Update parser

Implied nodes caused ambiguity when querying for context. Now every line
is considered, even blank lines, to make the process much easier.

package.json

@@ -46,7 +46,13 @@
 			{
 				"command": "mind-reader.selectTheme",
 				"title": "Select Theme"
+			},
+
+			{
+				"command": "mind-reader.runLineContext",
+				"title": "Run Line Context"
 			}
+
 		],
         "keybindings": [
             {

src/commands.ts

@@ -1,4 +1,5 @@
 import * as vscode from 'vscode';
+import * as pl from './pylex';
 
 /**
  * @type {Object} Command // Command to register with the VS Code Extension API
@@ -48,6 +49,11 @@ const commands: Command[] = [
     name: 'mind-reader.resetEditorScale',
     callback: resetEditorScale,
   },
+
+  {
+    name: 'mind-reader.runLineContext',
+    callback: runLineContext,
+  },
 ];
 
 // COMMAND CALLBACK IMPLEMENTATIONS
@@ -76,4 +82,57 @@ function resetEditorScale(): void {
   vscode.commands.executeCommand('workbench.action.zoomReset');
 }
 
+function runLineContext(): void {
+  let editor = vscode.window.activeTextEditor;
+  if (editor) {
+    // current text and line number
+    let editorText = editor.document.getText();
+    let line = editor.selection.active.line;
+
+    // get tab info settings
+    let size = parseInt(editor.options.tabSize as string);
+    let hard = !editor.options.insertSpaces;
+
+    // initialize parser
+    let parser = new pl.Parser(editorText, {size, hard});
+    parser.parse();
+
+    let context = parser.context(line);
+
+    // build text
+    let contentString = createContextString(context, line);
+    vscode.window.showInformationMessage(contentString);
+  } else {
+    vscode.window.showErrorMessage('No document currently active');
+  }
+}
+
+function createContextString(context: pl.LexNode[], line: number): string {
+    if (context.length < 1) {
+      throw new Error('Cannot create context string for empty context');
+    }
+
+    let contextString = 'Line ' + (line+1); // 1 based
+    if (context[0].token && context[0].token.attr) {
+      contextString += ': ' + context[0].token.type.toString() + ' ' + context[0].token.attr.toString();
+    }
+    for (let i = 1; i < context.length; i++) {
+      let node = context[i];
+      if (node.label === 'root') {
+        // root
+        contextString += ' in the Document Root';
+        continue;
+      }
+
+      if (node.token!.type != pl.PylexSymbol.EMPTY &&
+        node.token!.type != pl.PylexSymbol.INDENT) {
+        contextString += ' inside ' + node.token!.type.toString();
+        if (node.token!.attr) {
+          contextString += ' ' + node.token!.attr.toString();
+        }
+      }
+    }
+    return contextString;
+}
+
 export default commands;

src/pylex/index.ts

@@ -4,4 +4,4 @@ export {default as LineToken} from './token';
 export {default as Lexer} from './lexer';
 export {default as LexNode} from './node';
 export {TabInfo as TabInfo} from './token';
-
+export {Symbol as PylexSymbol} from './token';

src/pylex/lexer.ts

@@ -159,14 +159,15 @@ export default class Lexer {
       }
       // No rules matched
 
-      // Skip this line if it is whitespace, comment, or empty
+      // TODO: move to rules
       if (/^\s*(#.*)?$/.test(line)) {
-        this.pos++;
-        continue;
-      }
-
+        // "empty" line
+        token = new LineToken(Symbol.EMPTY, this.pos, 999999);
+      } else {
         // This is an INDENT token
         token = new LineToken(Symbol.INDENT, this.pos, indent);
+      }
+
       this._currToken = token;
       this.pos++;
       return this.currToken();

src/pylex/node.ts

@@ -2,6 +2,8 @@ import * as vscode from 'vscode';
 
 import LineToken from './token';
 
+/* TODO: make accessing children and parent less tedious */
+/* TODO: 'root.children()![i])' */
 /**
  * A node in a Parse tree.
  */

src/pylex/parser.ts

@@ -3,6 +3,7 @@ import * as vscode from 'vscode';
 import { EOFTOKEN, Symbol, TabInfo } from './token';
 import Lexer from './lexer';
 import LexNode from './node';
+/* TODO: update design doc */
 
 /**
  * A parse tree generator
@@ -71,8 +72,20 @@ export default class Parser {
         // go up 1 level of recursion at a time to unravel properly
         this.currIndent--;
         return children;
-      } else if (this.lexer.currToken().type === Symbol.INDENT) {
+      }
+
+      if (this.lexer.currToken().type === Symbol.INDENT ||
+          this.lexer.currToken().type === Symbol.EMPTY) {
+        const label = this.lexer.currToken().type;
         // regular code, advance and stay in same block
+        children.push(new LexNode(
+          label,
+          vscode.TreeItemCollapsibleState.None,
+          this.lexer.currToken(),
+          null,
+          parent)
+        );
+
         this.lexer.next();
         continue;
       } else {
@@ -105,29 +118,28 @@ export default class Parser {
    * @param `lineNumber` The line number to query context for.
    * @return An array of LexNodes for the root path containing `lineNumber`
    */
-  context(lineNumber: number): LexNode[] {
-    if (!this.root.children()) {
+  context(lineNumber: number, root?: LexNode): LexNode[] {
+    if (!root) {
+      root = this.root
+    }
+
+    // is this the target?
+    if (root.token && root.token!.linenr === lineNumber) {
+      // match
+      return root.rootPath();
+    }
+
+    if (root.children()) {
+      // recursive call
+      for (let i = 0; i < root.children()!.length; i++) {
+        let ctx = this.context(lineNumber, root.children()![i]);
+        if (ctx.length > 0) {
+          // a rootpath was returned
+          return ctx;
+        }
+      }
+    }
+    // no matches
     return [];
   }
-
-    // Returns the LexNode that is the parent
-    // of the queried line number
-    let find = (root: LexNode): LexNode | undefined => {
-      let prevChild: LexNode;
-      for (var child of root.children()!) {
-        if (lineNumber < child.token!.linenr) {
-          if (prevChild!.children()) {
-            return find(prevChild!);
-          } else {
-            return prevChild!;
-          }
-        } else {
-          prevChild = child;
-        }
-      }
-    };
-
-    let target = find(this.root);
-    return target!.rootPath();
-  }
 }

src/pylex/token.ts

@@ -17,6 +17,7 @@ export enum Symbol {
   FINALLY = "finally",
   WITH = "with",
   INDENT = "INDENT", // Indent token, default if not EOF, only contains indent information
+  EMPTY = "EMPTY", // empty line, used only to associate with the previous line
   EOF = "EOF"
 }