src/interpreter/builtins.ts

@@ -1,4 +1,8 @@
-import { type DenotableFunctionSignature, Environment } from '.';
+import {
+  type DenotableFunctionSignature,
+  Environment,
+  type Denotable,
+} from '.';
 
 const addUnaryIntegerOperationsTo = (env: Environment) => {
   const unaryIntegerOperationSignatures: DenotableFunctionSignature[] = [
@@ -14,7 +18,10 @@ const addUnaryIntegerOperationsTo = (env: Environment) => {
   ]) {
     env.set(name, {
       type: 'function',
-      value: { signatures: unaryIntegerOperationSignatures, body: fn },
+      value: {
+        signatures: unaryIntegerOperationSignatures,
+        body: ({ value }: Denotable) => fn(value as number),
+      },
     });
   }
 
@@ -45,7 +52,11 @@ const addBinaryIntegerOperationsTo = (env: Environment) => {
   ]) {
     env.set(name, {
       type: 'function',
-      value: { signatures: binaryIntegerOperationSignatures, body: fn },
+      value: {
+        signatures: binaryIntegerOperationSignatures,
+        body: ({ value: a }: Denotable, { value: b }: Denotable) =>
+          fn(a as number, b as number),
+      },
     });
   }
 
@@ -76,19 +87,21 @@ const addBinaryArithmeticOperationsTo = (env: Environment) => {
   ]) {
     env.set(name, {
       type: 'function',
-      value: { signatures: binaryArithmeticSignatures, body: fn },
+      value: {
+        signatures: binaryArithmeticSignatures,
+        body: ({ value: a }: Denotable, { value: b }: Denotable) =>
+          fn(a as number, b as number),
+      },
     });
   }
 
   return env;
 };
 
-export const environmentWithBuiltins = () => {
+export const putBuiltinsOnEnvironemtn = (env: Environment) => {
-  const environment = new Environment();
-
   return [
     addBinaryArithmeticOperationsTo,
     addBinaryIntegerOperationsTo,
     addUnaryIntegerOperationsTo,
-  ].reduce((acc, builtinsAdder) => builtinsAdder(acc), environment);
+  ].reduce((acc, builtinsAdder) => builtinsAdder(acc), env);
 };

src/interpreter/denotable.ts

@@ -1,13 +1,15 @@
 import type { Identifier } from '@/parser';
+import { testingLogger } from '@t/logger';
 
 export type UnionDenotableType =
   | Array<DenotableType | DenotableFunctionSignature>
   | DenotableType
-  | DenotableFunctionSignature;
+  | DenotableFunctionSignature
+  | Array<UnionDenotableType>;
 
 export type DenotableFunctionSignature = {
   arguments: Array<UnionDenotableType>;
-  return: UnionDenotableType;
+  return: DenotableType;
 };
 
 export type DenotableFunction = {
@@ -37,35 +39,55 @@ export type Denotable = {
   value: DenotableValue;
 };
 
-export const functionSignaturesEqual = (
+export const denotableTypesEquivalent = (
-  a: DenotableFunctionSignature,
+  a: UnionDenotableType,
-  b: DenotableFunctionSignature,
+  b: UnionDenotableType,
 ): boolean => {
-  if (a.arguments.length !== b.arguments.length) {
+  if (typeof a !== typeof b) return false;
-    return false;
-  }
 
-  if (typeof a.return !== typeof b.return) {
+  if (Array.isArray(a) && Array.isArray(b)) {
-    return false;
+    if (a.length !== b.length) return false;
+    for (let i = 0; i < a.length; i++) {
+      if (!denotableTypesEquivalent(a[i], b[i])) return false;
+    }
+    return true;
   }
 
   if (
-    typeof a.return === 'object' &&
+    typeof a === 'object' &&
-    typeof b.return === 'object' &&
+    typeof b === 'object' &&
-    'return' in a.return &&
+    'arguments' in a &&
-    'return' in b.return
+    'arguments' in b
   ) {
-    return functionSignaturesEqual(a.return, b.return);
+    if (a.arguments.length !== b.arguments.length) return false;
+    if (!denotableTypesEquivalent(a.return, b.return)) return false;
+    for (let i = 0; i < a.arguments.length; i++) {
+      if (!denotableTypesEquivalent(a.arguments[i], b.arguments[i])) {
+        return false;
+      }
+    }
+    return true;
   }
+
+  if (a === b) return true;
+
+  return false;
 };
 
