Improve return values

app/javascript/interpreter/error.ts

@@ -117,6 +117,7 @@ export type RuntimeErrorType =
   | 'UnexpectedReturnOutsideOfFunction'
   | 'ExpectedFunctionNotFound'
   | 'ExpectedFunctionHasWrongArguments'
+  | 'InvalidNestedFunction'
 
 export type StaticErrorType =
   | DisabledLanguageFeatureErrorType

app/javascript/interpreter/expression.ts

@@ -50,14 +50,15 @@ export class CallExpression extends Expression {
   }
 
   public description(
-    result: Partial<'value' | EvaluationResultCallExpression>
+    result: EvaluationResultCallExpression,
+    includeReturnValue = true
   ): string {
     const argsDescription = '()'
-    return `<code>${
-      this.callee.name.lexeme
-    }${argsDescription}</code> (which returned <code>${formatLiteral(
-      result.value
-    )}</code>)`
+    let desc = `<code>${this.callee.name.lexeme}${argsDescription}</code>`
+    if (includeReturnValue) {
+      desc += ` (which returned <code>${formatLiteral(result.value)}</code>)`
+    }
+    return desc
   }
 }
 

app/javascript/interpreter/frames.ts

@@ -23,6 +23,7 @@ import {
   SetVariableStatement,
   Statement,
   ChangeVariableStatement,
+  ReturnStatement,
 } from './statement'
 
 export type FrameType = 'ERROR' | 'REPEAT' | 'EXPRESSION'
@@ -225,8 +226,11 @@ function describeIfStatement(frame: FrameWithResult) {
   return output
 }
 function describeReturnStatement(frame: FrameWithResult) {
-  let output = `<p>This returned the value of <code>${frame.result.value.name}</code>, which in this case is <code>${frame.result.value.value}</code>.</p>`
-  return output
+  const context = frame.context as ReturnStatement
+  if (context === undefined) {
+    return ''
+  }
+  return context.description(frame.result)
 }
 function describeCallExpression(
   frame: FrameWithResult,

app/javascript/interpreter/locales/en/translation.json

@@ -14,7 +14,7 @@
       "MissingDoubleQuoteToTerminateString": "Did you forget to add end quote? Maybe you meant to write:\n\n```\"{{string}}\"```",
       "MissingEndAfterBlock": "Are you missing an `end` to finish the {{type}} body?",
       "MissingEndOfLine": "We didn't expect `{{current}}` to appear on this line after the `{{previous}}`. {{suggestion}}",
-      "MissingExpression": "Expect expression.",
+      "MissingExpression": "Jiki doesn't know what this means.",
       "MissingFieldNameOrIndexAfterLeftBracket": "Expect field name or index after '['.",
       "InvalidFunctionName": "Jiki couldn't work out what function you wanted to use here.",
       "MissingFunctionName": "Did you forget to give your function a name?",
@@ -55,7 +55,8 @@
       "UnexpectedSpaceInIdentifier": "Did you accidently put a space in the middle of a variable name?",
       "UnexpectedVariableExpressionAfterIf": "Did you forget to compare to things? In JikiScript the comparison (`is`, `==`, `>`, etc are always required).",
       "UnexpectedVariableExpressionAfterIfWithPotentialTypo": "We were expecting some sort of comparison here. Did you mean to type `{{potential}}` instead of `{{actual}}`?",
-      "UnexpectedEqualsForEquality": "To say \"equals\" in JikiScript, we use two equals signs (`==`). Did you forget one?"
+      "UnexpectedEqualsForEquality": "To say \"equals\" in JikiScript, we use two equals signs (`==`). Did you forget one?",
+      "InvalidNestedFunction": "You can't create a function within a function. Did you mean to create a function outside of this one?"
     },
     "semantic": {
       "CannotAssignToConstant": "Cannot re-assign value of constant.",

app/javascript/interpreter/locales/system/translation.json

@@ -96,7 +96,8 @@
       "VariableNotDeclared": "VariableNotDeclared: name: {{name}}",
       "ExpectedFunctionHasWrongArguments": "ExpectedFunctionHasWrongArguments: name: {{name}}",
       "ExpectedFunctionNotFound": "ExpectedFunctionNotFound: name: {{name}}",
-      "VariableNotAccessibleInFunction": "VariableNotAccessibleInFunction: name: {{name}}"
+      "VariableNotAccessibleInFunction": "VariableNotAccessibleInFunction: name: {{name}}",
+      "InvalidNestedFunction": "InvalidNestedFunction"
     },
     "disabledLanguageFeature": {
       "ExcludeListViolation": "ExcludeListViolation: tokenType: {{tokenType}}",

app/javascript/interpreter/parser.ts

@@ -167,7 +167,7 @@ export class Parser {
     if (this.match('REPEAT_FOREVER')) return this.repeatForeverStatement()
     if (this.match('REPEAT_UNTIL_GAME_OVER'))
       return this.repeatUntilGameOverStatement()
-    if (this.match('WHILE')) return this.whileStatement()
+    // if (this.match('WHILE')) return this.whileStatement()
     if (this.match('FOREACH')) return this.foreachStatement()
     if (this.match('DO')) return this.blockStatement('do')
 
