Onward!

README.md

@@ -44,12 +44,13 @@ Matanuska can do the following:
 2. Define variables
 3. Check conditionals
 4. Run loops
-5. Edit files in a BASIC style REPL
+5. Define functions
+6. Edit files in a BASIC style REPL
 
 However, some important capabilities are still missing, including (but not limited to):
 
 1. System commands and shell jobs
-2. Functions
+2. Define closures
 3. Arrays and other higher level types
 4. Compiler level type assertions
 5. Multi-line instructions
@@ -58,9 +59,14 @@ For more information, check out the backlog...
 
 ### Prioritized Backlog
 
+- [ ] Implement `onward` in loops
+  - [x] Initial implementation
+  - [x] Fixture CLI tests
+  - [ ] Fixture/snapshot compiler tests
+  - [ ] Implement visiting `onward` inside conditionals
+  - [ ] Get fixture tests working
 - [ ] Date/Time/Duration/TZData functions
 - [ ] Closures
-- [ ] Implement `onward` in loops
 - [ ] Refactor command input
   - `Cmd` in AST references a list of Instructions, not a "command" as in ADR 024
     - Should probably just use a `Line`

compiler/base.ts

@@ -13,6 +13,7 @@ import { showChunk } from '../debug';
 import { errorType } from '../errors';
 import {
   AssertionError,
+  NotImplementedError,
   SyntaxError,
   ParseError,
   ParseWarning,
@@ -130,8 +131,23 @@ export function isRootBlock(block: Block): boolean {
 // relevant blocks are defined.
 let ElseBlock: any = null;
 let ElseIfBlock: any = null;
+let ForBlock: any = null;
+let WhileBlock: any = null;
+let RepeatBlock: any = null;
 
-class IfBlock extends Block {
+class ConditionalBlock extends Block {
+  visitOnwardInstr(onward: Onward): void {
+    const block = this.find(ForBlock, WhileBlock, RepeatBlock);
+    if (!block) {
+      this.mismatched(onward, 'onward');
+      return;
+    }
+
+    block.visitOnwardInstr(onward);
+  }
+}
+
+class IfBlock extends ConditionalBlock {
   kind = 'if';
 
   constructor(public elseJump: Short) {
@@ -157,7 +173,7 @@ class IfBlock extends Block {
   }
 }
 
-class _ElseBlock extends Block {
+class _ElseBlock extends ConditionalBlock {
   kind = 'else';
 
   constructor(public endJump: Short) {
@@ -167,7 +183,10 @@ class _ElseBlock extends Block {
   visitEndIfInstr(_endIf: EndIf): void {
     this.compiler.endIf(this.endJump);
     this.end();
+    this.unwind();
+  }
 
+  private unwind(): void {
     let block: any = this.previous;
     while (block instanceof ElseIfBlock) {
       block.compiler.endIf(block.endJump);
@@ -190,7 +209,10 @@ class _ElseIfBlock extends IfBlock {
   visitEndIfInstr(_endIf: EndIf): void {
     const endJump = this.compiler.beginElse(this.elseJump);
     this.compiler.endIf(endJump);
+    this.unwind();
+  }
 
+  private unwind(): void {
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     let block: any = this;
     while (block instanceof ElseIfBlock) {
@@ -201,15 +223,11 @@ class _ElseIfBlock extends IfBlock {
   }
 }
 
-// Update the references here
-ElseBlock = _ElseBlock;
-ElseIfBlock = _ElseIfBlock;
-
 //
-// For, while, and repeat/until
+// Looping blocks
 //
 
-class ForBlock extends Block {
+class _ForBlock extends Block {
   kind = 'for';
 
   constructor(
@@ -219,9 +237,8 @@ class ForBlock extends Block {
     super();
   }
 
-  // TODO
-  visitOnwardInstr(onward: Onward): void {
-    super.visitOnwardInstr(onward);
+  visitOnwardInstr(_onward: Onward): void {
+    this.compiler.continueFor(this.incrStart);
   }
 
   visitNextInstr(_next: Next): void {
@@ -230,7 +247,7 @@ class ForBlock extends Block {
   }
 }
 
