Hack to unescape \n

src/preserves/parse.nim

@@ -74,7 +74,7 @@ proc parsePreserves*(text: string): Preserve[void] {.gcsafe.} =
       pushStack Value(kind: pkSignedInteger, int: parseInt($0))
 
     Preserves.String <- Preserves.String:
-      pushStack Value(kind: pkString, string: unescape($0))
+      pushStack Value(kind: pkString, string: unescape($0).replace("\\n", "\n"))
 
     Preserves.charByteString <- Preserves.charByteString:
       let s = unescape($1)

src/preserves/private/preserves_encode.nim

@@ -1,10 +1,10 @@
 # SPDX-FileCopyrightText: 2021 ☭ Emery Hemingway
 # SPDX-License-Identifier: Unlicense
 
-import std/[json, options, streams]
+import std/[json, options, streams, xmlparser, xmltree]
 from std/os import extractFilename, paramStr
 
-import ../../preserves, ../../preserves/jsonhooks, ../../preserves/parse
+import ../../preserves, ../jsonhooks, ../parse, ../xmlhooks
 
 when isMainModule:
   let command = extractFilename(paramStr 0)
@@ -21,6 +21,11 @@ when isMainModule:
         js = stdin.newFileStream.parseJson
         pr = js.toPreserve
       stdout.newFileStream.write(pr)
+    of "preserves_from_xml":
+      let
+        xn = stdin.newFileStream.parseXml
+        pr = xn.toPreserveHook(void)
+      stdout.newFileStream.write(pr)
     of "preserves_to_json":
       let
         pr = stdin.readAll.decodePreserves
@@ -29,6 +34,13 @@ when isMainModule:
         stdout.writeLine(get js)
       else:
         quit("Preserves not convertable to JSON")
+    of "preserves_to_xml":
+      let pr = stdin.readAll.decodePreserves
+      var xn: XmlNode
+      if fromPreserveHook(xn, pr):
+        stdout.writeLine(xn)
+      else:
+        quit("Preserves not convertable to XML")
     else:
       quit("no behavior defined for " & command)
   except:

src/preserves/xmlhooks.nim

@@ -0,0 +1,72 @@
+# SPDX-FileCopyrightText: 2021 ☭ Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+import std/[xmltree, strtabs, tables]
+import ../preserves
+
+proc toPreserveHook*(xn: XmlNode; E: typedesc): Preserve[E] =
+  case xn.kind
+  of xnElement:
+    var children = initSequence[E](xn.len)
+    var i: int
+    for child in xn.items:
+      children[i] = toPreserveHook(child, E)
+      inc i
+    var attrMap = initDictionary[E]()
+    if not xn.attrs.isNil:
+      for key, val in xn.attrs.pairs:
+        attrMap[toSymbol(key, E)] = toPreserve(val, E)
+    result = initRecord[E](xn.tag, attrMap, children)
+  of xnText:
+    result = toPreserve(xn.text, E)
+  of xnVerbatimText:
+    result = initRecord[E]("verbatim", xn.text.toPreserve(E))
+  of xnComment:
+    result = initRecord[E]("comment", xn.text.toPreserve(E))
+  of xnCData:
+    result = initRecord[E]("cdata", xn.text.toPreserve(E))
+  of xnEntity:
+    result = initRecord[E]("entity", xn.text.toPreserve(E))
+
+proc fromPreserveHook*[E](xn: var XmlNode; pr: Preserve[E]): bool =
+  case pr.kind:
+  of pkString:
+    xn = newText(pr.string)
+    result = true
+  of pkRecord:
+    if pr.len == 2 and pr[0].isDictionary and pr[1].isSequence and pr.label.isSymbol:
+      xn = newElement(pr[2].symbol)
+      result = true
+      if pr[0].len > 0:
+        var attrs = newStringTable()
+        for key, val in pr[0].dict.items:
+          if not (key.isSymbol and val.isString):
+            result = false
+            break
+          attrs[key.symbol] = val.string
+        xn.attrs = attrs
+      var child: XmlNode
+      for e in pr[1]:
+        result = fromPreserveHook(child, e)
+        if not result: break
+        xn.add(move child)
+      if not result: reset xn
+    elif pr.len == 1 and pr.label.isSymbol:
+      result = true
+      case pr.label.symbol:
+      of "verbatim":
+        xn = newVerbatimText(pr[0].string)
+      of "comment":
+        xn = newComment(pr[0].string)
+      of "cdata":
+        xn = newCData(pr[0].string)
+      of "entity":
+        xn = newEntity(pr[0].string)
+      else:
+        result = false
+  else: discard
+
+when isMainModule:
+  var xn = XmlNode()
+  var pr = xn.toPreserveHook(void)
+  assert fromPreserveHook(xn, pr)

tests/test_conversions.nim

@@ -1,8 +1,8 @@
 # SPDX-FileCopyrightText: 2021 ☭ Emery Hemingway
 # SPDX-License-Identifier: Unlicense
 
-import std/[options, tables, unittest]
-import preserves
+import std/[options, tables, unittest, xmlparser, xmltree]
+import preserves, preserves/xmlhooks
 
 suite "conversions":
   test "dictionary":
@@ -40,7 +40,26 @@ suite "conversions":
     check(fromPreserve(c, b))
     check(a == c)
 
-suite "%":
+  test "XML":
+    var a: XmlNode
+    var b = parseXML """
+      <?xml version="1.0" standalone="no"?>
+      <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+      <?xml version="1.0"?>
+      <svg xmlns="http://www.w3.org/2000/svg" width="10cm" height="3cm" viewBox="0 0 1000 300" version="1.1">
+        <desc>Example text01 - 'Hello, out there' in blue</desc>
+        <text x="250" y="150" font-family="Verdana" font-size="55" fill="blue">
+      Hello, out there
+      </text>
+        <!-- Show outline of canvas using 'rect' element -->
+        <rect x="1" y="1" width="998" height="298" fill="none" stroke="blue" stroke-width="2"/>
+      </svg>
+    """
+    var pr = toPreserve(b, void)
+    checkpoint $pr
+    check fromPreserve(a, pr)
+
+suite "toPreserve":
   template check(p: Preserve; s: string) =
     test s: check($p == s)
   check false.toPreserve, "#f"