Independent scheme #165

TRK95 · 2025-08-10T16:04:17Z

This PR adds comprehensive Scheme language support to Source Academy, implementing a complete Scheme Chapter 1 interpreter with direct SCM AST parsing (bypassing JavaScript's ES AST) and full integration with the Source Academy conductor system.

Integration Details:

Feature Flag Configuration:
The Scheme language module is available at:

https://trk95.github.io/scm-slang-pages/dist/index.js
This URL can be used in Source Academy's feature flag system to enable/disable Scheme language support.

Key Features Implemented:

Core Language Features (Scheme Chapter 1):
Variable Definitions: (define x 10) and x → 10
Function Definitions: (define (add x y) (+ x y)) and (add 3 4) → 7
Lambda Expressions: (lambda (x y) (+ x y))
Conditional Statements: (if (> 5 3) "yes" "no") → "yes"
Basic Arithmetic: (+ 3 5), (- 10 3), (* 4 2), (/ 8 2)
Comparisons: (> 5 3), (< 3 5), (= 5 5), (>= 5 5), (<= 3 5)
Boolean Operations: (and #t #f), (or #t #f), (not #f)

Technical Implementation:

Direct SCM AST Parsing: Parses Scheme code directly into Scheme-specific AST, avoiding JavaScript ES AST conversion
CSE Machine: Complete Control-Stash-Environment machine implementation
UMD Module Format: Compatible with browser and Node.js environments
Conductor Integration: Full integration with Source Academy's conductor system
Environment Persistence: Variables and functions persist across evaluations
Error Handling: Comprehensive error reporting with line/column information

Architecture:

Independent Module: Self-contained implementation that can be loaded independently
Feature Flag Ready: Can be enabled/disabled via Source Academy's feature flag system
Extensible Design: Easy to add new Scheme features and chapters

- Add complete CSE machine implementation with SICP Chapter 1 support - Add Source Academy Conductor integration following py-slang pattern - Add complex numbers support (exceeds py-slang capabilities) - Add comprehensive test suite with 100% pass rate - Add UMD bundle build system for production deployment - Preserve original transpiler system unchanged

…ructor

…function definition parsing

…s first

…ode.js CI

coveralls · 2025-08-10T16:06:45Z

Pull Request Test Coverage Report for Build 17544530225

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

For more information on this, see Tracking coverage changes with pull request builds.
To avoid this issue with future PRs, see these Recommended CI Configurations.
For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

1 of 7 (14.29%) changed or added relevant lines in 1 file are covered.
13 unchanged lines in 1 file lost coverage.
Overall coverage increased (+2.4%) to 53.236%

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/transpiler/types/nodes/scheme-node-types.ts	1	7	14.29%

Files with Coverage Reduction	New Missed Lines	%
src/transpiler/types/nodes/scheme-node-types.ts	13	58.19%

Totals
Change from base Build 16762143650:	2.4%
Covered Lines:	1380
Relevant Lines:	2395

💛 - Coveralls

…STORE_ENV instruction to properly restore environment after function calls - Fix function parameter binding in CSE machine - Compound functions now work correctly (functions using other functions) - Linear recursion and iteration working properly

…o handle (list) as function call instead of list literal - Fix car/cdr to work with both lists and pairs - Fix pair? to recognize lists as pairs - Fix list? to recognize empty list () as list - Add length function for lists and pairs - Fix quote syntax to parse 'a 'b 'c as symbols

…ct formatting standards - Fix CI pipeline formatting check

Bumps [jest](https://github.com/jestjs/jest/tree/HEAD/packages/jest) from 30.0.4 to 30.0.5. - [Release notes](https://github.com/jestjs/jest/releases) - [Changelog](https://github.com/jestjs/jest/blob/main/CHANGELOG.md) - [Commits](https://github.com/jestjs/jest/commits/v30.0.5/packages/jest) --- updated-dependencies: - dependency-name: jest dependency-version: 30.0.5 dependency-type: direct:development update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [ts-jest](https://github.com/kulshekhar/ts-jest) from 29.4.0 to 29.4.1. - [Release notes](https://github.com/kulshekhar/ts-jest/releases) - [Changelog](https://github.com/kulshekhar/ts-jest/blob/main/CHANGELOG.md) - [Commits](kulshekhar/ts-jest@v29.4.0...v29.4.1) --- updated-dependencies: - dependency-name: ts-jest dependency-version: 29.4.1 dependency-type: direct:development update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

…ing to fix build

- Add complete CSE machine implementation with SICP Chapter 1 support - Add Source Academy Conductor integration following py-slang pattern - Add complex numbers support (exceeds py-slang capabilities) - Add comprehensive test suite with 100% pass rate - Add UMD bundle build system for production deployment - Preserve original transpiler system unchanged

…ructor

…function definition parsing

…s first

…ode.js CI

…STORE_ENV instruction to properly restore environment after function calls - Fix function parameter binding in CSE machine - Compound functions now work correctly (functions using other functions) - Linear recursion and iteration working properly

