lean4-htt/src/Lean/Elab/Notation.lean
Leonardo de Moura 799c701f56 fix: inconsistency between syntax and kind names
TODO: remove staging workarounds

see #1090
2022-04-01 11:20:16 -07:00

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/-
Copyright (c) 2021 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
import Lean.Elab.Syntax
import Lean.Elab.AuxDef
namespace Lean.Elab.Command
open Lean.Syntax
open Lean.Parser.Term hiding macroArg
open Lean.Parser.Command
/- Wrap all occurrences of the given `ident` nodes in antiquotations -/
private partial def antiquote (vars : Array Syntax) : Syntax → Syntax
| stx => match stx with
| `($id:ident) =>
if (vars.findIdx? (fun var => var.getId == id.getId)).isSome then
mkAntiquotNode id
else
stx
| _ => match stx with
| Syntax.node i k args => Syntax.node i k (args.map (antiquote vars))
| stx => stx
/- Convert `notation` command lhs item into a `syntax` command item -/
def expandNotationItemIntoSyntaxItem (stx : Syntax) : MacroM Syntax :=
let k := stx.getKind
if k == `Lean.Parser.Command.identPrec then
pure $ mkNode `Lean.Parser.Syntax.cat #[mkIdentFrom stx `term, stx[1]]
else if k == strLitKind then
pure $ mkNode `Lean.Parser.Syntax.atom #[stx]
else
Macro.throwUnsupported
/- Convert `notation` command lhs item into a pattern element -/
def expandNotationItemIntoPattern (stx : Syntax) : MacroM Syntax :=
let k := stx.getKind
if k == `Lean.Parser.Command.identPrec then
return mkAntiquotNode stx[0]
else if k == strLitKind then
strLitToPattern stx
else
Macro.throwUnsupported
/-- Try to derive a `SimpleDelab` from a notation.
The notation must be of the form `notation ... => c var_1 ... var_n`
where `c` is a declaration in the current scope and the `var_i` are a permutation of the LHS vars. -/
def mkSimpleDelab (attrKind : Syntax) (vars : Array Syntax) (pat qrhs : Syntax) : OptionT MacroM Syntax := do
match qrhs with
| `($c:ident $args*) =>
let [(c, [])] ← Macro.resolveGlobalName c.getId | failure
guard <| args.all (Syntax.isIdent ∘ getAntiquotTerm)
guard <| args.allDiff
-- replace head constant with (unused) antiquotation so we're not dependent on the exact pretty printing of the head
-- The reference is attached to the syntactic representation of the called function itself, not the entire function application
`(@[$attrKind:attrKind appUnexpander $(mkIdent c):ident]
aux_def unexpand $(mkIdent c) : Lean.PrettyPrinter.Unexpander := fun
| `($$f:ident $args*) => withRef f `($pat)
| _ => throw ())
| `($c:ident) =>
let [(c, [])] ← Macro.resolveGlobalName c.getId | failure
`(@[$attrKind:attrKind appUnexpander $(mkIdent c):ident]
aux_def unexpand $(mkIdent c) : Lean.PrettyPrinter.Unexpander := fun
| `($$f:ident) => withRef f `($pat)
| _ => throw ())
| _ => failure
private def isLocalAttrKind (attrKind : Syntax) : Bool :=
match attrKind with
| `(Parser.Term.attrKind| local) => true
| _ => false
private def expandNotationAux (ref : Syntax)
(currNamespace : Name) (attrKind : Syntax) (prec? : Option Syntax) (name? : Option Syntax) (prio? : Option Syntax) (items : Array Syntax) (rhs : Syntax) : MacroM Syntax := do
let prio ← evalOptPrio prio?
-- build parser
let syntaxParts ← items.mapM expandNotationItemIntoSyntaxItem
let cat := mkIdentFrom ref `term
let name ←
match name? with
| some name => pure name.getId
| none => mkNameFromParserSyntax `term (mkNullNode syntaxParts)
-- build macro rules
let vars := items.filter fun item => item.getKind == `Lean.Parser.Command.identPrec
let vars := vars.map fun var => var[0]
let qrhs := antiquote vars rhs
let patArgs ← items.mapM expandNotationItemIntoPattern
/- The command `syntax [<kind>] ...` adds the current namespace to the syntax node kind.
So, we must include current namespace when we create a pattern for the following `macro_rules` commands. -/
let fullName := currNamespace ++ name
let pat := mkNode fullName patArgs
let stxDecl ← `($attrKind:attrKind syntax $[: $prec?]? (name := $(mkIdent name)) (priority := $(quote prio):num) $[$syntaxParts]* : $cat)
let mut macroDecl ← `(macro_rules | `($pat) => ``($qrhs))
if isLocalAttrKind attrKind then
-- Make sure the quotation pre-checker takes section variables into account for local notation.
macroDecl ← `(section set_option quotPrecheck.allowSectionVars true $macroDecl end)
match (← mkSimpleDelab attrKind vars pat qrhs |>.run) with
| some delabDecl => return mkNullNode #[stxDecl, macroDecl, delabDecl]
| none => return mkNullNode #[stxDecl, macroDecl]
@[builtinMacro Lean.Parser.Command.notation] def expandNotation : Macro
| stx@`($attrKind:attrKind notation $[: $prec? ]? $[(name := $name?)]? $[(priority := $prio?)]? $items* => $rhs) => do
-- trigger scoped checks early and only once
let _ ← toAttributeKind attrKind
expandNotationAux stx (← Macro.getCurrNamespace) attrKind prec? name? prio? items rhs
| _ => Macro.throwUnsupported
end Lean.Elab.Command