branching

src/interpreter/builtins.ts

@@ -28,6 +28,117 @@ const addUnaryIntegerOperationsTo = (env: Environment) => {
   return env;
 };
 
+const addNumberComparisonOperationsTo = (env: Environment) => {
+  const comparisonOperationsSignatures: DenotableFunctionSignature[] = [
+    {
+      arguments: [
+        ['real', 'int'],
+        ['real', 'int'],
+      ],
+      return: 'bool',
+    },
+  ];
+
+  for (const { name, fn } of [
+    { name: '<=', fn: (a: number, b: number) => (a <= b ? 1 : 0) },
+    { name: '<', fn: (a: number, b: number) => (a < b ? 1 : 0) },
+    { name: '>', fn: (a: number, b: number) => (a > b ? 1 : 0) },
+    { name: '>=', fn: (a: number, b: number) => (a >= b ? 1 : 0) },
+  ]) {
+    env.set(name, {
+      type: 'function',
+      value: {
+        signatures: comparisonOperationsSignatures,
+        body: ({ value: a }: Denotable, { value: b }: Denotable) =>
+          fn(a as number, b as number),
+      },
+    });
+  }
+
+  return env;
+};
+
+const addEqualityOperationsTo = (env: Environment) => {
+  const equalityOperationSignatures: DenotableFunctionSignature[] = [
+    {
+      arguments: ['int', 'int'],
+      return: 'bool',
+    },
+    {
+      arguments: ['real', 'real'],
+      return: 'bool',
+    },
+    {
+      arguments: ['bool', 'bool'],
+      return: 'bool',
+    },
+    {
+      arguments: ['string', 'string'],
+      return: 'bool',
+    },
+  ];
+
+  for (const { name, fn } of [
+    {
+      name: '==',
+      fn: (a: number | string, b: number | string) => (a === b ? 1 : 0),
+    },
+    {
+      name: '!=',
+      fn: (a: number | string, b: number | string) => (a !== b ? 1 : 0),
+    },
+  ]) {
+    env.set(name, {
+      type: 'function',
+      value: {
+        signatures: equalityOperationSignatures,
+        body: ({ value: a }: Denotable, { value: b }: Denotable) =>
+          fn(a as number | string, b as number | string),
+      },
+    });
+  }
+
+  return env;
+};
+
+const addBooleanAlgebraOperationsTo = (env: Environment) => {
+  const binaryBooleanOps: DenotableFunctionSignature[] = [
+    {
+      arguments: ['bool', 'bool'],
+      return: 'bool',
+    },
+  ];
+
+  for (const { name, fn } of [
+    { name: '||', fn: (a: number, b: number) => (a === 1 || b === 1 ? 1 : 0) },
+    { name: '&&', fn: (a: number, b: number) => (a === 1 && b === 1 ? 1 : 0) },
+  ]) {
+    env.set(name, {
+      type: 'function',
+      value: {
+        signatures: binaryBooleanOps,
+        body: ({ value: a }: Denotable, { value: b }: Denotable) =>
+          fn(a as number, b as number),
+      },
+    });
+  }
+
+  env.set('!', {
+    type: 'function',
+    value: {
+      signatures: [
+        {
+          arguments: ['bool'],
+          return: 'bool',
+        },
+      ],
+      body: ({ value }: Denotable) => (value === 1 ? 0 : 1),
+    },
+  });
+
+  return env;
+};
+
 const addBinaryIntegerOperationsTo = (env: Environment) => {
   const binaryIntegerOperationSignatures: DenotableFunctionSignature[] = [
     {
@@ -42,12 +153,6 @@ const addBinaryIntegerOperationsTo = (env: Environment) => {
     { name: '<<', fn: (a: number, b: number) => a << b },
     { name: '|', fn: (a: number, b: number) => a | b },
     { name: '^', fn: (a: number, b: number) => a ^ b },
-    { name: '&&', fn: (a: number, b: number) => (a && b ? 1 : 0) },
-    { name: '<=', fn: (a: number, b: number) => (a <= b ? 1 : 0) },
-    { name: '<', fn: (a: number, b: number) => (a < b ? 1 : 0) },
-    { name: '>', fn: (a: number, b: number) => (a > b ? 1 : 0) },
-    { name: '>=', fn: (a: number, b: number) => (a >= b ? 1 : 0) },
-    { name: '||', fn: (a: number, b: number) => (a || b ? 1 : 0) },
   ]) {
     env.set(name, {
       type: 'function',
@@ -102,5 +207,8 @@ export const putBuiltinsOnEnvironemtn = (env: Environment) => {
     addBinaryArithmeticOperationsTo,
     addBinaryIntegerOperationsTo,
     addUnaryIntegerOperationsTo,
+    addNumberComparisonOperationsTo,
+    addBooleanAlgebraOperationsTo,
+    addEqualityOperationsTo,
   ].reduce((acc, builtinsAdder) => builtinsAdder(acc), env);
 };

src/interpreter/denotable.ts

@@ -21,6 +21,7 @@ export type DenotableType =
   | 'null'
   | 'int'
   | 'real'
+  | 'bool'
   | 'string'
   | 'bytearray'
   | 'function'

src/interpreter/interpreter.ts

@@ -29,7 +29,6 @@ const evaluateValue = (
     return { type: 'int', value: value.int };
   }
   if ('name' in value) {
-    logger.debug(`Evaluating variable: ${value.name}`);
     return env.get(value.name);
   }
 
