Ding/mark region in source 2

README.md

@@ -1,69 +1,71 @@
 # Source Programs
 
-This repo contains programs written in [Source](https://en.wikipedia.org/wiki/Source_(programming_language)), developed for [SICP JS](https://en.wikipedia.org/wiki/Structure_and_Interpretation_of_Computer_Programs,_JavaScript_Adaptation) and other educational projects. 
+This repo contains programs written in [Source](<https://en.wikipedia.org/wiki/Source_(programming_language)>), developed for [SICP JS](https://en.wikipedia.org/wiki/Structure_and_Interpretation_of_Computer_Programs,_JavaScript_Adaptation) and other educational projects.
 
 All programs in this repository are runnable in the [Source Academy playground](https://sourceacademy.nus.edu.sg/playground#chap=4): copy the program into the editor, choose "Source §4", and press "Run".
 
 ## Evaluators
 
 The evaluators in this section all follow the general style of SICP JS Chapter 4.
 
-* [`src/evaluators/source-0.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-0.js): evaluator for Source §0 (calculator language)
-* [`src/evaluators/source-0-pp.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-0-pp.js): evaluator for Source §0++ (calculator language plus conditionals, blocks and sequences)
-* [`src/evaluators/source-2.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-2.js): evaluator for Source §2, described in SICP JS 4.1
-* [`src/evaluators/source-2-lazy.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-2-lazy.js): lazy evaluator for Source §2, described in SICP JS 4.2
-* [`src/evaluators/source-2-non-det.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-2-non-det.js): evaluator for Source §2 with non-determinism, described in SICP JS 4.3
-* [`src/evaluators/typed-source.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/typed-source.js): evaluator for Typed Source (typed version of a Source §1 sublanguage)
+- [`src/evaluators/source-0.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-0.js): evaluator for Source §0 (calculator language)
+- [`src/evaluators/source-0-pp.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-0-pp.js): evaluator for Source §0++ (calculator language plus conditionals, blocks and sequences)
+- [`src/evaluators/source-2.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-2.js): evaluator for Source §2, described in SICP JS 4.1
+- [`src/evaluators/source-2-lazy.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-2-lazy.js): lazy evaluator for Source §2, described in SICP JS 4.2
+- [`src/evaluators/source-2-non-det.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/source-2-non-det.js): evaluator for Source §2 with non-determinism, described in SICP JS 4.3
+- [`src/evaluators/typed-source.js`](https://github.com/source-academy/source-programs/blob/master/src/evaluators/typed-source.js): evaluator for Typed Source (typed version of a Source §1 sublanguage)
 
 ## Steppers
 
 The steppers in this section implement a small-step semantics, following the substitution model of SICP JS Chapter 1 and 2.
 
-* [`src/steppers/source-0.js`](https://github.com/source-academy/source-programs/blob/master/src/steppers/source-0.js): stepper for Source §0
+- [`src/steppers/source-0.js`](https://github.com/source-academy/source-programs/blob/master/src/steppers/source-0.js): stepper for Source §0
 
 ## Type checkers
 
 The type checkers in this section follow a rule-based static semantics available in [doc/type-checking.pdf](https://github.com/source-academy/source-programs/blob/master/doc/type-checking.pdf).
 
-* [`src/type-checkers/source-0.js`](https://github.com/source-academy/source-programs/blob/master/): type checker for Source §0
-* [`src/type-checkers/typed-source.js`](https://github.com/source-academy/source-programs/blob/master/src/type-checkers/source-0.js): type checker for Typed Source, a typed version of a Source §1 sublanguage
+- [`src/type-checkers/source-0.js`](https://github.com/source-academy/source-programs/blob/master/): type checker for Source §0
+- [`src/type-checkers/typed-source.js`](https://github.com/source-academy/source-programs/blob/master/src/type-checkers/source-0.js): type checker for Typed Source, a typed version of a Source §1 sublanguage
 
 ## Virtual machines
 
 The virtual machines in this section are SECD-style and follow a description in [doc/virtual-machines.pdf](https://github.com/source-academy/source-programs/blob/master/doc/virtual-machines.pdf). Each virtual machine comes with a compiler, implemented in the same file.
 
