From c0d8b0abcb99adf5f7d2ddac3ad343d48da94910 Mon Sep 17 00:00:00 2001
From: Albert Krewinkel <albert@zeitkraut.de>
Date: Mon, 19 Nov 2018 21:36:02 +0100
Subject: [PATCH] Lua filters: test AST object equality via Haskell
Equality of Lua objects representing pandoc AST elements is tested by
unmarshalling the objects and comparing the result in Haskell. A new
function `equals` which performs this test has been added to the
`pandoc.utils` module.
Closes: #5092
---
data/pandoc.lua | 5 ++-
doc/lua-filters.md | 48 ++++++++++++++++++++++++++++-
src/Text/Pandoc/Lua/Module/Utils.hs | 18 +++++++++--
3 files changed, 66 insertions(+), 5 deletions(-)
diff --git a/data/pandoc.lua b/data/pandoc.lua
index e69f8ac9c..9289c177f 100644
--- a/data/pandoc.lua
+++ b/data/pandoc.lua
@@ -25,6 +25,7 @@ THIS SOFTWARE.
local M = {}
local List = require 'pandoc.List'
+local utils = require 'pandoc.utils'
------------------------------------------------------------------------
-- Accessor objects
@@ -119,6 +120,7 @@ local function create_accessor_behavior (tag, accessors)
'function (x, v) x.c%s = v end',
accessors
)
+ behavior.__eq = utils.equals
behavior.__index = function(t, k)
if getmetatable(t).getters[k] then
return getmetatable(t).getters[k](t)
@@ -873,6 +875,7 @@ function M.Attr:new (identifier, classes, attributes)
return {identifier, classes, attributes}
end
M.Attr.behavior._field_names = {identifier = 1, classes = 2, attributes = 3}
+M.Attr.behavior.__eq = utils.equals
M.Attr.behavior.__index = function(t, k)
return rawget(t, getmetatable(t)._field_names[k]) or
getmetatable(t)[k]
@@ -931,6 +934,7 @@ function M.ListAttributes:new (start, style, delimiter)
return {start, style, delimiter}
end
M.ListAttributes.behavior._field_names = {start = 1, style = 2, delimiter = 3}
+M.ListAttributes.behavior.__eq = utils.equals
M.ListAttributes.behavior.__index = function (t, k)
return rawget(t, getmetatable(t)._field_names[k]) or
getmetatable(t)[k]
@@ -1033,7 +1037,6 @@ M.UpperAlpha = "UpperAlpha"
------------------------------------------------------------------------
-- Functions which have moved to different modules
-local utils = require 'pandoc.utils'
M.sha1 = utils.sha1
return M
diff --git a/doc/lua-filters.md b/doc/lua-filters.md
index 57eb4e79c..b0d1884e8 100644
--- a/doc/lua-filters.md
+++ b/doc/lua-filters.md
@@ -171,7 +171,7 @@ variables.
: The name used to involve the filter. This value can be used
to find files relative to the script file. This variable is
also set in custom writers.
-
+
`PANDOC_STATE`
: The state shared by all readers and writers. It is used by
pandoc to collect and pass information. The value of this
@@ -641,6 +641,9 @@ to create these objects.
Pandoc document
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
`blocks`
: document content ([List] of [Block]s)
@@ -653,10 +656,16 @@ Pandoc document
Meta information on a document; string-indexed collection of
[MetaValue]s.
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
## MetaValue {#type-ref-MetaValue}
Document meta information items.
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
### MetaBlocks {#type-ref-MetaBlocks}
A list of blocks usable as meta value ([List] of [Block]s)
@@ -707,6 +716,9 @@ Plain Lua string value (string)
## Block {#type-ref-Block}
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
### BlockQuote {#type-ref-BlockQuote}
A block quote element
@@ -926,6 +938,9 @@ centered).
## Inline {#type-ref-Inline}
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
### Cite {#type-ref-Cite}
Citation
@@ -1166,6 +1181,9 @@ Superscripted text
A set of element attributes
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
`identifier`
: element identifier (string)
@@ -1184,6 +1202,9 @@ indices to the list table.
Single citation entry
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
`id`
: citation identifier, e.g., a bibtex key (string)
@@ -1206,6 +1227,9 @@ Single citation entry
### ListAttributes {#type-ref-ListAttributes}
List attributes
+Object equality is determined via
+[`pandoc.utils.equals`](#utils-equals).
