Implemented SoftBreak and new `--wrap` option.

Added threefold wrapping option.

* Command line option: deprecated `--no-wrap`, added
  `--wrap=[auto|none|preserve]`
* Added WrapOption, exported from Text.Pandoc.Options
* Changed type of writerWrapText in WriterOptions from
  Bool to WrapOption.
* Modified Text.Pandoc.Shared functions for SoftBreak.
* Supported SoftBreak in writers.
* Updated tests.
* Updated README.

Closes #1701.

1 files changed, 15 insertions, 14 deletions

diff --git a/tests/markdown-reader-more.native b/tests/markdown-reader-more.native
index 5ce8e98b6..0148e9394 100644
--- a/tests/markdown-reader-more.native
+++ b/tests/markdown-reader-more.native
@@ -1,4 +1,5 @@
-[Header 1 ("additional-markdown-reader-tests",[],[]) [Str "Additional",Space,Str "markdown",Space,Str "reader",Space,Str "tests"]
+[Para [Str "spanning",Space,Str "multiple",Space,Str "lines",SoftBreak,Str "%",Space,Str "Author",Space,Str "One",SoftBreak,Str "Author",Space,Str "Two;",Space,Str "Author",Space,Str "Three;",SoftBreak,Str "Author",Space,Str "Four"]
+,Header 1 ("additional-markdown-reader-tests",[],[]) [Str "Additional",Space,Str "markdown",Space,Str "reader",Space,Str "tests"]
 ,Header 2 ("blank-line-before-url-in-link-reference",[],[]) [Str "Blank",Space,Str "line",Space,Str "before",Space,Str "URL",Space,Str "in",Space,Str "link",Space,Str "reference"]
 ,Para [Link ("",[],[]) [Str "foo"] ("/url",""),Space,Str "and",Space,Link ("",[],[]) [Str "bar"] ("/url","title")]
 ,Header 2 ("raw-context-environments",[],[]) [Str "Raw",Space,Str "ConTeXt",Space,Str "environments"]
@@ -6,7 +7,7 @@
 ,RawBlock (Format "context") "\\startformula\n   L_{1} = L_{2}\n   \\stopformula"
 ,RawBlock (Format "context") "\\start[a2]\n\\start[a2]\n\\stop[a2]\n\\stop[a2]"
 ,Header 2 ("urls-with-spaces-and-punctuation",[],[]) [Str "URLs",Space,Str "with",Space,Str "spaces",Space,Str "and",Space,Str "punctuation"]
-,Para [Link ("",[],[]) [Str "foo"] ("/bar%20and%20baz",""),Space,Link ("",[],[]) [Str "foo"] ("/bar%20and%20baz",""),Space,Link ("",[],[]) [Str "foo"] ("/bar%20and%20baz",""),Space,Link ("",[],[]) [Str "foo"] ("bar%20baz","title")]
+,Para [Link ("",[],[]) [Str "foo"] ("/bar%20and%20baz",""),SoftBreak,Link ("",[],[]) [Str "foo"] ("/bar%20and%20baz",""),SoftBreak,Link ("",[],[]) [Str "foo"] ("/bar%20and%20baz",""),SoftBreak,Link ("",[],[]) [Str "foo"] ("bar%20baz","title")]
 ,Para [Link ("",[],[]) [Str "baz"] ("/foo%20foo",""),Space,Link ("",[],[]) [Str "bam"] ("/foo%20fee",""),Space,Link ("",[],[]) [Str "bork"] ("/foo/zee%20zob","title")]
 ,Para [Link ("",[],[]) [Str "Ward\8217s",Space,Str "method."] ("http://en.wikipedia.org/wiki/Ward's_method","")]
 ,Header 2 ("horizontal-rules-with-spaces-at-end",[],[]) [Str "Horizontal",Space,Str "rules",Space,Str "with",Space,Str "spaces",Space,Str "at",Space,Str "end"]
@@ -22,7 +23,7 @@
 ,Para [Str "$PATH",Space,Str "90",Space,Str "$PATH"]
 ,Header 2 ("commented-out-list-item",[],[]) [Str "Commented-out",Space,Str "list",Space,Str "item"]
 ,BulletList
- [[Plain [Str "one",Space,RawInline (Format "html") "<!--\n- two\n-->"]]
+ [[Plain [Str "one",SoftBreak,RawInline (Format "html") "<!--\n- two\n-->"]]
  ,[Plain [Str "three"]]]
 ,Header 2 ("indented-code-at-beginning-of-list",[],[]) [Str "Indented",Space,Str "code",Space,Str "at",Space,Str "beginning",Space,Str "of",Space,Str "list"]
