48c7a4f7d9
This PR improves metavariable pretty printing and their hovers in the InfoView. The hovers in the InfoView now include information about specific metavariables — it includes information such as the kind of the metavariable, whether it is a blocked delayed assignment and which metavariables it is blocked on, and the differences in what variables exist the metavariable's local context. Additionally, named metavariables now pretty print with tombstones if they are inaccessible. Delayed assignment pretty printing now more reliably follows chains of assignments to find the pending metavariable. **Example hovers** Hovering over a natural metavariable: > `?m.7 : Sort ?u.14` > A metavariable representing an expression that should be solved for by unification during the elaboration process. They are created during elaboration as placeholders for implicit arguments and by `_` placeholder syntax. > > Variables absent from this metavariable's local context: `a`, `b`, `y` Hovering over `?baz`, a tactic goal: > `?baz : ∀ (a : ?m.7) (a : ?m.8), True` > A metavariable representing a tactic goal or an expression whose elaboration is still pending. They usually act like constants until they are completely solved for. They can be created using `?_` and `?n` synthetic placeholder syntax. > > Variables absent from this metavariable's local context: `a`, `b`, `y` Hovering over `?refine_1`, which appears under a binder: > `?m.4 x : Nat` > A metavariable representing a tactic goal or an expression whose elaboration is still pending. They usually act like constants until they are completely solved for. They can be created using `?_` and `?n` synthetic placeholder syntax. > > This metavariable appears here via a *delayed assignment*. Substitution is delayed until the metavariable's value contains no metavariables, since all occurrences of the variables from its local context will need to be replaced with expressions that are valid in the current context. > > Additional variable in this metavariable's local context: `x` Hovering over `?m.4`: > `?m.4 : Nat → Nat` > Part of the encoding of the *delayed assignment* mechanism. Represents the metavariable `?refine_1`, which has additional local context variables. Substitution is delayed until the metavariable's value contains no metavariables, since all occurrences of the variables from its local context will need to be replaced with expressions that are valid in the current context. > > Additional variable in this metavariable's local context: `x` The middle paragraph for `?refine_1` when it has been partially assigned: > This metavariable has been assigned, but it is a *delayed assignment*. Substitution is delayed until the metavariable's value contains no metavariables, since all occurrences of the variables from its local context will need to be replaced with expressions that are valid in the current context. Substitution is awaiting assignment of the following metavariable: `?foo`
8 lines
153 B
Text
8 lines
153 B
Text
let y := Nat.zero;
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y.add y
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fun y_1 => y.add y_1
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fun y => Nat.add FREE y
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fun (y : Nat) => Nat.add y y
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Nat.add ?m y
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Nat.add ?m #0
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fun y => (y.add y).add y
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