40e8f4c5fb
This PR turns on the new `do` elaborator in Init, Lean, Std, Lake and the testsuite. --------- Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
28 lines
656 B
Text
28 lines
656 B
Text
import Lean
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set_option backward.do.legacy false
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open Lean Elab Meta
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def somethingBad : MetaM Nat := do
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IO.println "oh no"
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return 1
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/-- error: Nested action `← somethingBad` must be nested inside a `do` expression. -/
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#guard_msgs in
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#eval show MetaM Unit from do
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let t := if false then ← somethingBad else 9
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def foo : MetaM Bool :=
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return false
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/-- error: Nested action `← somethingBad` must be nested inside a `do` expression. -/
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#guard_msgs in
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#eval show MetaM Unit from do
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let t := if (← foo) then ← somethingBad else 9
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/--
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info: 1
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-/
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#guard_msgs in
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#eval show MetaM Nat from do
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let t := if (← foo) then 0 else 1
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return t
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