Lua: add functions pandoc.text.toencoding, pandoc.text.fromencoding.

Closes: #8512

doc/lua-filters.md

@@ -2418,6 +2418,18 @@ function Str (s)
 end
 ```
 
+### fromencoding {#text.fromencoding}
+
+`fromencoding(s, encoding)`
+
+Converts a string to UTF-8. The `encoding` parameter specifies the
+encoding of the input string. On Windows, that parameter defaults
+to the current ANSI code page; on other platforms the function
+will try to use the file system's encoding.
+
+See [`toencoding`](#text.toencoding) for more info on supported
+encodings.
+
 ### lower {#text.lower}
 
 `lower (s)`
@@ -2449,6 +2461,19 @@ Returns the length of a UTF-8 string.
 Returns a substring of a UTF-8 string, using Lua's string
 indexing rules.
 
+### toencoding {#text.toencoding}
+
+`toencoding(s, encoding)`
+
+Converts a UTF-8 string to a different encoding. The `encoding`
+parameter defaults to the current ANSI code page on Windows; on
+other platforms it will try to guess the file system's encoding.
+
+The set of known encodings is system dependent, but includes at
+least `UTF-8`, `UTF-16BE`, `UTF-16LE`, `UTF-32BE`, and `UTF-32LE`.
+Note that the default code page on Windows is available through
+`CP0`.
+
 # Module pandoc
 
 Fields and functions for pandoc scripts; includes constructors for

pandoc-lua-engine/pandoc-lua-engine.cabal

@@ -105,7 +105,7 @@ library
                      , hslua-module-doclayout>= 1.0.4   && < 1.1
                      , hslua-module-path     >= 1.0.3   && < 1.1
                      , hslua-module-system   >= 1.0     && < 1.1
-                     , hslua-module-text     >= 1.0     && < 1.1
+                     , hslua-module-text     >= 1.0.3   && < 1.1
                      , hslua-module-version  >= 1.0.3   && < 1.1
                      , hslua-module-zip      >= 1.0.0   && < 1.1
                      , lpeg                  >= 1.0.1   && < 1.1

stack.yaml

@@ -23,6 +23,7 @@ extra-deps:
 - hslua-core-2.2.1
 - hslua-list-1.1.0
 - hslua-marshalling-2.2.1
+- hslua-module-text-1.0.3
 - hslua-module-version-1.0.3
 - hslua-module-zip-1.0.0
 - hslua-objectorientation-2.2.1