vis-digraph: add utility to handle digraphs

Hook it up via Lua to <C-k> in insert and replace mode.

Close martanne#460 martanne#475

.gitignore

@@ -4,6 +4,7 @@
 /vis
 /vis-menu
 /vis-single
+/vis-digraph
 *.css
 *.gcda
 *.gcno

Makefile

@@ -7,7 +7,7 @@ SRC = array.c buffer.c libutf.c main.c map.c register.c ring-buffer.c \
 	ui-curses.c view.c vis.c vis-lua.c vis-modes.c vis-motions.c \
 	vis-operators.c vis-prompt.c vis-text-objects.c $(REGEX_SRC)
 
-EXECUTABLES = vis vis-clipboard vis-complete vis-menu vis-open
+EXECUTABLES = vis vis-clipboard vis-complete vis-menu vis-digraph vis-open
 
 MANUALS = $(EXECUTABLES:=.1)
 
@@ -44,7 +44,7 @@ LDFLAGS_VIS = $(LDFLAGS_AUTO) $(LDFLAGS_TERMKEY) $(LDFLAGS_CURSES) $(LDFLAGS_ACL
 
 STRIP?=strip
 
-all: vis vis-menu
+all: vis vis-menu vis-digraph
 
 config.h:
 	cp config.def.h config.h
@@ -58,6 +58,9 @@ vis: config.h config.mk *.c *.h
 vis-menu: vis-menu.c
 	${CC} ${CFLAGS} ${CFLAGS_AUTO} ${CFLAGS_STD} ${CFLAGS_EXTRA} $< ${LDFLAGS} ${LDFLAGS_STD} ${LDFLAGS_AUTO} -o $@
 
+vis-digraph: vis-digraph.c
+	${CC} ${CFLAGS} ${CFLAGS_AUTO} ${CFLAGS_STD} ${CFLAGS_EXTRA} $< ${LDFLAGS} ${LDFLAGS_STD} ${LDFLAGS_AUTO} -o $@
+
 debug: clean
 	@$(MAKE) CFLAGS_EXTRA='${CFLAGS_EXTRA} ${CFLAGS_DEBUG}'
 
@@ -77,7 +80,7 @@ test:
 
 clean:
 	@echo cleaning
-	@rm -f vis vis-menu vis-${VERSION}.tar.gz *.gcov *.gcda *.gcno
+	@rm -f vis vis-menu vis-digraph vis-${VERSION}.tar.gz *.gcov *.gcda *.gcno
 
 dist: clean
 	@echo creating dist tarball
@@ -95,7 +98,7 @@ luadoc:
 luadoc-all:
 	@cd lua/doc && ldoc -a . && sed -e "s/RELEASE/${VERSION}/" -i index.html
 
-install: vis vis-menu
+install: vis vis-menu vis-digraph
 	@echo stripping executable
 	@${STRIP} vis
 	@echo installing executable files to ${DESTDIR}${PREFIX}/bin

lua/vis-std.lua

@@ -137,3 +137,27 @@ vis.events.subscribe(vis.events.WIN_STATUS, function(win)
 	local right = ' ' .. table.concat(right_parts, " « ") .. ' '
 	win:status(left, right);
 end)
+
+-- additional default keybindings
+
+vis:map(vis.modes.INSERT, "<C-k>", function(keys)
+	if #keys < 2 then
+		return -1 -- need more input
+	end
+	local file = io.popen(string.format("vis-digraph '%s' 2>&1", keys:gsub("'", "'\\''")))
+	local output = file:read('*all')
+	local success, msg, status = file:close()
+	if success then
+		if vis.mode == vis.modes.INSERT then
+			vis:insert(output)
+		elseif vis.mode == vis.modes.REPLACE then
+			vis:replace(output)
+		end
+	elseif msg == 'exit' then
+		if status == 2 then
+			return -1 -- prefix need more input
+		end
+		vis:info(output)
+	end
+	return #keys
+end, "Insert digraph")

man/vis-digraph.1

@@ -0,0 +1,68 @@
+.Dd January 27, 2017
+.Dt VIS-DIGRAPH 1
+.Os Vis VERSION
+.Sh NAME
+.Nm vis-digraph
+.Nd print Unicode character using mnemonics
+.
+.Sh SYNOPSIS
+.
+.Nm
+.Ar digraph ...
+.
+.Nm
+.Fl
+.
+.Sh DESCRIPTION
+.
+.Nm vis-digraph
+read a digraph from command line argument or standard input and print
+a corresponding Unicode character to standard output, encoded in current
+locale.
+.
+.Bl -tag -width 8
+.It Ar digraph
+A set of two (or more) characters that get replaced by a single Unicode
+character.
+.It Fl
+Read digraph from standard input.
+.El
+.Pp
+Without argument,
+.Nm
+displays all available digraphs along with a description.
+.
+.Sh ENVIRONMENT
+.
+.Bl -tag -width 8
+.
+.It Ev LC_CTYPE
+Locale definition, setting the encoding format of the Unicode character printed out.
+See
+.Xr locale 1
+for more information.
+.El
+.
+.Sh EXIT STATUS
+.
+.Bl -tag -width 4
+.It 0
+Digraph correctly read recognised and printed out.
+.It 1
+Digraph not recognised.
+.It 2
+Digraph is the beginning of an existing digraph, but does not correspond to a full digraph.
+.It 3
+An error occured and digraph could not be read or printed.
+.El
+.
+.Sh SEE ALSO
+.
+.Xr locale 1 ,
+.Xr vis 1
+.
+.Sh STANDARDS
+.
+.Nm
+follows the digraph format from
+.Lk http://tools.ietf.org/rfc/rfc1345.txt "RFC 1345"

man/vis.1

@@ -1290,6 +1290,7 @@ Spawn background process and pipe range to its standard input:
 .Sh SEE ALSO
 .Xr vis-clipboard 1 ,
 .Xr vis-complete 1 ,
+.Xr vis-digraph 1 ,
 .Xr vis-menu 1 ,
 .Xr vis-open 1 ,
 .Xr vi 1