From 33a596ef3e0dbe879675baa289b3457f954a195a Mon Sep 17 00:00:00 2001
From: =?utf8?q?Alexis=20Laferri=C3=A8re?= <alexis.laf@xymus.net>
Date: Fri, 6 Mar 2015 23:21:55 -0500
Subject: [PATCH] misc/vim: add a function to show the doc of the entity under
 the cursor
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Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
---
 misc/README.md          |   12 ++++++++++
 misc/vim/plugin/nit.vim |   57 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+)

diff --git a/misc/README.md b/misc/README.md
index 181c047..1a7b97f 100644
--- a/misc/README.md
+++ b/misc/README.md
@@ -37,6 +37,7 @@ Ensure that `~/.vimrc` contains
  * Automatic indentation
  * Syntax checker (require [Syntastic][2]).
  * Autocomplete for whole projects using module importations
+ * Show documentation in preview window
 
   [2]: https://github.com/scrooloose/syntastic
 
@@ -93,3 +94,14 @@ will use general metadata in the plugin directory.
 
 The metadata files from nitpick are stored in `~/.vim/nit/`. This location can be customized with
 the environment variable `NIT_VIM_DIR`.
+
+## Documentation in preview window
+
+You can display the documentation for the entity under the cursor with `:call Nitdoc()`.
+It will use the same metadata files as the omnifunc and the preview window.
+You may want to map the function to a shortcut by adding the following code to `~/.vimrc`.
+
+~~~
+" Map displaying Nitdoc to Ctrl-D
+map <C-d> :call Nitdoc()<enter>
+~~~
diff --git a/misc/vim/plugin/nit.vim b/misc/vim/plugin/nit.vim
index d1e92ef..c9d54d0 100644
--- a/misc/vim/plugin/nit.vim
+++ b/misc/vim/plugin/nit.vim
@@ -253,6 +253,63 @@ fun NitOmnifunc(findstart, base)
 	endif
 endfun
 
+" Show doc for the entity under the cursor in the preview window
+fun Nitdoc()
+	" Word under cursor
+	let word = expand("<cword>")
+
+	" All possible docs (there may be more than one entity with the same name)
+	let docs = []
+
+	" Search in all metadata files
+	for file in ['modules', 'classes', 'properties']
+		let path = NitMetadataFile(file.'.txt')
+		if empty(path)
+			continue
+		endif
+
+		for line in readfile(path)
+			let words = split(line, '#====#', 1)
+			let name = get(words, 0, '')
+			if name =~ '^' . word
+				" It fits our word, get long doc
+				let desc = get(words,3,'')
+				let desc = join(split(desc, '#nnnn#', 1), "\n")
+				call add(docs, desc)
+			endif
+		endfor
+	endfor
+
+	" Found no doc, give up
+	if empty(docs) || !(join(docs, '') =~ '\w')
+		return
+	endif
+
+	" Open the preview window on a temp file
+	execute "silent pedit " . tempname()
+
+	" Change to preview window
+	wincmd P
+
+	" Show all found doc one after another
+	for doc in docs
+		if doc =~ '\w'
+			silent put = doc
+			silent put = ''
+		endif
+	endfor
+
+	" Set options
+	setlocal buftype=nofile
+	setlocal noswapfile
+	setlocal syntax=none
+	setlocal bufhidden=delete
+
+	" Change back to the source buffer
+	wincmd p
+	redraw!
+endfun
+
 " Activate the omnifunc on Nit files
 autocmd FileType nit set omnifunc=NitOmnifunc
 
-- 
1.7.9.5