@@ -42,10 +41,6 @@ const evaluatePrimitiveOperation = (
   logger: TracingLogger,
 ) => {
   const { opr, operands, resultBindings, continuations } = primitiveOperation;
-  if (operands.length !== 2) {
-    throw new BadArgumentError('Primitive operations must have 2 operands');
-  }
-
   const operandValues = operands.map(operand =>
     evaluateValue(operand, env, logger.createChild('evaluteValue')),
   );
@@ -56,15 +51,46 @@ const evaluatePrimitiveOperation = (
     continuationEnvironment.set(name, result);
   }
 
-  // return the result of the last continuation
-  return continuations.reduce((_, continuation, i) => {
-    const childLogger = logger.createChild(`continuation[${i}]`);
+  if (result.type === 'bool') {
+    if (continuations.length > 2) {
+      throw new BadArgumentError(
+        `Expected <= 2 continuations for boolean result, got ${continuations.length}`,
+      );
+    }
+    if (continuations.length !== 2) {
+      logger.warn(
+        `Expected 2 continuations for boolean result, got ContinuationLength=(${continuations.length})`,
+      );
+    }
+
+    const [trueContinuation, falseContinuation] = continuations;
+    const childLogger = logger.createChild('continuation[true]');
+    const continuation = result.value ? trueContinuation : falseContinuation;
+    return evaluteContinuationExpression(
+      continuation,
+      continuationEnvironment,
+      childLogger,
+    );
+  }
+
+  if (continuations.length > 1) {
+    throw new BadArgumentError(
+      `Expected <= 1 continuations for non-boolean result, got ${continuations.length}`,
+    );
+  } else if (continuations.length === 0) {
+    logger.warn(
+      `!! Expected 1 continuation in continuation list... implicitly returning result but PLEASE NOTE this is technically undefined behavior !!`,
+    );
+    return result;
+  }
+
+  const [continuation] = continuations;
+  const childLogger = logger.createChild('continuation');
   return evaluteContinuationExpression(
     continuation,
     continuationEnvironment,
     childLogger,
   );
-  }, result);
 };
 
 const evaluteContinuationExpression = (

src/parser/grammar.pegjs

@@ -223,6 +223,7 @@ Value
   / LabelStatement
   / IntStatement
   / RealStatement
+  / BoolStatement
   / StringStatement
 
 VarStatement = VAR _ ident:Identifier { return ident; }
@@ -233,6 +234,8 @@ IntStatement = INT _ int:Integer { return int; }
 
 RealStatement = REAL _ real:Real { return real; }
 
+BoolStatement = BOOL _ bool:Integer { return bool; }
+
 StringStatement = STRING _ string:QuotedString { return string; }
 
 AccessStatement
@@ -286,6 +289,7 @@ ComparisonOperation
   / ">"
   / "<"
   / "||"
+  / "&&"
 
 Integer = digits:("-"? [0-9]+) !"." { return { int: parseInt(digits.join(''), 10) }; }
 
@@ -317,6 +321,8 @@ INT = "INT"
 
 REAL = "REAL"
 
+BOOL = "BOOL"
+
 STRING = "STRING"
 
 APP = "APP"

test/interpreter.spec.ts

@@ -18,6 +18,13 @@ test('Add (1 real) and (3 int) -> result => (real 1 - result) = -3 done with cor
   expect(result).toEqual({ type: 'real', value: -3 });
 });
 
+test('Branching', async () => {
+  const ast = peggyParse(await TestPrograms.Branching);
+
+  const result = await evaluate(ast, testingLogger);
+  expect(result).toEqual({ type: 'real', value: 2 });
+});
+
 /*
 test('String equality', async () => {
   const ast = peggyParse(await TestPrograms.StringEquality);

test/programs/branching.cps

@@ -0,0 +1,10 @@
+PRIMOP(>=, [REAL 0, REAL 1], [resultFalse], [
+    PRIMOP(+, [REAL 2, REAL 4], [result], []),
+    PRIMOP(<=, [INT 1, REAL 1], [resultTrue], [
+        PRIMOP(&&, [VAR resultTrue, VAR resultFalse], [fin], [
+            PRIMOP(-, [REAL 1, REAL 1], [result], []),
+            PRIMOP(+, [REAL 1, REAL 1], [twoWhenFinIsFalse], [])
+        ]),
+        PRIMOP(-, [REAL 1, REAL 1], [result], [])
+    ])
+])

test/programs/index.ts

@@ -7,6 +7,9 @@ export namespace TestPrograms {
   export const PrimopScope = Bun.file(
     join(import.meta.dir + '/primop-scope.cps'),
   ).text();
+  export const Branching = Bun.file(
+    join(import.meta.dir + '/branching.cps'),
+  ).text();
   export const StringEquality = Bun.file(
     join(import.meta.dir + '/string-equal.cps'),
   ).text();

test/signature_match.spec.ts

@@ -1,13 +1,9 @@
 import { expect, test } from 'bun:test';
-import { TestPrograms } from './programs';
-import { peggyParse } from '@/parser';
 import {
-  evaluate,
   type DenotableFunctionSignature,
   denotableTypesEquivalent,
   matchSignature,
 } from '@/interpreter';
-import { testingLogger } from './logger';
 
 test('simple denotable types are equivalent', () => {
   expect(denotableTypesEquivalent('int', 'int')).toBe(true);