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Support WikiLink titles (#221)
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With this patch wiki links of the form [[doc#heading|title]]
are correctly recognized as links to doc#heading.
Also go-to-definition works as normal.

This fixes #136.
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@eguiraud
eguiraud authored Jun 20, 2023
1 parent dfe2bda commit 35bdaeb
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Showing 3 changed files with 178 additions and 90 deletions.
199 changes: 110 additions & 89 deletions Marksman/Parser.fs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,8 +19,9 @@ module Markdown =
type WikiLinkInline
(
text: string,
doc: Option<string * SourceSpan>,
heading: option<string * SourceSpan>
doc: option<string * SourceSpan>,
heading: option<string * SourceSpan>,
title: option<string * SourceSpan>
) =
inherit LeafInline()
member val Text = text
Expand All @@ -31,6 +32,9 @@ module Markdown =
member val Heading = Option.map fst heading
member val HeadingSpan = Option.map snd heading

member val Title = Option.map fst title
member val TitleSpan = Option.map snd title

type TagInline(text: string) =
inherit LeafInline()

Expand Down Expand Up @@ -63,105 +67,122 @@ module Markdown =
else
false


/// <summary>Match links of the form `[[doc#heading|title]]`, where at least one of `doc` and `#heading` must be present (`|title` may be omitted).</summary>
type WikiLinkParser() as this =
inherit InlineParser()

do this.OpeningCharacters <- [| '[' |]

override this.Match(processor, slice) =
let nextChar = slice.PeekCharExtra(1)
override this.Match(processor, slice_) =
let mutable docSpan: option<SourceSpan> = None
let mutable headingSpan: option<SourceSpan> = None
let mutable titleSpan: option<SourceSpan> = None

let mutable slice = slice_ // this copy is necessary because byrefs cannot be captured

// helper functions for finite state machine
let updateSpanEnd offset (span: option<SourceSpan>) =
span |> Option.map (fun s -> SourceSpan(s.Start, offset - 1))

let isNotEscaped () = slice.PeekCharExtra(-1) <> '\\'
let advance () = (slice.NextChar(), processor.GetSourcePosition(slice.Start))

// state transition functions
let parseEnd () =
let c, _ = advance ()
c = ']'

let rec parseTitle () =
let c, offset = advance ()

if titleSpan.IsNone then
titleSpan <- SourceSpan(offset, -1) |> Some

match c with
| ']' when isNotEscaped () ->
titleSpan <- updateSpanEnd offset titleSpan
parseEnd ()
| c when c.IsNewLineOrLineFeed() || c.IsZero() -> false
| _ -> parseTitle ()

let rec parseHeading () =
let c, offset = advance ()

if headingSpan.IsNone then
headingSpan <- SourceSpan(offset, -1) |> Some

match c with
| '|' when isNotEscaped () ->
headingSpan <- updateSpanEnd offset headingSpan
parseTitle ()
| ']' when isNotEscaped () ->
headingSpan <- updateSpanEnd offset headingSpan
parseEnd ()
| c when c.IsNewLineOrLineFeed() || c.IsZero() -> false
| _ -> parseHeading ()

let rec parseDoc offset =
if docSpan.IsNone then
docSpan <- SourceSpan(offset, -1) |> Some

let c, offset = advance ()

match c with
| '#' when isNotEscaped () ->
docSpan <- updateSpanEnd offset docSpan
parseHeading ()
| '|' when isNotEscaped () ->
docSpan <- updateSpanEnd offset docSpan
parseTitle ()
| ']' when isNotEscaped () ->
docSpan <- updateSpanEnd offset docSpan
parseEnd ()
| c when c.IsNewLineOrLineFeed() || c.IsZero() -> false
| _ -> parseDoc offset

let parse () =
let c, _ = advance ()

if c <> '[' then
false
else
let c, offset = advance ()

let isRef = nextChar = '['
match c with
| '#' -> parseHeading ()
| '|' -> parseTitle ()
| ']' -> parseEnd ()
| _ -> parseDoc offset

if isRef then
let start = slice.Start
let offsetStart = processor.GetSourcePosition(start)
let offsetInnerStart = offsetStart + 2
// do the parsing (run the finite state machine)
let start = slice.Start
let offsetStart = processor.GetSourcePosition(start)
let hasParsedLink = parse ()
slice_ <- slice // update output parameter to modified slice state

let mutable offsetHashDelim: option<int> = None
let mutable found = false
let mutable current = slice.NextChar()
if hasParsedLink then
let offsetEnd = processor.GetSourcePosition(slice.Start)
let text = slice.Text.Substring(start, offsetEnd - offsetStart + 1)

let shouldStop (c: char) = c.IsNewLineOrLineFeed() || c.IsZero() || found
let contentAndSpan (span: SourceSpan) =
let contentSliceStart = start + (span.Start - offsetStart)
let contentSliceLen = span.End - span.Start + 1
let content = slice.Text.Substring(contentSliceStart, contentSliceLen)

