clarified modules;

--- a/src/Tools/VSCode/extension/src/decorations.ts	Tue May 30 11:42:18 2017 +0200
+++ b/src/Tools/VSCode/extension/src/decorations.ts	Tue May 30 11:50:12 2017 +0200
@@ -4,8 +4,8 @@
 import * as vscode from 'vscode'
 import { Position, Range, MarkedString, DecorationOptions, DecorationRenderOptions,
   TextDocument, TextEditor, TextEditorDecorationType, ExtensionContext, Uri } from 'vscode'
-import { get_color } from './extension'
 import { Decoration } from './protocol'
+import * as library from './library'
 
 
 /* known decoration types */
@@ -81,31 +81,31 @@
   function background(color: string): TextEditorDecorationType
   {
     return decoration(
-      { light: { backgroundColor: get_color(color, true) },
-        dark: { backgroundColor: get_color(color, false) } })
+      { light: { backgroundColor: library.get_color(color, true) },
+        dark: { backgroundColor: library.get_color(color, false) } })
   }
 
   function text_color(color: string): TextEditorDecorationType
   {
     return decoration(
-      { light: { color: get_color(color, true) },
-        dark: { color: get_color(color, false) } })
+      { light: { color: library.get_color(color, true) },
+        dark: { color: library.get_color(color, false) } })
   }
 
   function text_overview_color(color: string): TextEditorDecorationType
   {
     return decoration(
       { overviewRulerLane: vscode.OverviewRulerLane.Right,
-        light: { overviewRulerColor: get_color(color, true) },
-        dark: { overviewRulerColor: get_color(color, false) } })
+        light: { overviewRulerColor: library.get_color(color, true) },
+        dark: { overviewRulerColor: library.get_color(color, false) } })
   }
 
   function bottom_border(width: string, style: string, color: string): TextEditorDecorationType
   {
     const border = `${width} none; border-bottom-style: ${style}; border-color: `
     return decoration(
-      { light: { border: border + get_color(color, true) },
-        dark: { border: border + get_color(color, false) } })
+      { light: { border: border + library.get_color(color, true) },
+        dark: { border: border + library.get_color(color, false) } })
   }
 
 

--- a/src/Tools/VSCode/extension/src/extension.ts	Tue May 30 11:42:18 2017 +0200
+++ b/src/Tools/VSCode/extension/src/extension.ts	Tue May 30 11:50:12 2017 +0200
@@ -4,6 +4,7 @@
 import * as path from 'path';
 import * as fs from 'fs';
 import * as os from 'os';
+import * as library from './library'
 import * as decorations from './decorations';
 import * as preview from './preview';
 import * as protocol from './protocol';
@@ -11,31 +12,15 @@
   from 'vscode-languageclient';
 
 
-/* Isabelle configuration */
-
-export function get_configuration<T>(name: string): T
-{
-  return vscode.workspace.getConfiguration("isabelle").get<T>(name)
-}
-
-export function get_color(color: string, light: boolean): string
-{
-  const config = color + (light ? "_light" : "_dark") + "_color"
-  return get_configuration<string>(config)
-}
-
-
-/* activate extension */
-
 let last_caret_update: protocol.Caret_Update = {}
 
 export function activate(context: vscode.ExtensionContext)
 {
   const is_windows = os.type().startsWith("Windows")
 
-  const isabelle_home = get_configuration<string>("home")
-  const isabelle_args = get_configuration<Array<string>>("args")
-  const cygwin_root = get_configuration<string>("cygwin_root")
+  const isabelle_home = library.get_configuration<string>("home")
+  const isabelle_args = library.get_configuration<Array<string>>("args")
+  const cygwin_root = library.get_configuration<string>("cygwin_root")
 
 
   /* server */

--- a/src/Tools/VSCode/extension/src/library.ts	Tue May 30 11:42:18 2017 +0200
+++ b/src/Tools/VSCode/extension/src/library.ts	Tue May 30 11:50:12 2017 +0200
@@ -1,7 +1,23 @@
 'use strict';
 
-import { ViewColumn, TextEditor } from 'vscode'
+import { ViewColumn, TextEditor, workspace } from 'vscode'
+
+
+/* Isabelle configuration */
 
+export function get_configuration<T>(name: string): T
+{
+  return workspace.getConfiguration("isabelle").get<T>(name)
+}
+
+export function get_color(color: string, light: boolean): string
+{
+  const config = color + (light ? "_light" : "_dark") + "_color"
+  return get_configuration<string>(config)
+}
+
+
+/* text editor column */
 
 export function other_column(active_editor: TextEditor | null): ViewColumn
 {