Preseve whitespace for non-opcode lines

Except for the intial indent to the
opcode tab stop, maintain existing
whitespace for non-opcode lines.

Author: fredsa

src/common/format-asm.ts

@@ -54,7 +54,7 @@ function buildFormattedLine(indented: boolean, label: string, opcode: string, op
     return result;
 }
 
-export function formatAsmLine(raw: string, lineNum: number, indentUnit: string, tabSize: number, asmTabStops: AsmTabStops): string {
+export function formatAsmLine(raw: string, lineNum: number, indentUnit: string, tabSize: number, asmTabStops: AsmTabStops, mnemonics?: Set<string>): string {
     const text = raw.trimEnd();
     if (text === '') return '';
 
@@ -77,6 +77,21 @@ export function formatAsmLine(raw: string, lineNum: number, indentUnit: string,
         [opcode, operand] = splitFirst(content);
     }
 
+    // If line does not contain a known opcode, preserve whitespace after iniital indent.
+    if (mnemonics && opcode && !mnemonics.has(opcode.toLowerCase())) {
+        const rest = text.substring(firstNonSpace);
+        if (indented) {
+            return padToColumn('', asmTabStops.opcodes, indentUnit, tabSize) + rest;
+        }
+        if (opcode) {
+            // Non-indented with label: fix indent between label and rest.
+            const afterLabel = label.length;
+            const opcodePos = afterLabel + text.substring(afterLabel).search(/\S/);
+            return label + padToColumn(label, asmTabStops.opcodes, indentUnit, tabSize).substring(label.length) + text.substring(opcodePos);
+        }
+        return text;
+    }
+
     const newText = buildFormattedLine(indented, label, opcode, operand, comment, indentUnit, tabSize, asmTabStops);
     if (newText.replace(/\s/g, '') !== text.replace(/\s/g, '')) {
         console.warn(`format: skipping line ${lineNum}, mangles non-whitespace characters\n- before: ${JSON.stringify(text)}\n- after:  ${JSON.stringify(newText)}`);
@@ -85,10 +100,10 @@ export function formatAsmLine(raw: string, lineNum: number, indentUnit: string,
     return newText;
 }
 
-export function formatText(text: string, tabSize: number, asmTabStops: AsmTabStops): string {
+export function formatText(text: string, tabSize: number, asmTabStops: AsmTabStops, mnemonics?: Set<string>): string {
     if (!asmTabStops) return text;
     const indent = ' '.repeat(tabSize);
     const lines = text.split('\n');
-    const formatted = lines.map((line, i) => formatAsmLine(line, i + 1, indent, tabSize, asmTabStops));
+    const formatted = lines.map((line, i) => formatAsmLine(line, i + 1, indent, tabSize, asmTabStops, mnemonics));
     return formatted.join('\n');
 }

src/common/tabdetect.ts

@@ -43,7 +43,7 @@ const MNEMONICS_6502 = new Set([...opcodes6502].map(s => s.toLowerCase()));
 const MNEMONICS_6809 = new Set([...opcodes6809].map(s => s.toLowerCase()));
 const MNEMONICS_Z80 = new Set([...opcodesZ80].map(s => s.toLowerCase()));
 
-const mnemonicsByMode: Record<string, Set<string>> = {
+export const mnemonicsByMode: Record<string, Set<string>> = {
   '6502': MNEMONICS_6502,
   '6809': MNEMONICS_6809,
   'z80': MNEMONICS_Z80,

src/ide/format.ts

@@ -4,7 +4,7 @@ import { EditorView } from "@codemirror/view";
 import { formatAsmLine } from "../common/format-asm";
 import { tabStopsFacet } from "./settings";
 
-export function formatDocument(view: EditorView, isAsm: boolean) {
+export function formatDocument(view: EditorView, isAsm: boolean, mnemonics?: Set<string>) {
     let state = view.state;
     const changeSets: ChangeSet[] = [];
 
@@ -72,7 +72,7 @@ export function formatDocument(view: EditorView, isAsm: boolean) {
             for (let i = 1; i <= state.doc.lines; i++) {
                 if (!isTargetLine(i)) continue;
                 const line = state.doc.line(i);
-                const formatted = formatAsmLine(line.text, i, indent, tabSize, stops);
+                const formatted = formatAsmLine(line.text, i, indent, tabSize, stops, mnemonics);
                 if (formatted !== line.text) {
                     specs.push({ from: line.from, to: line.to, insert: formatted });
                 }

src/ide/views/editors.ts

@@ -23,6 +23,7 @@ import { mbo } from "../../themes/mbo";
 import { formatDocument } from "../format";
 import { loadSettings, registerEditor, settingsExtensions } from "../settings";
 import { clearBreakpoint, current_project, isAsmMode, lastDebugState, platform, runToPC } from "../ui";
+import { mnemonicsByMode } from "../../common/tabdetect";
 import { createAssetHeaderPlugin } from "./assetdecorations";
 import { ProjectView } from "./baseviews";
 import { createTextTransformFilterEffect, textTransformFilterCompartment } from "./filters";
@@ -92,6 +93,7 @@ export class SourceEditor implements ProjectView {
   newEditor(parent: HTMLElement, text: string, includesAsm?: boolean) {
     var modedef = MODEDEFS[this.mode] || MODEDEFS.default;
     var isAsm = isAsmMode(this.mode);
+    var mnemonics = mnemonicsByMode[this.mode];
     var lineWrap = !!modedef.lineWrap;
     var theme = modedef.theme || MODEDEFS.default.theme;
 
@@ -142,7 +144,7 @@ export class SourceEditor implements ProjectView {
           keydown(event, view) {
             if (event.shiftKey && event.altKey && event.code === 'KeyF') {
               event.preventDefault();
-              formatDocument(view, isAsm);
+              formatDocument(view, isAsm, mnemonics);
             }
           }
         }),