Custom reader: pass list of sources instead of concatenated text

The first argument passed to Lua `Reader` functions is no longer a plain
string but a richer data structure. The structure can easily be
converted to a string by applying `tostring`, but is also a list with
elements that contain each the *text* and *name* of each input source as
a property of the respective name.

A small example is added to the custom reader documentation, showcasing
its use in a reader that creates a syntax-highlighted code block for
each source code file passed as input.

Existing readers must be updated.

1 files changed, 1 insertions, 1 deletions

diff --git a/data/creole.lua b/data/creole.lua
index 5b7d7f554..590dfc871 100644
--- a/data/creole.lua
+++ b/data/creole.lua
@@ -186,5 +186,5 @@ G = P{ "Doc",
 }
 
 function Reader(input, reader_options)
-  return lpeg.match(G, input)
+  return lpeg.match(G, tostring(input))
 end