add completion provider

Author: krvajal

src/features/completion-provider.ts

@@ -0,0 +1,63 @@
+
+
+import { CancellationToken, TextDocument, Position, Hover } from "vscode";
+import * as fs from 'fs';
+import * as vscode from 'vscode';
+import { isPositionInString, intrinsics, FORTRAN_KEYWORDS } from "../lib/helper";
+
+
+export class FortranCompletionProvider implements vscode.CompletionItemProvider {
+
+    public provideCompletionItems(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken): Thenable<vscode.CompletionItem[]> {
+        return this.provideCompletionItemsInternal(document, position, token, vscode.workspace.getConfiguration('go'));
+    }
+    public provideCompletionItemsInternal(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken, config: vscode.WorkspaceConfiguration): Thenable<vscode.CompletionItem[]> {
+        return new Promise<vscode.CompletionItem[]>((resolve, reject) => {
+            let filename = document.fileName;
+            let lineText = document.lineAt(position.line).text;
+            let lineTillCurrentPosition = lineText.substr(0, position.character);
+            // nothing to complete
+            if (lineText.match(/^\s*\/\//)) {
+                return resolve([]);
+            }
+
+            let inString = isPositionInString(document, position);
+            if (!inString && lineTillCurrentPosition.endsWith('\"')) { // completing a string
+                return resolve([]);
+            }
+
+            // get current word
+            let wordAtPosition = document.getWordRangeAtPosition(position);
+            let currentWord = '';
+            if (wordAtPosition && wordAtPosition.start.character < position.character) {
+                let word = document.getText(wordAtPosition);
+                currentWord = word.substr(0, position.character - wordAtPosition.start.character);
+            }
+
+            if (currentWord.match(/^\d+$/)) { // starts with a number
+                return resolve([]);
+            }
+
+            let suggestions = [];
+
+            if (currentWord.length > 0) {
+                intrinsics.forEach(intrinsic => {
+                    if (intrinsic.startsWith(currentWord.toUpperCase())) {
+                        suggestions.push(new vscode.CompletionItem(intrinsic, vscode.CompletionItemKind.Method));
+                    }
+                });
+
+                // add keyword suggestions
+               FORTRAN_KEYWORDS.forEach(keyword => {
+                    if (keyword.startsWith(currentWord.toUpperCase())) {
+                        suggestions.push(new vscode.CompletionItem(keyword.toLowerCase(), vscode.CompletionItemKind.Keyword));
+                    }
+                });
+            }
+
+            return resolve(suggestions);
+
+        })
+
+    }
+}

src/lib/helper.ts

@@ -19,6 +19,8 @@ export const intrinsics = [
     "SYSTEM_CLOCK", "TAN", "TANH", "THIS_IMAGE", "TIME", "TIME8", "TINY", "TRAILZ", "TRANSFER", "TRANSPOSE", "TRIM", "TTYNAM", "UBOUND", "UCOBOUND", "UMASK", "UNLINK", "UNPACK", "VERIFY", "XOR"];
 
 
+export const FORTRAN_KEYWORDS = ["FUNCTION", "MODULE",  "SUBROUTINE", "CONTAINS", "USE","KIND", "DO", "IF", "ELIF","END", "IMPLICIT"];
+
 export const isIntrinsic = (keyword) => {
     return intrinsics.findIndex(intrinsic => intrinsic === keyword.toUpperCase()) !== -1;
 }
@@ -80,3 +82,15 @@ export const getIncludeParams =  (paths: string[]) => {
 }
 
 
+
+export function isPositionInString(document: vscode.TextDocument, position: vscode.Position): boolean {
+	let lineText = document.lineAt(position.line).text;
+	let lineTillCurrentPosition = lineText.substr(0, position.character);
+
+	// Count the number of double quotes in the line till current position. Ignore escaped double quotes
+	let doubleQuotesCnt = (lineTillCurrentPosition.match(/\"/g) || []).length;
+	let escapedDoubleQuotesCnt = (lineTillCurrentPosition.match(/\\\"/g) || []).length;
+
+	doubleQuotesCnt -= escapedDoubleQuotesCnt;
+	return doubleQuotesCnt % 2 === 1;
+}