 export const matchSignature = (
-  args: Array<DenotableFunction | DenotableType>,
+  args: Array<UnionDenotableType>,
   signatures: Array<DenotableFunctionSignature>,
 ): DenotableFunctionSignature | undefined => {
   return signatures.find(signature => {
-    if (args.length !== signature.arguments.length) {
+    if (args.length !== signature.arguments.length) return false;
-      return false;
+
-    }
+    return args.every((arg, i) => {
+      const argSignature = signature.arguments[i];
+      if (Array.isArray(argSignature)) {
+        return argSignature.some(a => denotableTypesEquivalent(a, arg));
+      }
+
+      return denotableTypesEquivalent(arg, signature.arguments[i]);
+    });
   });
 };

src/interpreter/environment.ts

@@ -1,17 +1,13 @@
-import { UnknownSymbolError, InvalidType } from '@/utils';
+import { UnknownSymbolError, InvalidType, type TracingLogger } from '@/utils';
-import type {
+import { matchSignature, type Denotable } from '.';
-  Denotable,
-  DenotableFunction,
-  DenotableFunctionSignature,
-  DenotableType,
-  DenotableValue,
-} from '.';
 
 export class Environment {
   private scope: Map<string, Denotable>;
   private parent: Environment | null;
+  private logger: TracingLogger;
 
-  constructor(parent: Environment | null = null) {
+  constructor(logger: TracingLogger, parent: Environment | null = null) {
+    this.logger = logger;
     this.parent = parent;
     this.scope = new Map();
   }
@@ -22,10 +18,12 @@ export class Environment {
 
   public get(name: string): Denotable {
     if (this.scope.has(name)) {
+      this.logger.debug(`Found Name=(${name}) in current scope`);
       return this.scope.get(name)!;
     }
 
     if (this.parent) {
+      this.logger.debug(`Looking for Name=(${name}) in parent scope`);
       return this.parent.get(name);
     }
 
@@ -34,18 +32,21 @@ export class Environment {
 
   public has(name: string): boolean {
     if (this.scope.has(name)) {
+      this.logger.debug(`Found Name=(${name}) in current scope`);
       return true;
     }
 
     if (this.parent) {
+      this.logger.debug(`Found Name=(${name}) in current scope`);
       return this.parent.has(name);
     }
 
+    this.logger.debug(`Name=(${name}) not found in any scope`);
     return false;
   }
 
   public createChild(): Environment {
-    return new Environment(this);
+    return new Environment(this.logger.createChild('Env'), this);
   }
 
   public apply(name: string, args: Denotable[]): Denotable {
@@ -54,6 +55,29 @@ export class Environment {
       throw new InvalidType(name + ' is not a valid function');
     }
 
-    return { type: 'real', value: 0 };
+    const argTypes = args.map(arg => {
+      const { type, value } = arg;
+      const isFunction =
+        type === 'function' &&
+        typeof value === 'object' &&
+        value &&
+        'signatures' in value;
+      if (isFunction) {
+        return value.signatures;
+      }
+      return type;
+    });
+
+    const appliedSignature = matchSignature(argTypes, fn.value.signatures);
+    if (!appliedSignature) {
+      throw new InvalidType(`No matching signature for ${name}`);
+    }
+
+    this.logger.debug(
+      `Applying Function=(${name}) with Args=(${JSON.stringify(args)}) with Signature=(${JSON.stringify(appliedSignature)})`,
+    );
+
+    const value = fn.value.body.apply(this, args);
+    return { type: appliedSignature.return, value };
   }
 }

src/interpreter/interpreter.ts

@@ -11,6 +11,7 @@ import {
   NotImplementedError,
   type TracingLogger,
 } from '@/utils';
+import { putBuiltinsOnEnvironemtn } from './builtins';
 
 const evaluateValue = (
   value: Value,
@@ -49,7 +50,7 @@ const evaluatePrimitiveOperation = (
     evaluateValue(operand, env, logger.createChild('evaluteValue')),
   );
 