 ,BulletList
@@ -90,9 +91,9 @@
  [[Plain [Str "col",Space,Str "1"]]
  ,[Plain [Str "col",Space,Str "2"]]
  ,[Plain [Str "col",Space,Str "3"]]]
- [[[Para [Str "r1",Space,Str "a",Space,Str "r1",Space,Str "bis"]]
-  ,[Para [Str "b",Space,Str "b",Space,Str "2"]]
-  ,[Para [Str "c",Space,Str "c",Space,Str "2"]]]
+ [[[Para [Str "r1",Space,Str "a",SoftBreak,Str "r1",Space,Str "bis"]]
+  ,[Para [Str "b",SoftBreak,Str "b",Space,Str "2"]]
+  ,[Para [Str "c",SoftBreak,Str "c",Space,Str "2"]]]
  ,[[Para [Str "r2",Space,Str "d"]]
   ,[Para [Str "e"]]
   ,[Para [Str "f"]]]]
@@ -101,9 +102,9 @@
  [[]
  ,[]
  ,[]]
- [[[Para [Str "r1",Space,Str "a",Space,Str "r1",Space,Str "bis"]]
-  ,[Para [Str "b",Space,Str "b",Space,Str "2"]]
-  ,[Para [Str "c",Space,Str "c",Space,Str "2"]]]
+ [[[Para [Str "r1",Space,Str "a",SoftBreak,Str "r1",Space,Str "bis"]]
+  ,[Para [Str "b",SoftBreak,Str "b",Space,Str "2"]]
+  ,[Para [Str "c",SoftBreak,Str "c",Space,Str "2"]]]
  ,[[Para [Str "r2",Space,Str "d"]]
   ,[Para [Str "e"]]
   ,[Para [Str "f"]]]]
@@ -112,9 +113,9 @@
  [[]
  ,[]
  ,[]]
- [[[Para [Str "r1",Space,Str "a",Space,Str "r1",Space,Str "bis"]]
-  ,[Para [Str "b",Space,Str "b",Space,Str "2"]]
-  ,[Para [Str "c",Space,Str "c",Space,Str "2"]]]
+ [[[Para [Str "r1",Space,Str "a",SoftBreak,Str "r1",Space,Str "bis"]]
+  ,[Para [Str "b",SoftBreak,Str "b",Space,Str "2"]]
+  ,[Para [Str "c",SoftBreak,Str "c",Space,Str "2"]]]
  ,[[Para [Str "r2",Space,Str "d"]]
   ,[Para [Str "e"]]
   ,[Para [Str "f"]]]]
@@ -135,7 +136,7 @@
     [[Plain [Str "b"]]
     ,[Plain [Str "b",Space,Str "2"]]
     ,[Plain [Str "b",Space,Str "2"]]]]
-  ,[Para [Str "c",Space,Str "c",Space,Str "2",Space,Str "c",Space,Str "2"]]]]
+  ,[Para [Str "c",SoftBreak,Str "c",Space,Str "2",SoftBreak,Str "c",Space,Str "2"]]]]
 ,Para [Str "Empty",Space,Str "cells"]
 ,Table [] [AlignDefault,AlignDefault] [5.555555555555555e-2,5.555555555555555e-2]
  [[]
@@ -156,7 +157,7 @@
 ,Header 2 ("reference-link-fallbacks",[],[]) [Str "Reference",Space,Str "link",Space,Str "fallbacks"]
 ,Para [Str "[",Emph [Str "not",Space,Str "a",Space,Str "link"],Str "]",Space,Str "[",Emph [Str "nope"],Str "]\8230"]
 ,Header 2 ("reference-link-followed-by-a-citation",[],[]) [Str "Reference",Space,Str "link",Space,Str "followed",Space,Str "by",Space,Str "a",Space,Str "citation"]
-,Para [Str "MapReduce",Space,Str "is",Space,Str "a",Space,Str "paradigm",Space,Str "popularized",Space,Str "by",Space,Link ("",[],[]) [Str "Google"] ("http://google.com",""),Space,Cite [Citation {citationId = "mapreduce", citationPrefix = [], citationSuffix = [], citationMode = NormalCitation, citationNoteNum = 0, citationHash = 0}] [Str "[@mapreduce]"],Space,Str "as",Space,Str "its",Space,Str "most",Space,Str "vocal",Space,Str "proponent."]
+,Para [Str "MapReduce",Space,Str "is",Space,Str "a",Space,Str "paradigm",Space,Str "popularized",Space,Str "by",Space,Link ("",[],[]) [Str "Google"] ("http://google.com",""),Space,Cite [Citation {citationId = "mapreduce", citationPrefix = [], citationSuffix = [], citationMode = NormalCitation, citationNoteNum = 0, citationHash = 0}] [Str "[@mapreduce]"],Space,Str "as",Space,Str "its",SoftBreak,Str "most",Space,Str "vocal",Space,Str "proponent."]
 ,Header 2 ("empty-reference-links",[],[]) [Str "Empty",Space,Str "reference",Space,Str "links"]
 ,Para [Str "bar"]
 ,Para [Link ("",[],[]) [Str "foo2"] ("","")]