-* [`src/virtual-machines/source-0m.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-0m.js): virtual machine for Source §0- (calculator language without division)
-* [`src/virtual-machines/source-0.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-0.js): virtual machine for Source §0 (calculator language)
-* [`src/virtual-machines/source-0p.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-0p.js): virtual machine for Source §0 (calculator language with conditionals)
-* [`src/virtual-machines/source-1.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-1.js): virtual machine for a Source §1 sublanguage (without memory management)
-* [`src/virtual-machines/source-1-with-copying-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-1-with-copying-gc.js): virtual machine for a Source §1 sublanguage with a Cheney-style stop-and-copy garbage collector
-* [`src/virtual-machines/register-machine-gcd.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/register-machine-gcd.js): register machine following SICP JS Section 5.2, using GCD example
-* [`src/virtual-machines/source-2.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-2.js): virtual machine for a Source §2 sublanguage (without memory management)
-* [`src/virtual-machines/source-2-with-copying-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-2-with-copying-gc.js): virtual machine for a Source §2 sublanguage with a Cheney-style stop-and-copy garbage collector
-* [`src/virtual-machines/source-2-with-ms-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-2-with-ms-gc.js): virtual machine for a Source §2 sublanguage with a Mark-and-Sweep-style garbage collector
+- [`src/virtual-machines/source-0m.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-0m.js): virtual machine for Source §0- (calculator language without division)
+- [`src/virtual-machines/source-0.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-0.js): virtual machine for Source §0 (calculator language)
+- [`src/virtual-machines/source-0p.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-0p.js): virtual machine for Source §0 (calculator language with conditionals)
+- [`src/virtual-machines/source-1.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-1.js): virtual machine for a Source §1 sublanguage (without memory management)
+- [`src/virtual-machines/source-1-with-copying-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-1-with-copying-gc.js): virtual machine for a Source §1 sublanguage with a Cheney-style stop-and-copy garbage collector
+- [`src/virtual-machines/source-1-with-mark-region-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-1-with-mark-region-gc.js): virtual machine for a Source §1 sublanguage with a Mark-Region garbage collector (2-tier granularity and overflow allocator)
+- [`src/virtual-machines/register-machine-gcd.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/register-machine-gcd.js): register machine following SICP JS Section 5.2, using GCD example
+- [`src/virtual-machines/source-2-with-copying-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-2-with-copying-gc.js): virtual machine for a Source §2 sublanguage with a Cheney-style stop-and-copy garbage collector
+- [`src/virtual-machines/source-2-with-ms-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-2-with-ms-gc.js): virtual machine for a Source §2 sublanguage with a Mark-and-Sweep-style garbage collector
+- [`src/virtual-machines/source-2-with-mark-region-gc.js`](https://github.com/source-academy/source-programs/blob/master/src/virtual-machines/source-2-with-mark-region-gc.js): virtual machine for a Source §1 sublanguage with a Mark-Region garbage collector (2-tier granularity and overflow allocator)
 
 ## Tool Demos
 
 (click to run; for actual sources, go to [`src/tool-demos/`](https://github.com/source-academy/source-programs/blob/master/src/tool-demos/))
 
-* [`src/tool-demos/stepper.js`](https://tinyurl.com/SICPJS-stepper): stepper tool (small-step semantics, based on substitution)
-* [`src/tool-demos/box-and-pointer-diagrams.js`](https://tinyurl.com/SICPJS-box-and-pointer): box-and-pointer diagram visualizer for pairs and lists (following SICP JS chapter 2)
-* [`src/tool-demos/environment-model.js`](https://tinyurl.com/SICPJS-env-diagram): environment model visualizer (following SICP JS chapter 3)
+- [`src/tool-demos/stepper.js`](https://tinyurl.com/SICPJS-stepper): stepper tool (small-step semantics, based on substitution)
+- [`src/tool-demos/box-and-pointer-diagrams.js`](https://tinyurl.com/SICPJS-box-and-pointer): box-and-pointer diagram visualizer for pairs and lists (following SICP JS chapter 2)
+- [`src/tool-demos/environment-model.js`](https://tinyurl.com/SICPJS-env-diagram): environment model visualizer (following SICP JS chapter 3)
 
 ## Module Demos
 
 (click to run; for actual sources, go to [`src/module-demos/`](https://github.com/source-academy/source-programs/blob/master/src/module-demos/))
 
-* [`src/module-demos/runes.js`](https://tinyurl.com/SICPJS-hearts): the "picture language" of SICP JS 2.2.4
-* [`src/module-demos/twist.js`](https://tinyurl.com/SICPJS-twist): some fun with the "picture language"
-* [`src/module-demos/curves.js`](https://tinyurl.com/SICPJS-circle): a "curves" library for drawing curves with functional programming
-* [`src/module-demos/times.js`](https://tinyurl.com/SICPJS-timestables): visual times tables using the "curves" library
-* [`src/module-demos/sounds.js`](https://tinyurl.com/SICPJS-siren): a "sounds" library for generating sounds and music, starting from their constituent sine waves
-* [`src/module-demos/bohemian.js`](https://tinyurl.com/SICPJS-rhapsody): Bohemian Rhapsody cover using the "sounds" library 
-* [`src/module-demos/pix-n-flix.js`](https://tinyurl.com/SICP-distortion): a library for image and video processing, based on the constituent pixels
+- [`src/module-demos/runes.js`](https://tinyurl.com/SICPJS-hearts): the "picture language" of SICP JS 2.2.4
+- [`src/module-demos/twist.js`](https://tinyurl.com/SICPJS-twist): some fun with the "picture language"
+- [`src/module-demos/curves.js`](https://tinyurl.com/SICPJS-circle): a "curves" library for drawing curves with functional programming
+- [`src/module-demos/times.js`](https://tinyurl.com/SICPJS-timestables): visual times tables using the "curves" library
+- [`src/module-demos/sounds.js`](https://tinyurl.com/SICPJS-siren): a "sounds" library for generating sounds and music, starting from their constituent sine waves
+- [`src/module-demos/bohemian.js`](https://tinyurl.com/SICPJS-rhapsody): Bohemian Rhapsody cover using the "sounds" library
+- [`src/module-demos/pix-n-flix.js`](https://tinyurl.com/SICP-distortion): a library for image and video processing, based on the constituent pixels
 
