REPL: add variant option (#549)

* REPL: add variant option

* .

* Fix bug: yield new array (#40)

* fix bug: yield new array for array expression

* Add user friendly REPL message (#43)

* add user friendly REPL message

* Add randomized amb operator (#15)

Adds the ambR operator which functions similarly to amb
but makes choices randomly instead of sequentially.

Also adds landing page and library documentation for
the operator, and adds this operator into the specs.

* Add while loops (#39)

This PR adds support for while loops, including break,
continue and return statements in the loop body.

It also tweaks the scheduler so that stackoverflow errors
are captured and displayed to the user.

Co-authored-by: anubh-v <[email protected]>

* Clear the stack trace of any error created in REPL (#46)

* Add for loops (#41)

This PR adds support for for loops, including break,
continue and return statements in the loop body.
Co-authored-by: Anubhav <[email protected]>

* Add documentation for loops (#44)



Co-authored-by: anubh-v <[email protected]>

* Improve comments in non-det interpreter (#47)

* Remove unhelpful comment

* Fix spelling in comment

* allow only supported chapter and variant combinations

* format

Co-authored-by: martin-henz <[email protected]>
Co-authored-by: anubh-v <[email protected]>
Co-authored-by: Anubhav <[email protected]>

Author: 3 people

src/constants.ts

@@ -1,4 +1,5 @@
 import * as es from 'estree'
+import { SourceLanguage } from './types'
 
 export const CUT = 'cut' // cut operator for Source 4.3
 export const TRY_AGAIN = 'try again' // command for Source 4.3
@@ -19,3 +20,16 @@ export const JSSLANG_PROPERTIES = {
   maxExecTime: 1000,
   factorToIncreaseBy: 10
 }
+
+export const sourceLanguages: SourceLanguage[] = [
+  { chapter: 1, variant: 'default' },
+  { chapter: 1, variant: 'wasm' },
+  { chapter: 1, variant: 'lazy' },
+  { chapter: 2, variant: 'default' },
+  { chapter: 2, variant: 'lazy' },
+  { chapter: 3, variant: 'default' },
+  { chapter: 3, variant: 'concurrent' },
+  { chapter: 3, variant: 'non-det' },
+  { chapter: 4, variant: 'default' },
+  { chapter: 4, variant: 'gpu' }
+]

src/repl/repl.ts

@@ -4,6 +4,7 @@ import { inspect } from 'util'
 import { createContext, IOptions, parseError, runInContext } from '../index'
 import { Variant, ExecutionMethod } from '../types'
 import Closure from '../interpreter/closure'
+import { sourceLanguages } from '../constants'
 
 function startRepl(
   chapter = 1,
@@ -14,15 +15,15 @@ function startRepl(
   prelude = ''
 ) {
   // use defaults for everything
-  const context = createContext(chapter, undefined, undefined, undefined)
+  const context = createContext(chapter, variant, undefined, undefined)
   const options: Partial<IOptions> = {
     scheduler: 'preemptive',
     executionMethod,
     variant,
     useSubst
   }
   runInContext(prelude, context, options).then(preludeResult => {
-    if (preludeResult.status === 'finished') {
+    if (preludeResult.status === 'finished' || preludeResult.status === 'suspended-non-det') {
       console.dir(preludeResult.value, { depth: null })
       if (!useRepl) {
         return
@@ -32,7 +33,7 @@ function startRepl(
         {
           eval: (cmd, unusedContext, unusedFilename, callback) => {
             runInContext(cmd, context, options).then(obj => {
-              if (obj.status === 'finished') {
+              if (obj.status === 'finished' || obj.status === 'suspended-non-det') {
                 callback(null, obj.value)
               } else {
                 callback(new Error(parseError(context.errors)), undefined)
@@ -57,23 +58,46 @@ function startRepl(
   })
 }
 
+/**
+ * Returns true iff the given chapter and variant combination is supported.
+ */
+function validChapterVariant(chapter: any, variant: any) {
+  for (const lang of sourceLanguages) {
+    if (lang.chapter === chapter && lang.variant === variant) return true
+  }
+
+  return false
+}
+
 function main() {
   const opt = require('node-getopt')
     .create([
       ['c', 'chapter=CHAPTER', 'set the Source chapter number (i.e., 1-4)', '1'],
+      [
+        'v',
+        'variant=VARIANT',
+        'set the Source variant (i.e., default, lazy, non-det, concurrent, wasm, gpu)',
+        'default'
+      ],
       ['s', 'use-subst', 'use substitution'],
       ['h', 'help', 'display this help'],
       ['i', 'interpreter', 'use the interpreter for execution'],
-      ['l', 'lazy', 'use lazy evaluation'],
       ['e', 'eval', "don't show REPL, only display output of evaluation"]
     ])
     .bindHelp()
     .setHelp('Usage: js-slang [PROGRAM_STRING] [OPTION]\n\n[[OPTIONS]]')
     .parseSystem()
 
-  const executionMethod = opt.options.interpreter === true ? 'interpreter' : 'native'
-  const variant = opt.options.lazy === true ? 'lazy' : 'default'
+  const variant = opt.options.variant
   const chapter = parseInt(opt.options.chapter, 10)
+  const areValidChapterVariant: boolean = validChapterVariant(chapter, variant)
+  if (!areValidChapterVariant) {
+    throw new Error(
+      'The chapter and variant combination provided is unsupported. Use the -h option to view valid chapters and variants.'
+    )
+  }
+
+  const executionMethod = opt.options.interpreter === true ? 'interpreter' : 'native'
   const useSubst = opt.options.s
   const useRepl = !opt.options.e
   const prelude = opt.argv[0] ?? ''

src/types.ts

@@ -59,6 +59,11 @@ export interface Comment {
 export type ExecutionMethod = 'native' | 'interpreter' | 'auto'
 export type Variant = 'wasm' | 'lazy' | 'non-det' | 'concurrent' | 'gpu' | 'default' // this might replace EvaluationMethod
 
+export interface SourceLanguage {
+  chapter: number
+  variant: Variant
+}
+
 export interface Context<T = any> {
   /** The source version used */
   chapter: number