-class WhileBlock extends Block {
+class _WhileBlock extends Block {
   kind = 'while';
 
   constructor(
@@ -240,9 +257,8 @@ class WhileBlock extends Block {
     super();
   }
 
-  // TODO
-  visitOnwardInstr(onward: Onward): void {
-    super.visitOnwardInstr(onward);
+  visitOnwardInstr(_onward: Onward): void {
+    this.compiler.continueWhile(this.loopStart);
   }
 
   visitEndWhileInstr(_endWhile: EndWhile): void {
@@ -251,24 +267,33 @@ class WhileBlock extends Block {
   }
 }
 
-class RepeatBlock extends Block {
+class _RepeatBlock extends Block {
   kind = 'repeat';
 
+  continues: Short[];
+
   constructor(public startJump: Short) {
     super();
+    this.continues = [];
   }
 
-  // TODO
-  visitOnwardInstr(onward: Onward): void {
-    super.visitOnwardInstr(onward);
+  visitOnwardInstr(_onward: Onward): void {
+    this.compiler.continueRepeat(this.continues);
   }
 
   visitUntilInstr(until: Until): void {
-    this.compiler.endRepeat(until, this.startJump);
+    this.compiler.endRepeat(until, this.startJump, this.continues);
     this.end();
   }
 }
 
+// Update the references here
+ElseBlock = _ElseBlock;
+ElseIfBlock = _ElseIfBlock;
+ForBlock = _ForBlock;
+WhileBlock = _WhileBlock;
+RepeatBlock = _RepeatBlock;
+
 //
 // Functions
 //
@@ -918,6 +943,10 @@ export class LineCompiler implements InstrVisitor<void>, ExprVisitor<void> {
     this.patchJump(exitJump);
   }
 
+  continueFor(incrStart: Short): void {
+    this.emitLoop(incrStart);
+  }
+
   visitWhileInstr(while_: While): void {
     const [loopStart, exitJump] = this.beginWhile(while_.condition);
     this.block.begin(while_, new WhileBlock(loopStart, exitJump));
@@ -943,6 +972,10 @@ export class LineCompiler implements InstrVisitor<void>, ExprVisitor<void> {
     this.patchJump(exitJump);
   }
 
+  continueWhile(loopStart: Short): void {
+    this.emitLoop(loopStart);
+  }
+
   visitRepeatInstr(repeat: Repeat): void {
     const loopStart = this.chunk.code.length;
     this.block.begin(repeat, new RepeatBlock(loopStart));
@@ -952,15 +985,32 @@ export class LineCompiler implements InstrVisitor<void>, ExprVisitor<void> {
     this.block.handle(until);
   }
 
-  endRepeat(until: Until, start: Short): void {
+  endRepeat(until: Until, start: Short, continues: Short[]): void {
+    // Continues jump to the bottom
+    for (const cont of continues) {
+      this.patchJump(cont);
+    }
+
+    // Check the condition
     until.condition.accept(this);
 
+    // Exit if false
     const exitJump = this.emitJump(OpCode.JumpIfFalse);
 
+    // Finnegan begin again
     this.emitByte(OpCode.Pop);
     this.emitLoop(start);
 
+    // Exit here
     this.patchJump(exitJump);
+    // Pop the conditional check
+    this.emitByte(OpCode.Pop);
+  }
+
+  continueRepeat(continues: Short[]): void {
+    // We'll jump to the conditional check later
+    const jump = this.emitJump(OpCode.Jump);
+    continues.push(jump);
   }
 
   visitOnwardInstr(onward: Onward): void {

compiler/block.ts

@@ -1,5 +1,9 @@
 import { OpCode } from '../bytecode/opcodes';
-import { AssertionError, RuntimeError } from '../exceptions';
+import {
+  AssertionError,
+  NotImplementedError,
+  RuntimeError,
+} from '../exceptions';
 import { RuntimeFault } from '../faults';
 import { formatter } from '../format';
 import {
@@ -103,6 +107,19 @@ export abstract class Block implements InstrVisitor<void> {
     this.compiler.block = this.parent;
   }
 
