bookshelf/DocGen4/Output/ToHtmlFormat.lean

150 lines
5.1 KiB
Plaintext
Raw Blame History

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

/-
Copyright (c) 2021 Wojciech Nawrocki. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Wojciech Nawrocki, Sebastian Ullrich, Henrik Böving
-/
import Lean.Data.Json
import Lean.Parser
/-! This module defines:
- a representation of HTML trees
- together with a JSX-like DSL for writing them
- and widget support for visualizing any type as HTML. -/
namespace DocGen4
open Lean
inductive Html where
-- TODO(WN): it's nameless for shorter JSON; re-add names when we have deriving strategies for From/ToJson
-- element (tag : String) (flatten : Bool) (attrs : Array HtmlAttribute) (children : Array Html)
| element : String → Bool → Array (String × String) → Array Html → Html
| text : String → Html
deriving Repr, BEq, Inhabited, FromJson, ToJson
instance : Coe String Html :=
⟨Html.text⟩
namespace Html
def attributesToString (attrs : Array (String × String)) :String :=
attrs.foldl (fun acc (k, v) => acc ++ " " ++ k ++ "=\"" ++ v ++ "\"") ""
-- TODO: Termination proof
partial def toStringAux : Html → String
| element tag false attrs #[text s] => s!"<{tag}{attributesToString attrs}>{s}</{tag}>\n"
| element tag false attrs #[child] => s!"<{tag}{attributesToString attrs}>\n{child.toStringAux}</{tag}>\n"
| element tag false attrs children => s!"<{tag}{attributesToString attrs}>\n{children.foldl (· ++ toStringAux ·) ""}</{tag}>\n"
| element tag true attrs children => s!"<{tag}{attributesToString attrs}>{children.foldl (· ++ toStringAux ·) ""}</{tag}>"
| text s => s
def toString (html : Html) : String :=
html.toStringAux.trimRight
instance : ToString Html :=
⟨toString⟩
partial def textLength : Html → Nat
| text s => s.length
| element _ _ _ children =>
let lengths := children.map textLength
lengths.foldl Nat.add 0
def escapePairs : Array (String × String) :=
#[
("&", "&amp;"),
("<", "&lt;"),
(">", "&gt;"),
("\"", "&quot;")
]
def escape (s : String) : String :=
escapePairs.foldl (fun acc (o, r) => acc.replace o r) s
end Html
namespace Jsx
open Parser PrettyPrinter
declare_syntax_cat jsxElement
declare_syntax_cat jsxChild
-- JSXTextCharacter : SourceCharacter but not one of {, <, > or }
def jsxText : Parser :=
withAntiquot (mkAntiquot "jsxText" `jsxText) {
fn := fun c s =>
let startPos := s.pos
let s := takeWhile1Fn (not ∘ "[{<>}]$".contains) "expected JSX text" c s
mkNodeToken `jsxText startPos c s }
@[combinator_formatter DocGen4.Jsx.jsxText] def jsxText.formatter : Formatter := pure ()
@[combinator_parenthesizer DocGen4.Jsx.jsxText] def jsxText.parenthesizer : Parenthesizer := pure ()
syntax jsxAttrName := rawIdent <|> str
syntax jsxAttrVal := str <|> group("{" term "}")
syntax jsxSimpleAttr := jsxAttrName "=" jsxAttrVal
syntax jsxAttrSpread := "[" term "]"
syntax jsxAttr := jsxSimpleAttr <|> jsxAttrSpread
syntax "<" rawIdent jsxAttr* "/>" : jsxElement
syntax "<" rawIdent jsxAttr* ">" jsxChild* "</" rawIdent ">" : jsxElement
syntax jsxText : jsxChild
syntax "{" term "}" : jsxChild
syntax "[" term "]" : jsxChild
syntax jsxElement : jsxChild
scoped syntax:max jsxElement : term
def translateAttrs (attrs : Array (TSyntax `DocGen4.Jsx.jsxAttr)) : MacroM (TSyntax `term) := do
let mut as ← `(#[])
for attr in attrs.map TSyntax.raw do
as ← match attr with
| `(jsxAttr| $n:jsxAttrName=$v:jsxAttrVal) =>
let n ← match n with
| `(jsxAttrName| $n:str) => pure n
| `(jsxAttrName| $n:ident) => pure <| quote (toString n.getId)
| _ => Macro.throwUnsupported
let v ← match v with
| `(jsxAttrVal| {$v}) => pure v
| `(jsxAttrVal| $v:str) => pure v
| _ => Macro.throwUnsupported
`(($as).push ($n, ($v : String)))
| `(jsxAttr| [$t]) => `($as ++ ($t : Array (String × String)))
| _ => Macro.throwUnsupported
return as
private def htmlHelper (n : Syntax) (children : Array Syntax) (m : Syntax) : MacroM (String × (TSyntax `term)):= do
unless n.getId == m.getId do
withRef m <| Macro.throwError s!"Leading and trailing part of tags don't match: '{n}', '{m}'"
let mut cs ← `(#[])
for child in children do
cs ← match child with
| `(jsxChild|$t:jsxText) => `(($cs).push (Html.text $(quote t.raw[0]!.getAtomVal)))
-- TODO(WN): elab as list of children if type is `t Html` where `Foldable t`
| `(jsxChild|{$t}) => `(($cs).push ($t : Html))
| `(jsxChild|[$t]) => `($cs ++ ($t : Array Html))
| `(jsxChild|$e:jsxElement) => `(($cs).push ($e:jsxElement : Html))
| _ => Macro.throwUnsupported
let tag := toString n.getId
pure <| (tag, cs)
macro_rules
| `(<$n $attrs* />) => do
let kind := quote (toString n.getId)
let attrs ← translateAttrs attrs
`(Html.element $kind true $attrs #[])
| `(<$n $attrs* >$children*</$m>) => do
let (tag, children) ← htmlHelper n children m
`(Html.element $(quote tag) true $(← translateAttrs attrs) $children)
end Jsx
/-- A type which implements `ToHtmlFormat` will be visualized
as the resulting HTML in editors which support it. -/
class ToHtmlFormat (α : Type u) where
formatHtml : α → Html
end DocGen4