 ## Test framework
-* [`src/test/framework/main.js`](https://github.com/source-academy/source-programs/blob/master/src/test/framework/): test framework for Source programs, written in Source §4
+
+- [`src/test/framework/main.js`](https://github.com/source-academy/source-programs/blob/master/src/test/framework/): test framework for Source programs, written in Source §4
 
 # Testing
 
@@ -77,51 +79,50 @@ Only the tests written will be run.
 
 Each test case is appended to your Source, and then run with `js-slang` (using Source §4). The last line of the test case is a `//` comment that must contain the expected result. For example, a stepper test case may be:
 
-``` js
+```js
 parse_and_evaluate("! (1 === 1 && 2 > 3);");
 // true
 ```
 
 Before you can run the tests, you need to install `js-slang` by typing:
 
-``` sh
+```sh
 % yarn
 % yarn install
 ```
 
 Run all test cases by typing:
 
-``` sh
+```sh
 % yarn test
 ```
 
 For failure cases (where you program is to throw error, e.g. memory exhausted error for virtual machines), you can include the error message as per normal. The lastest JS-Slang already throws the error message explicitly, without letting the underlying TypeScript handling it. Hence, an error message
 
-``` sh
+```sh
 Line 2073: Error: memory exhausted despite garbage collection undefined
 ```
 
 can be written in the test file:
 
-``` js
+```js
 // Line 2073: Error: memory exhausted despite garbage collection undefined
 ```
 
 or
 
-``` js
+```js
 // Error: memory exhausted despite garbage collection undefined
 ```
 
 where only the part that starts from `Error:` will be compared. Line number is be ignored as it varies. If line number is needed for a particular reason, it can be appended to the back.
 
-
->Integration of the `test` script with `src/test/framework/` is pending a fix to the `--variant` parameter; any help appreciated.
+> Integration of the `test` script with `src/test/framework/` is pending a fix to the `--variant` parameter; any help appreciated.
 
 # License
 
 [![GPL 3][gpl3-image]][gpl3]
-All JavaScript programs in this repository are licensed under the 
+All JavaScript programs in this repository are licensed under the
 [GNU General Public License Version 3][gpl3].
 
 [gpl3]: https://www.gnu.org/licenses/gpl-3.0.en.html

src/virtual-machines/__tests__/source-2-with-mark-region-gc.gc_test1.js

@@ -0,0 +1,10 @@
+parse_and_compile_and_run(20, 21, 3,
+"\
+const z = 100000000000;\
+function foo(x) {\
+    return x + z;\
+}\
+foo(200000);\
+list(1,2,3,4);\
+");
+// 'result: heap node of type = pair, value = [1,[2,[3,[4,null]]]]'

src/virtual-machines/__tests__/source-2-with-mark-region-gc.gc_test2.js

@@ -0,0 +1,8 @@
+parse_and_compile_and_run(40, 30, 5, "                        \
+function remove_duplicates(lst) {                                             \
+    return is_null(lst)                                                \
+        ? null                                                          \
+        : accumulate((x, y) => pair(x, remove_all(x, y)), lst, lst);        \
+}                                                                             \
+remove_duplicates(list(1, 2, 1, 3, 4, 2, 1, 5)); ");
+// 'result: heap node of type = pair, value = [1,[2,[3,[4,[5,null]]]]]'

src/virtual-machines/__tests__/source-2-with-mark-region-gc.gc_test3.js

@@ -0,0 +1,9 @@
+parse_and_compile_and_run(20, 20, 10, "                                                       \
+function subset(lst) {                                           \
+    return is_null(lst)                             \
+        ? pair(null, null) \
+        : append(map(l => pair(head(lst), l), subset(tail(lst))), \
+                 subset(tail(lst))); \
+}                                                                \
+subset(enum_list(0, 2)); ");
+// 'result: heap node of type = pair, value = [[0,[1,[2,null]]],[[0,[1,null]],[[0,[2,null]],[[0,null],[[1,[2,null]],[[1,null],[[2,null],[null,null]]]]]]]]'