+
`start`
: number of the first list item (integer)
@@ -2202,6 +2226,28 @@ functions.
-- pandoc.Emph{ pandoc.Str 'Paragraph2' }
-- }
+[`equals (element1, element2)`]{#utils-equals}
+
+: Test equality of AST elements. Elements in Lua are considered
+ equal if and only if the objects obtained by unmarshaling are
+ equal.
+
+ Parameters:
+
+ `element1`, `element2`:
+ : Objects to be compared. Acceptable input types are
+ [Pandoc](#type-ref-pandoc), [Meta](#type-ref-meta),
+ [MetaValue](#type-ref-MetaValue),
+ [Block](#type-ref-Block), [Inline](#type-ref-Inline),
+ [Attr](#type-ref-Attr),
+ [ListAttributes](#type-ref-ListAttributes), and
+ [Citation](#type-ref-Citation).
+
+ Returns:
+
+ - Whether the two objects represent the same element
+ (boolean)
+
[`hierarchicalize (blocks)`]{#utils-hierarchicalize}
: Convert list of blocks into an hierarchical list. An
diff --git a/src/Text/Pandoc/Lua/Module/Utils.hs b/src/Text/Pandoc/Lua/Module/Utils.hs
index 01762aebf..a75a2934b 100644
--- a/src/Text/Pandoc/Lua/Module/Utils.hs
+++ b/src/Text/Pandoc/Lua/Module/Utils.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE NoImplicitPrelude #-}
{-
Copyright © 2017-2018 Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
@@ -15,7 +16,6 @@ You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-}
-{-# LANGUAGE NoImplicitPrelude #-}
{- |
Module : Text.Pandoc.Lua.Module.Utils
Copyright : Copyright © 2017-2018 Albert Krewinkel
@@ -36,7 +36,8 @@ import Data.Char (toLower)
import Data.Default (def)
import Foreign.Lua (Peekable, Lua, NumResults)
import Text.Pandoc.Class (runIO, setUserDataDir)
-import Text.Pandoc.Definition (Pandoc, Meta, MetaValue (..), Block, Inline)
+import Text.Pandoc.Definition ( Pandoc, Meta, MetaValue (..), Block, Inline
+ , Citation, Attr, ListAttributes)
import Text.Pandoc.Lua.StackInstances ()
import Text.Pandoc.Lua.Util (addFunction)
@@ -52,6 +53,7 @@ pushModule :: Maybe FilePath -> Lua NumResults
pushModule mbDatadir = do
Lua.newtable
addFunction "blocks_to_inlines" blocksToInlines
+ addFunction "equals" equals
addFunction "hierarchicalize" hierarchicalize
addFunction "normalize_date" normalizeDate
addFunction "run_json_filter" (runJSONFilter mbDatadir)
@@ -112,7 +114,9 @@ stringify el = return $ case el of
InlineElement i -> Shared.stringify i
BlockElement b -> Shared.stringify b
MetaElement m -> Shared.stringify m
+ CitationElement c -> Shared.stringify c
MetaValueElement m -> stringifyMetaValue m
+ _ -> ""
stringifyMetaValue :: MetaValue -> String
stringifyMetaValue mv = case mv of
@@ -120,19 +124,27 @@ stringifyMetaValue mv = case mv of
MetaString s -> s
_ -> Shared.stringify mv
+equals :: AstElement -> AstElement -> Lua Bool
+equals e1 e2 = return (e1 == e2)
+
data AstElement
= PandocElement Pandoc
| MetaElement Meta
| BlockElement Block
| InlineElement Inline
| MetaValueElement MetaValue
- deriving (Show)
+ | AttrElement Attr
+ | ListAttributesElement ListAttributes
+ | CitationElement Citation
+ deriving (Eq, Show)
instance Peekable AstElement where
peek idx = do
res <- Lua.try $ (PandocElement <$> Lua.peek idx)
<|> (InlineElement <$> Lua.peek idx)
<|> (BlockElement <$> Lua.peek idx)
+ <|> (AttrElement <$> Lua.peek idx)
+ <|> (ListAttributesElement <$> Lua.peek idx)
<|> (MetaElement <$> Lua.peek idx)
<|> (MetaValueElement <$> Lua.peek idx)
case res of