Changes:

- Change lambda notation
- Support one parameter notation for lambda

Author: carloslfu

LANGUAGE.md

@@ -55,9 +55,10 @@ Or defining functions:
     returnExpression3
 )
 ```
-`lambda` define an anonimous function:
+`->` a lambda define an anonimous function:
 ```lisp
 (-> [param1 param2 ... paramN] expression)
+(-> param expression)
 ```
 Function composition:
 ```lisp

interpreter.spec.ts

@@ -2,7 +2,7 @@ import test = require('tape')
 import { evalAst, makeAPI } from './interpreter'
 
 test('interpreter', t => {
-  t.plan(26)
+  t.plan(27)
 
   t.deepEqual(
     evalAst(makeAPI({}))(['+', '1', '2', '3']),
@@ -210,18 +210,27 @@ test('interpreter', t => {
 
   t.deepEqual(
     evalAst(makeAPI({}))(
-      [['lambda', ['x', 'y'], ['+', 'x', 'y']], 23, 34],
+      [['->', ['x', 'y'], ['+', 'x', 'y']], 23, 34],
     ),
     ['atom', 57],
     'Lambda definition and application'
   )
 
+  debugger
+  t.deepEqual(
+    evalAst(makeAPI({}))(
+      [['->', 'param', ['+', 'param', '10']], 23],
+    ),
+    ['atom', 33],
+    'Lambda definition and application (one parameter)'
+  )
+
   t.deepEqual(
     evalAst(makeAPI({}))(
       [
         ['.',
-          ['lambda', ['x'], ['+', 'x', '1']],
-          ['lambda', ['x'], ['*', 'x', '3']],
+          ['->', ['x'], ['+', 'x', '1']],
+          ['->', ['x'], ['*', 'x', '3']],
         ],
         3
       ],
@@ -234,8 +243,8 @@ test('interpreter', t => {
     evalAst(makeAPI({}))(
       [
         ['pipe',
-          ['lambda', ['x'], ['+', 'x', '1']],
-          ['lambda', ['x'], ['*', 'x', '3']],
+          ['->', ['x'], ['+', 'x', '1']],
+          ['->', ['x'], ['*', 'x', '3']],
         ],
         3
       ],

interpreter.ts

@@ -56,11 +56,19 @@ export const evalAst = api => ast => {
 export function evaluateFn (api, name, [params, body], args) {
   api._pushScope()
   let argsVal = args.map(api.exp)
-  for (let i = 0, len = params.length; i < len; i++) {
-    if (argsVal[i] !== undefined) {
-      api.setValue(params[i], argsVal[i])
+  if (params instanceof Array) {
+    for (let i = 0, len = params.length; i < len; i++) {
+      if (argsVal[i] !== undefined) {
+        api.setValue(params[i], argsVal[i])
+      } else {
+        return api.evalAst(['throw', `"Missing argument '${params[i]}' in function '${name}'"`])
+      }
+    }
+  } else {
+    if (argsVal[0] !== undefined) {
+      api.setValue(params, argsVal[0])
     } else {
-      return api.evalAst(['throw', `"Missing argument '${params[i]}' in function '${name}'"`])
+      return api.evalAst(['throw', `"Missing argument '${params[0]}' in function '${name}'"`])
     }
   }
   let result = api.exp(body)
@@ -136,7 +144,7 @@ export const atoms = {
     }
   },
   // Lambda definition
-  lambda: (api, [params, body]) => {
+  '->': (api, [params, body]) => {
     return ['fn', [params, body]]
   },
   // Function composition operator
@@ -204,8 +212,6 @@ export const atoms = {
   get: (api, args) => {
     let a = args.map(a => api.exp(a)[1])
     let res = a[0]
-    console.log(a)
-    console.log(a[0])
     for (let i = 1, len = a.length; i < len; i++) {
       res = res[a[i]]
     }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lisp-js-compiler",
-  "version": "0.0.3",
+  "version": "0.0.4",
   "description": "JavaScript compiler / interpreter for Lisp language",
   "main": "lib/index.js",
   "scripts": {