while not (shouldStop current) do
if
current = '#'
&& slice.PeekCharExtra(-1) <> '\\'
&& offsetHashDelim.IsNone
then
offsetHashDelim <- Some(processor.GetSourcePosition(slice.Start))
(content, span)

if current = ']' then
let prev = slice.PeekCharExtra(-1)
let link =
WikiLinkInline(
text,
Option.map contentAndSpan docSpan,
Option.map contentAndSpan headingSpan,
Option.map contentAndSpan titleSpan
)

if prev = ']' then found <- true else current <- slice.NextChar()
else
current <- slice.NextChar()

if found then
let end_ = slice.Start
let offsetEnd = offsetStart + (end_ - start)
let offsetInnerEnd = offsetEnd - 2

let text = slice.Text.Substring(start, end_ - start + 1)

let doc, heading =
match offsetHashDelim with
| Some offsetHashDelim ->
let offsetDocStart = offsetInnerStart
let offsetDocEnd = offsetHashDelim - 1
let offsetHeadingStart = offsetHashDelim + 1
let offsetHeadingEnd = offsetInnerEnd

let docText =
if offsetDocEnd >= offsetDocStart then
slice.Text.Substring(
start + 2,
offsetDocEnd - offsetDocStart + 1
)
else
String.Empty

let headingText =
if offsetHeadingEnd >= offsetHeadingStart then
slice.Text.Substring(
start + 2 + (offsetDocEnd - offsetDocStart + 1) + 1,
offsetHeadingEnd - offsetHeadingStart + 1
)
else
String.Empty

let doc =
if String.IsNullOrEmpty docText then
None
else
(docText, SourceSpan(offsetDocStart, offsetDocEnd)) |> Some

let heading =
(headingText, SourceSpan(offsetHeadingStart, offsetHeadingEnd))
|> Some

doc, heading

| None ->
let offsetDocStart = offsetStart + 2
let offsetDocEnd = offsetEnd - 2

let docText =
slice.Text.Substring(start + 2, offsetDocEnd - offsetDocStart + 1)

Some(docText, SourceSpan(offsetDocStart, offsetDocEnd)), None


let link = WikiLinkInline(text, doc, heading)
link.Span <- SourceSpan(offsetStart, offsetEnd)
processor.Inline <- link

found
else
false
link.Span <- SourceSpan(offsetStart, offsetEnd)
processor.Inline <- link

hasParsedLink

let markdigPipeline =
let pipelineBuilder =
Expand Down
37 changes: 36 additions & 1 deletion Tests/ParserTests.fs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -109,7 +109,7 @@ module WikiLinkTests =
checkSnapshot document

[<Fact>]
let parser_wiki_empty_heading () =
let parse_wiki_empty_heading () =
// 0123456
let text = "[[T#]]"
let doc = scrapeString text
Expand Down Expand Up @@ -141,6 +141,41 @@ module WikiLinkTests =
let doc = scrapeString text
checkSnapshot doc

[<Fact>]
let parse_wiki_with_title () =
// 0123456789012345
let text = "[[T#head|title]]"
let doc = scrapeString text
checkSnapshot doc

[<Fact>]
let parse_wiki_empty_title () =
// 0123456789012345
let text = "[[T#head|]]"
let doc = scrapeString text
checkSnapshot doc

[<Fact>]
let parse_wiki_no_doc_and_title () =
// 0123456789012345
let text = "[[#head|title]]"
let doc = scrapeString text
checkSnapshot doc

[<Fact>]
let parse_wiki_no_doc_and_no_title () =
// 0123456789012345
let text = "[[|]]"
let doc = scrapeString text
checkSnapshot doc

[<Fact>]
let parse_wiki_all_empty () =
// 0123456789012345
let text = "[[]]"
let doc = scrapeString text
checkSnapshot doc

[<Fact>]
let complex_example_1 () =
let text =
Expand Down
32 changes: 32 additions & 0 deletions Tests/_snapshots/WikiLinkTests.json
View file
Original file line number Diff line number Diff line change
Expand Up @@ -42,5 +42,37 @@
" doc=F\\#; (0,2)-(0,5)",
" head=Section #3; (0,6)-(0,16)"
]
},
"parse_wiki_all_empty": {
"AutoGenerated": [
"WL: [[]]; (0,0)-(0,4)",
" "
]
},
"parse_wiki_no_doc_and_title": {
"AutoGenerated": [
"WL: [[#head|title]]; (0,0)-(0,15)",
" head=head; (0,3)-(0,7)"
]
},
"parse_wiki_with_title": {
"AutoGenerated": [
"WL: [[T#head|title]]; (0,0)-(0,16)",
" doc=T; (0,2)-(0,3)",
" head=head; (0,4)-(0,8)"
]
},
"parse_wiki_no_doc_and_no_title": {
"AutoGenerated": [
"WL: [[|]]; (0,0)-(0,5)",
" "
]
},
"parse_wiki_empty_title": {
"AutoGenerated": [
"WL: [[T#head|]]; (0,0)-(0,11)",
" doc=T; (0,2)-(0,3)",
" head=head; (0,4)-(0,8)"
]
}
}

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