` term that elaborates to the value of the local or global constant `ident`. This is useful for creating definition hypotheses: ```lean let x := ... complicated expression ... have hx : x = value_of% x := rfl ```
68 lines
1.2 KiB
Text
68 lines
1.2 KiB
Text
/-!
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# Testing the `value_of%` term elaborator
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-/
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/-!
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Basic case of success for local definitions.
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-/
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/--
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trace: x : Nat := 1 + 1
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hx : x = 1 + 1
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⊢ True
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-/
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#guard_msgs in
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example : True := by
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let x := 1 + 1
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have hx : x = value_of% x := rfl
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trace_state
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trivial
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/-!
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Basic case of success for global constants.
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Note that it evaluates to a lambda with an implicit parameter.
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-/
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/--
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trace: hx : @id = fun {α} a => a
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⊢ True
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-/
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#guard_msgs in
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example : True := by
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have hx : @id.{1} = value_of% id := rfl
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trace_state
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trivial
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/-!
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Referring to a global constant with no value.
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-/
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/--
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error: Constant has no value.
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---
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error: unsolved goals
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⊢ True
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-/
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#guard_msgs in
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example : True := by
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let a := value_of% True
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/-!
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Referring to a non-existent identifier, error.
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-/
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/--
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error: unknown constant '_TESTS_LEAN_RUN_VALUETERM_not_used_in_Lean'
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---
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error: unsolved goals
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⊢ True
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-/
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#guard_msgs in
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example : True := by
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let a := value_of% _TESTS_LEAN_RUN_VALUETERM_not_used_in_Lean
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/-!
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Referring to a cdecl, error since no value.
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-/
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/-- error: Local declaration has no value. -/
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#guard_msgs in
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example : True := by
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have x := 1 + 1
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have hx : x = value_of% x := rfl
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