-  let result: Denotable = { type: 'null', value: null };
+  const result = env.apply(opr, operandValues);
   const continuationEnvironment = env.createChild();
 
   // return the result of the last continuation
@@ -105,13 +106,15 @@ export const evaluate = async (
   ast: Program,
   logger: TracingLogger,
 ): Promise<Denotable> => {
-  const environment = new Environment();
+  const globalEnvironment = putBuiltinsOnEnvironemtn(
+    new Environment(logger.createChild('Root')),
+  );
 
   return ast.reduce((_, continuation, i) => {
     const exprLogger = logger.createChild(`statement[${i}]`);
     return evaluteContinuationExpression(
       continuation as ContinuationExpression,
-      environment,
+      globalEnvironment,
       exprLogger,
     );
   }, null);

test/signature_match.spec.ts

@@ -4,10 +4,59 @@ 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);
+  expect(denotableTypesEquivalent('int', 'real')).toBe(false);
+  expect(denotableTypesEquivalent('int', 'null')).toBe(false);
+  expect(denotableTypesEquivalent('null', 'null')).toBe(true);
+});
+
+test('union data types are equivalent', () => {
+  expect(denotableTypesEquivalent(['int', 'real'], ['int', 'real'])).toBe(true);
+  expect(denotableTypesEquivalent('int', ['int', 'real'])).toBe(false);
+});
+
+test('function data types are equivalent', () => {
+  expect(
+    denotableTypesEquivalent(
+      [
+        {
+          arguments: ['int', 'real'],
+          return: 'int',
+        },
+      ],
+      [
+        {
+          arguments: ['int', 'real'],
+          return: 'int',
+        },
+      ],
+    ),
+  ).toBe(true);
+
+  expect(
+    denotableTypesEquivalent(
+      [
+        {
+          arguments: ['int', 'real'],
+          return: 'real',
+        },
+      ],
+      [
+        {
+          arguments: ['int', 'real'],
+          return: 'int',
+        },
+      ],
+    ),
+  ).toBe(false);
+});
+
 test('matches simple signatures', async () => {
   const simpleSignature: DenotableFunctionSignature[] = [
     {
@@ -39,3 +88,73 @@ test('finds first match', async () => {
     simpleSignature[1],
   );
 });
+
+test('finds first match with a function signature', async () => {
+  const testSignature: DenotableFunctionSignature = {
+    arguments: ['int', 'real'],
+    return: 'int',
+  };
+
+  const simpleSignature: DenotableFunctionSignature[] = [
+    {
+      arguments: ['int', 'int'],
+      return: 'int',
+    },
+    {
+      arguments: [[testSignature, 'real'], 'int'],
+      return: 'function',
+    },
+  ];
+
+  expect(matchSignature(['int', 'int'], simpleSignature)).toEqual(
+    simpleSignature[0],
+  );
+
+  expect(matchSignature(['real', 'int'], simpleSignature)).toEqual(
+    simpleSignature[1],
+  );
+
+  expect(matchSignature([testSignature, 'int'], simpleSignature)).toEqual(
+    simpleSignature[1],
+  );
+});
+
+test('finds first match with a function with many signatures', async () => {
+  const testSignature: DenotableFunctionSignature[] = [
+    {
+      arguments: ['int', 'real'],
+      return: 'int',
+    },
+    {
+      arguments: ['int', 'int'],
+      return: 'int',
+    },
+  ];
+
+  const simpleSignature: DenotableFunctionSignature[] = [
+    {
+      arguments: ['int', 'int'],
+      return: 'int',
+    },
+    {
+      arguments: [[testSignature, 'real'], 'int'],
+      return: 'function',
+    },
+  ];
+
+  expect(matchSignature(['int', 'int'], simpleSignature)).toEqual(
+    simpleSignature[0],
+  );
+
+  expect(matchSignature(['real', 'int'], simpleSignature)).toEqual(
+    simpleSignature[1],
+  );
+
+  expect(matchSignature([testSignature, 'int'], simpleSignature)).toEqual(
+    simpleSignature[1],
+  );
+
+  expect(
+    matchSignature([[testSignature[0]], 'int'], simpleSignature),
+  ).toBeUndefined();
+});