@@ -753,6 +753,9 @@ export class Parser {
       )
     }
 
+    if (this.peek().type == 'FUNCTION') {
+      this.error('InvalidNestedFunction', this.peek().location)
+    }
     this.error('MissingExpression', this.peek().location)
   }
 

app/javascript/interpreter/statement.ts

@@ -1,9 +1,10 @@
 import {
   EvaluationResult,
   EvaluationResultChangeVariableStatement,
+  EvaluationResultReturnStatement,
   EvaluationResultSetVariableStatement,
 } from './evaluation-result'
-import { Expression } from './expression'
+import { Expression, LiteralExpression } from './expression'
 import { SomethingWithLocation } from './interpreter'
 import { Location } from './location'
 import type { Token } from './token'
@@ -149,6 +150,18 @@ export class ReturnStatement extends Statement {
   ) {
     super('ReturnStatement')
   }
+  public description(result: EvaluationResultReturnStatement) {
+    if (result.value == undefined) {
+      return `<p>This exited the function.</p>`
+    }
+    if (result.value.type == 'VariableLookupExpression') {
+      return `<p>This returned the value of <code>${result.value.name}</code>, which in this case is <code>${result.value.value}</code>.</p>`
+    }
+    // if(result.value.type == "LiteralExpression") {
+    else {
+      return `<p>This returned <code>${result.value.value}</code>.</p>`
+    }
+  }
 }
 
 export class ForeachStatement extends Statement {

app/javascript/interpreter/token.ts

@@ -57,7 +57,7 @@ export type TokenType =
   | 'TO'
   | 'TIMES'
   | 'TRUE'
-  | 'WHILE'
+  // | 'WHILE'
   | 'WITH'
 
   // Grouping tokens

test/javascript/interpreter/parser.test.ts

@@ -719,7 +719,7 @@ describe('repeat', () => {
 })
 
 describe('while', () => {
-  test('with single statement', () => {
+  test.skip('with single statement', () => {
     const stmts = parse(`
       while something is true do
         set x to 1

test/javascript/interpreter/statement_descriptions.test.ts → test/javascript/interpreter/statementDescriptions.test.ts

@@ -77,7 +77,6 @@ describe('IfStatement', () => {
           set name to "Jeremy"
         end
       `)
-      console.log(error)
       const actual = describeFrame(frames[0], [])
       expect(actual).toBe(
         `<p>This checked whether <code>true</code> was equal to <code>true</code></p>\n<p>The result was <code>true</code>.</p>`
@@ -89,7 +88,6 @@ describe('IfStatement', () => {
           set name to "Jeremy"
         end
       `)
-      console.log(error)
       const actual = describeFrame(frames[0], [])
       expect(actual).toBe(
         `<p>This checked whether both of these were true:</p><ul><li><code>true</code> was equal to <code>true</code></li><li><code>true</code> was equal to <code>true</code></li></ul><p></p>\n<p>The result was <code>true</code>.</p>`
@@ -104,7 +102,6 @@ describe('IfStatement', () => {
       `,
         { externalFunctions: [getTrueFunction] }
       )
-      console.log(frames[0])
       const actual = describeFrame(frames[0], [])
       expect(actual).toBe(
         `<p>This checked whether <code>get_true()</code> (which returned <code>true</code>) was equal to <code>true</code></p>\n<p>The result was <code>true</code>.</p>`
@@ -149,11 +146,59 @@ describe('IfStatement', () => {
       `,
         { externalFunctions: [getTrueFunction, getFalseFunction] }
       )
-      console.log(frames[0])
       const actual = describeFrame(frames[0], [])
       expect(actual).toBe(
         `<p>This checked whether both of these were true:</p><ul><li><code>get_true()</code> (which returned <code>true</code>) was equal to <code>get_true()</code> (which returned <code>true</code>)</li><li><code>get_false()</code> (which returned <code>false</code>) was equal to <code>get_false()</code> (which returned <code>false</code>)</li></ul><p></p>\n<p>The result was <code>true</code>.</p>`
       )
     })
   })
 })
+
+describe('ReturnStatement', () => {
+  test('no value', () => {
+    const { frames } = interpret(`
+      function get_name do
+        return
+      end
+      get_name()
+    `)
+    const actual = describeFrame(frames[0], [])
+    expect(actual).toBe('<p>This exited the function.</p>')
+  })
+  test('variable', () => {
+    const { frames } = interpret(`
+      function get_name do
+        set x to 1
+        return x
+      end
+      get_name()
+    `)
+    const actual = describeFrame(frames[1], [])
+    expect(actual).toBe(
+      '<p>This returned the value of <code>x</code>, which in this case is <code>1</code>.</p>'
+    )
+  })
+  test('complex option', () => {
+    const { frames } = interpret(`
+      function get_3 do
+        return 3
+      end
+      function get_name do
+        return get_3()
+      end
+      get_name()
+    `)
+    const actual = describeFrame(frames[1], [])
+    expect(actual).toBe('<p>This returned <code>3</code>.</p>')
+  })
+  test('literal', () => {
+    const { frames } = interpret(`
+      function get_name do
+        return 1
+      end
+      get_name()
+    `)
+    const actual = describeFrame(frames[0], [])
+    expect(actual).toBe('<p>This returned <code>1</code>.</p>')
+  })
+})

test/javascript/interpreter/syntaxErrors.test.ts

@@ -283,7 +283,7 @@ describe('syntax errors', () => {
       ).toThrow('MissingDoToStartBlock: type: repeat')
     })
 
-    test('while', () => {
+    test.skip('while', () => {
       expect(() =>
         parse(`
         while x equals 1
@@ -330,7 +330,7 @@ describe('syntax errors', () => {
       ).toThrow('MissingEndAfterBlock: type: repeat')
     })
 
-    test('while', () => {
+    test.skip('while', () => {
       expect(() =>
         parse(`
         while x equals 1 do
@@ -490,4 +490,16 @@ describe('syntax errors', () => {
       'MissingRightParenthesisAfterFunctionCall: function: move'
     )
   })
+
+  test('InvalidNestedFunction', () => {
+    expect(() =>
+      parse(`
+        function outer do
+          function inner do
+            return 1
+          end
+        end
+      `)
+    ).toThrow('InvalidNestedFunction')
+  })
 })