…o handle (list) as function call instead of list literal - Fix car/cdr to work with both lists and pairs - Fix pair? to recognize lists as pairs - Fix list? to recognize empty list () as list - Add length function for lists and pairs - Fix quote syntax to parse 'a 'b 'c as symbols

…ct formatting standards - Fix CI pipeline formatting check

…ing to fix build

…x stack

s-kybound

With the limitations of Source chapter 1 in mind, looks good to merge less a few nits:

the parsing of ( and [ in the simple parser - both brackets should be counted differently to avoid the valid parsing of examples like ( + 1 2 3 ]
it seems like the conductor version loses the scheme numeric tower - only reals and complex numbers are considered now, without integers and rational numbers of (effectively) endless precision
other minor nits detailed in the various review comments

s-kybound · 2025-09-08T11:07:48Z

package.json

+    "@types/jest": "^29.5.12",
    "@types/node": "^22.15.30",
    "@typescript-eslint/eslint-plugin": "^6.4.0",
-    "babel-jest": "^30.0.5",


a downgrade?

nit - please merge the latest set of packages, unless this is necessary

s-kybound · 2025-09-08T11:12:36Z

src/transpiler/types/nodes/scheme-node-types.ts

  }

+  /**
+   * A node that represents a Scheme complex number.


just curious because in scheme complexes are also considered part of the numeric tower - i intended the "NumericLiteral" class to emcompass all scheme number types - ints, rationals, irrationals and complexes.

was there any specific reason why complex literals are treated differently?

s-kybound · 2025-09-08T11:14:25Z

src/test/11-test-complete-flow.ts

for now this is fine. but was there a reason why a test framework like jest wasn't used here?

s-kybound · 2025-09-14T15:04:27Z

src/CSE-machine/complex.ts

@@ -0,0 +1,151 @@
+// Complex number implementation for Scheme


i'm curious as to why complex number logic is separated into its own file. will this affect the scheme numeric tower?

s-kybound · 2025-09-14T15:23:19Z

src/CSE-machine/interpreter.ts

+  stash: Stash
+): void {
+  if (isInstr(item)) {
+    console.log("DEBUG: Evaluating instruction:", item.instrType);


this logging will be captured in the console of the webpage. is this necessary?

s-kybound · 2025-09-14T15:28:07Z

src/CSE-machine/primitives.ts

+  "+": (...args: Value[]) => {
+    if (args.length === 0) return { type: "number", value: 0 };
+
+    // Check if all args are numeric (number or complex)


does this mean that integers (big integers) and rational numbers (of type a/b) are not supported in this PR? only javascript numbers (which are reals) and complex numbers?

s-kybound · 2025-09-14T15:29:46Z

src/CSE-machine/primitives.ts

+  "list?": (value: Value) => {
+    return {
+      type: "boolean",
+      value: value.type === "list" || value.type === "nil",


does this mean that a value of form pair(0, nil) will not be considered a list?

s-kybound · 2025-09-14T15:38:43Z

src/CSE-machine/runCSEMachine.ts

+    globalStepCount += 1;
+    const current = control.shift()!;
+
+    // Kiểm tra loại node bằng instanceof


For team readability, could we switch these comments to English? That way everyone can maintain this code more easily 😅

s-kybound · 2025-09-14T15:40:55Z

src/CSE-machine/simple-parser.ts

+  while (current < code.length) {
+    const char = code[current];
+
+    if (char === "(" || char === "[") {


does this mean that ( + 1 2 3 ] will parse as a single s-expr?

s-kybound · 2025-09-14T15:44:12Z

src/CSE-machine/stack.ts

+    return [...this.items];
+  }
+}
+//Checking


not sure if these debug comments will also pop up on the dev console

martin-henz · 2025-09-15T00:38:26Z

Thanks for the detailed review @s-kybound. @TRK95 : It seems that we have made tremendous progress with Scheme §1. Please take a close look at Kyriel's comments.

s-kybound · 2025-09-15T08:34:02Z

@martin-henz also seems that we are reducing the functionality of scheme at the moment, so i've moved the old repository to the kyriel/old branch so that later devs can restore parts of the scheme functionality back!

martin-henz · 2025-09-15T08:41:17Z

@martin-henz also seems that we are reducing the functionality of scheme at the moment, so i've moved the old repository to the kyriel/old branch so that later devs can restore parts of the scheme functionality back!

Hmm, that's one way. Or @TRK95 could fix the issues in this PR?

s-kybound · 2025-09-15T08:51:14Z

Hmm, that's one way. Or @TRK95 could fix the issues in this PR?

I think the issues listed in the PR should be dealt with here!

The parsing issues of ( and [ should be dealt with
The loss of scheme integers/rationals can be explicitly left as a TODO if there's no time, but it would be nice to reimplement them in this PR if possible

I left the old implementation as reference for future work, for example in restoring first-class continuations, or in reimplementing macros.

martin-henz · 2025-09-15T09:06:23Z

Hmm, that's one way. Or @TRK95 could fix the issues in this PR?

I think the issues listed in the PR should be dealt with here!

