Stream: allow edge attributes, autoclose nodes

lib/classes/GraphStream.ts

@@ -22,7 +22,11 @@ interface Stringable {
 
 export class GraphStream extends Transform {
   private _path: string[] = [];
-  private _state: GraphStreamCommand | '' = '';
+  private _state: (GraphStreamCommand | '')[] = [
+    '',
+    ''
+  ];
+
   private _directional = false;
 
   public get path (): string {
@@ -33,6 +37,16 @@ export class GraphStream extends Transform {
     return '  '.repeat (this._path.length);
   }
 
+  private finish_node ():void {
+    if (
+      [
+        'ce',
+        'cn'
+      ].includes (this._state[1])
+    )
+      this.push ('\n');
+  }
+
   private expect_state (instr: GraphStreamCommand): void {
     const states: (GraphStreamCommand|'')[] = [];
     if ([
@@ -47,24 +61,21 @@ export class GraphStream extends Transform {
       'csg',
       'ce'
     ].includes (instr))
-      states.push ('en', 'at', 'eg', 'cug', 'cdg', 'csg', 'ce');
+      states.push ('at', 'eg', 'cug', 'cdg', 'csg', 'ce', 'cn');
 
     switch (instr) {
-      case 'en':
-        states.push ('cn', 'at');
-        break;
       case 'at':
-        states.push ('cn', 'cug', 'cdg', 'csg');
+        states.push ('cn', 'cug', 'cdg', 'csg', 'ce');
         break;
       default:
         break;
     }
-    if (!states.includes (this._state)) {
+    if (!states.includes (this._state[1])) {
       throw new Error (`invalid state to execute command ${
         translate_command (instr)}
   expected: ${states.map ((s) => translate_command (s))
     .join (', ')}
-  actual: ${translate_command (this._state)}`);
+  actual: ${translate_command (this._state[1])}`);
     }
   }
 
@@ -89,24 +100,27 @@ export class GraphStream extends Transform {
         this._directional = true;
         break;
       case 'csg': // create subgraph
+        this.finish_node ();
         this.push (
           `${this.level}subgraph cluster_${this.path}_${instr.args[0]} {\n`
         );
         this._path.push (instr.args[0]);
         break;
       case 'eg': // end graph
+        this.finish_node ();
         this._path.pop ();
         this.push (`${this.level}}\n\n`);
         break;
       case 'cn': // create node
+        this.finish_node ();
         this.push (`${this.level}${this.path}_${instr.args[0]}`);
         break;
-      case 'en': // end node
-        this.push ('\n');
-        break;
       case 'at': // add attributes
-        if (this._state === 'cn') {
-          this.push (` [${instr.args.join (', ')}]`);
+        if ([
+          'cn',
+          'ce'
+        ].includes (this._state[1])) {
+          this.push (` [${instr.args.join (', ')}]\n`);
         }
         else {
           this.push (`${this.level}${
@@ -116,14 +130,16 @@ export class GraphStream extends Transform {
         }
         break;
       case 'ce':
+        this.finish_node ();
         this.push (`${this.level}${
           instr.args[0]
-        } -${this._directional ? '>' : '-'} ${instr.args[1]}\n`);
+        } -${this._directional ? '>' : '-'} ${instr.args[1]}`);
         break;
       default:
         break;
     }
-    this._state = instr.type;
+    this._state.push (instr.type);
+    this._state.shift ();
     callback ();
   }
 
@@ -139,8 +155,11 @@ export class GraphStream extends Transform {
     return `${this.path}_${node_name}`;
   }
 
+  /**
+   * @deprecated calling this method is not needed anymore
+   */
   public end_node (): void {
-    this.write ({ type: 'en', args: [] });
+    // this.write ({ type: 'en', args: [] });
   }
 
   public create_graph (name: string, type: 'u'|'d'|'s' = 's'): void {