c9727c2d19
This PR allows Lean's parser to run with a final position prior to the end of the string, so it can be invoked on a sub-region of the input. This has applications in Verso proper, which parses Lean syntax in contexts such as code blocks and docstrings, and it is a prerequisite to parsing the contents of Lean docstrings.
59 lines
1.5 KiB
Text
59 lines
1.5 KiB
Text
import Lean.Elab.Command
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open Lean Elab Command Parser
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declare_syntax_cat balanced
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syntax "!" : balanced
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syntax "(" balanced* ")" : balanced
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elab d:docComment "test" : command => do
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let some ⟨pos, endPos⟩ := d.raw[1].getRange? (canonicalOnly := true)
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| throwErrorAt d "Docstring doesn't have a canonical position"
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let p := Parser.categoryParser `balanced 0
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let p := andthenFn whitespace p.fn
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let text ← getFileMap
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let input := text.source
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let endPos := input.prev <| input.prev endPos
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if h : endPos ≤ input.endPos then
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let ictx := mkInputContext input (← getFileName) (endPos := endPos) (endPos_valid := h)
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let env ← getEnv
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let s := { mkParserState input with pos }
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let s := p.run ictx { env, options := {} } (getTokenTable env) s
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if !s.allErrors.isEmpty then
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for (pos, _, err) in s.allErrors do
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logMessage {
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fileName := (← getFileName )
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pos := text.toPosition pos
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endPos := some (text.toPosition endPos)
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data := s!"{err.toString}"
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}
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else if ictx.atEnd s.pos then
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logInfo s.stxStack.back
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else
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let pos := s.pos
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logMessage {
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fileName := (← getFileName )
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pos := text.toPosition pos
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endPos := some (text.toPosition endPos)
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data := s!"expected end of input"
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}
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else
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throwError "Out of bounds"
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/-- info: (!!(!)) -/
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#guard_msgs in
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/--
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( ! ! (!) )
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-/
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test
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/-- error: unexpected end of input; expected ')' -/
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#guard_msgs in
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/--
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(
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-/
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test
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