The parsing issues of ( and [ should be dealt with

The loss of scheme integers/rationals can be explicitly left as a TODO if there's no time, but it would be nice to reimplement them in this PR if possible

I left the old implementation as reference for future work, for example in restoring first-class continuations, or in reimplementing macros.

Noted. Let's make separate issues on macros and first-class continuations so that we know what needs to be done after this PR is merged.

TRK95 · 2025-09-16T07:39:31Z

Ok, I can fix the issues. I will notice both of you when I’m done Vào Th 2, 15 thg 9, 2025 lúc 16:06 Martin Henz ***@***.***> đã viết:

…

*martin-henz* left a comment (source-academy/scm-slang#165) <#165 (comment)> Hmm, that's one way. Or @TRK95 <https://github.com/TRK95> could fix the issues in this PR? I think the issues listed in the PR should be dealt with here! 1. The parsing issues of ( and [ should be dealt with 2. The loss of scheme integers/rationals can be explicitly left as a TODO if there's no time, but it would be nice to reimplement them in this PR if possible I left the old implementation as reference for future work, for example in restoring first-class continuations, or in reimplementing macros. Noted. Let's make separate issues on macros and first-class continuations so that we know what needs to be done after this PR is merged. — Reply to this email directly, view it on GitHub <#165 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AURBD4JWNHB7V2GR663O6TD3SZ6SJAVCNFSM6AAAAACDROESFOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTEOJRGE2TAOBXHA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

s-kybound · 2025-09-24T09:56:57Z

@TRK95 don't worry about the new issues, those are unrelated to the scope of the project, and are left here as documentation 😅

are there any updates regarding the changes ?

TRK95 added 12 commits August 9, 2025 06:23

rm remnant code

09ed1d1

chore: add dist/index.js to repository for CDN and browser use

1343254

Add GitHub Pages deployment workflow

c5e3a83

Add GitHub Pages landing page

4198709

Fix: Add HelloServiceMessage protocol handshake in RunnerPlugin const…

7a60363

…ructor

Fix scm-slang integration: UMD format, conductor initialization, and …

d94c4af

…function definition parsing

Remove package-lock.json to fix CI/CD - project uses Yarn

a12f62b

Fix GitHub Actions: Use yarn instead of npm for deploy-pages workflow

b277f97

Temporarily disable deploy-pages workflow - need to setup GitHub Page…

1aaf9a8

…s first

Remove deploy-pages workflow to follow py-slang pattern - only keep N…

2efa27b

…ode.js CI

Add dist/ to .gitignore and remove dist folder - follow py-slang pattern

b9cb59a

TRK95 and others added 17 commits August 11, 2025 03:56

Fix code formatting with Prettier - Ensure all files conform to proje…

7ce0ea1

…ct formatting standards - Fix CI pipeline formatting check

Add stepper functionality with lambda and user-defined function support

a4485eb

chore(SRI-NA): pin jest/ts-jest/typescript; relax service handler typ…

9870318

…ing to fix build

rm remnant code

5604c76

chore: add dist/index.js to repository for CDN and browser use

95d7467

Add GitHub Pages deployment workflow

9e58002

Add GitHub Pages landing page

e2ef903

Fix: Add HelloServiceMessage protocol handshake in RunnerPlugin const…

c0f3c5b

…ructor

Fix scm-slang integration: UMD format, conductor initialization, and …

75bf14f

…function definition parsing

Remove package-lock.json to fix CI/CD - project uses Yarn

25fbb7a

Fix GitHub Actions: Use yarn instead of npm for deploy-pages workflow

4b8fb47

Temporarily disable deploy-pages workflow - need to setup GitHub Page…

9215ecd

…s first

TRK95 added 11 commits September 8, 2025 14:59

Remove deploy-pages workflow to follow py-slang pattern - only keep N…

4e2a319

…ode.js CI

Add dist/ to .gitignore and remove dist folder - follow py-slang pattern

7ba244c

Fix code formatting with Prettier - Ensure all files conform to proje…

cea33f7

…ct formatting standards - Fix CI pipeline formatting check

Add stepper functionality with lambda and user-defined function support

d0b70d7

chore(SRI-NA): pin jest/ts-jest/typescript; relax service handler typ…

8d37b19

…ing to fix build

chore(SRI-NA): prepare rebase by committing lockfile+pkg resolution

3ad4131

chore(SRI-NA): include yarn install state

25be399

chore(SRI-NA): resolve package.json/yarn.lock conflicts; pin jest 29.…

1aa5abb

…x stack

chore: format code with prettier

b17e15f

s-kybound requested changes Sep 14, 2025

View reviewed changes

This was referenced Sep 22, 2025

Introduce continuations back into scm-slang #175

Open

Introduce macros back into scm-slang #176

Open

		@@ -0,0 +1,151 @@
		// Complex number implementation for Scheme

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Independent scheme #165

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Independent scheme #165

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TRK95 commented Aug 10, 2025

Integration Details:

Key Features Implemented:

Technical Implementation:

Architecture:

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