+  public find(...types: any[]): Block | null {
+    let block: Block | null = this;
+    while (true) {
+      if (block === null) {
+        return block;
+      }
+      if (types.some((t) => block instanceof t)) {
+        return block;
+      }
+      block = block.parent || null;
+    }
+  }
+
   public handle(instr: Instr): void {
     instr.accept(this);
   }

test/__snapshots__/cli.spec.ts.snap

@@ -117,3 +117,71 @@ exports[`examples > 011-datetime.bas 1`] = `
 ",
 }
 `;
+
+exports[`fixtures > 001-for-onward.bas 1`] = `
+{
+  "exitCode": 0,
+  "stderr": "",
+  "stdout": "1
+2
+3
+4
+5
+biggers
+biggers
+biggers
+biggers
+biggers
+",
+}
+`;
+
+exports[`fixtures > 002-while-onward.bas 1`] = `
+{
+  "exitCode": 70,
+  "stderr": "TypeError: Invalid operand for < on undef: integer
+  Value: 10
+  From: integer
+  To: invalid
+",
+  "stdout": "",
+}
+`;
+
+exports[`fixtures > 003-repeat-onward.bas 1`] = `
+{
+  "exitCode": 70,
+  "stderr": "=== RUNTIME FAULT ===
+
+--- Internal Stack Trace ---
+RuntimeFault: Cannot cast nil to unknown
+    at castFault (/Users/josh/code/jfhbrook/matanuska/value/cast.ts:29:11)
+    at castNil (/Users/josh/code/jfhbrook/matanuska/value/cast.ts:260:10)
+    at cast (/Users/josh/code/jfhbrook/matanuska/value/cast.ts:368:14)
+    at Module.add (/Users/josh/code/jfhbrook/matanuska/operations.ts:76:24)
+    at Runtime.<anonymous> (/Users/josh/code/jfhbrook/matanuska/runtime.ts:335:34)
+    at Generator.next (<anonymous>)
+    at asyncGeneratorStep (/Users/josh/code/jfhbrook/matanuska/runtime.ts:18:28)
+    at _next (/Users/josh/code/jfhbrook/matanuska/runtime.ts:36:17)
+    at /Users/josh/code/jfhbrook/matanuska/runtime.ts:41:13
+    at new Promise (<anonymous>)
+
+--- Versions ---
+Matanuska BASIC: v0.0.1
+swc: v1.7.26
+vite: v1.7.26
+Node.js: v25.2.1
+
+This is a bug in Matanuska BASIC. If you copy this entire message and post it
+to the issues tracker:
+
+    https://github.com/jfhbrook/matanuska/issues
+
+the developers will do their best to fix it - and more importantly, they will
+owe you a beer, coffee or beverage of your choice. 🍻
+
+
+",
+  "stdout": "",
+}
+`;

test/cli.spec.ts

@@ -3,22 +3,27 @@ import { basename } from 'node:path';
 import { describe, expect, test } from 'vitest';
 
 import { run } from './helpers/cli';
-import { EXAMPLES } from './helpers/files';
+import { EXAMPLES, FIXTURES } from './helpers/files';
 
-describe('examples', () => {
-  for (const p of Object.keys(EXAMPLES)) {
-    const name = basename(p);
-    switch (name) {
-      // TODO: Some scripts will need mocked input
-      default:
-        test(name, async () => {
-          const { exitCode, host } = await run([p], process.env);
-          expect({
-            exitCode,
-            stdout: host.stdout.output,
-            stderr: host.stderr.output,
-          }).toMatchSnapshot();
-        });
+function scriptsSuite(files: Record<string, string>): () => void {
+  return () => {
+    for (const p of Object.keys(files)) {
+      const name = basename(p);
+      switch (name) {
+        // TODO: Some scripts will need mocked input
+        default:
+          test(name, async () => {
+            const { exitCode, host } = await run([p], process.env);
+            expect({
+              exitCode,
+              stdout: host.stdout.output,
+              stderr: host.stderr.output,
+            }).toMatchSnapshot();
+          });
+      }
     }
-  }
-});
+  };
+}
+
+describe('examples', scriptsSuite(EXAMPLES));
+describe('fixtures', scriptsSuite(FIXTURES));