flang - npm Package Compare versions

Comparing version 0.0.1 to 0.0.2

lib/core.js

@@ -51,3 +51,3 @@ 'use strict'
     }
-    return isIdentifier(true) || /^[0-9-]$/.test(char)
+    return isIdentifier(true) || /^[0-9-]$/.test(char) || char === '.'
   }
@@ -62,2 +62,5 @@
       .find(s => s.startsWith(start + peek()))
+    if (start[0] === '/' && isIdentifier()) {
+      throw new Error('Unexpected internal call')
+    }
     return Boolean(starters)
@@ -69,3 +72,3 @@ }
   while (peek() !== '') {
-    while (whitespace.includes(peek())) next()
+    while (peek() && whitespace.includes(peek())) next()
 
@@ -149,2 +152,10 @@ if (peek() === '') break
       return sExpr
+    } else if (peek() === '[') {
+      next()
+      const list = ['/list']
+      while (peek() !== '' && peek() !== ']') {
+        list.push(parseExpression())
+      }
+      next()
+      return list
     } else if (/^[a-zA-Z$_-]+$/.test(peek())) {
@@ -184,3 +195,5 @@ return next()
 
-const unaryOps = []
+const unaryOps = [
+  ['/str', x => x]
+]
 
@@ -193,8 +206,105 @@ const nativeGlobals = Object.fromEntries([
 
-const evaluate = exports.evaluate = (expression) => {
+class Scope {
+  constructor (parent) {
+    this.parent = parent
+    this.variables = new Map()
+  }
+
+  lookup (name) {
+    if (this.variables.has(name)) return this.variables.get(name)
+    if (this.parent) return this.parent.lookup(name)
+    throw new Error('Unknown variable ' + name)
+  }
+}
+
+class Fn {
+  constructor (name, argList, body, parentScope) {
+    this.name = name
+    this.argList = argList
+    this.body = body
+    this.parentScope = parentScope
+    Object.freeze(this)
+  }
+}
+
+const toArgList = argList => {
+  if (argList[0] !== '/list') {
+    throw new Error('function was not given a list as the argument list')
+  }
+  argList.shift()
+  if (!argList.every(x => typeof x === 'string')) {
+    throw new Error('non-name argument in argument list')
+  }
+  return argList
+}
+
+const compile = exports.compile = (expression) => {
+  if (typeof expression === 'string') return expression
+  if (typeof expression === 'number') return expression
+  if (typeof expression === 'boolean') return expression
+
+  let [head, ...args] = expression
+
+  if (Array.isArray(head)) {
+    return `(${compile(head)})(${args.map(compile).join(', ')})`
+  }
+
+  if (head === 'do') {
+    if (!args.length) return 'null'
+    args = args.map(compile)
+    if (args.length === 1) return args[0]
+    const last = args.pop()
+    return '(()=>{' + args.join(';') + ';return ' + last + '})()'
+  } else if (head === 'if') {
+    args = args.map(compile)
+    if (args.length < 3) args.push('null')
+    return `(${args[0]}?${args[1]}:${args[2]})`
+  } else if (head === 'def') {
+    return `let ${args[0]}=${compile(args[1])}`
+  } else if (head === 'set') {
+    return `(${args[0]}=${compile(args[1])})`
+  } else if (head === 'fn') {
+    const name = args[0][0] === '/list' ? '' : args.shift()
+    const argList = args.shift().slice(1).join(',')
+    const body = compile(['do', ...args])
+    if (name) {
+      return `(function ${name}(${argList}){return ${body}})`
+    }
+    return `((${argList}) => ${body})`
+  } else if (head === '/str') {
+    return JSON.stringify(args[0])
+  } else if (head === '/list') {
+    return JSON.stringify(args)
+  } else if (comparisonOperators.includes(head)) {
+    return `(${args.map(compile).reduce((a, b) => `(${a})${head}${b}`)})`
+  } else if (binaryOperators.includes(head)) {
+    return '(' + args.map(compile).join(head) + ')'
+  } else if (typeof head === 'string') {
+    return `${head}(${args.map(compile).join(',')})`
+  }
+
+  throw new Error('unknown expression ' + head)
+}
+
+const evaluate = exports.evaluate = (expression, stack = [new Scope(null)]) => {
+  const scope = stack[stack.length - 1]
+  if (typeof expression === 'string') {
+    return scope.lookup(expression)
+  }
   const isAtom = !Array.isArray(expression)
+  const push = (s = new Scope(scope)) => stack.concat(s)
   if (isAtom) {
     return expression
   }
-  const [head, ...args] = expression
+  let [head, ...args] = expression
+  if (Array.isArray(head)) {
+    head = evaluate(head, stack)
+  }
+  if (head instanceof Fn) {
+    const fnScope = new Scope(head.parentScope)
+    head.argList.forEach((arg, i) => {
+      fnScope.variables.set(arg, evaluate(args[i], stack))
+    })
+    return evaluate(head.body, push(fnScope))
+  }
   if (head in nativeGlobals) {
@@ -205,15 +315,34 @@ const func = nativeGlobals[head]
   if (head === 'do') {
-    for (var i = 0; ; i++) {
-      const isLast = i === args.length - 1
-      const val = evaluate(args[i])
-      if (isLast) return val
+    let val
+    const doStack = push()
+    for (let i = 0; i < args.length; i++) {
+      val = evaluate(args[i], doStack)
     }
+    return val
   } else if (head === 'if') {
     const [cond, then, alternate] = args
-    if (evaluate(cond)) {
-      return evaluate(then)
+    if (evaluate(cond, stack)) {
+      return evaluate(then, stack)
     } else if (alternate != null) {
-      return evaluate(alternate)
+      return evaluate(alternate, stack)
     }
     return null
+  } else if (head === 'fn') {
+    let name
+    if (!Array.isArray(args[0])) {
+      name = args.shift()
+    }
+    if (!Array.isArray(args[0])) {
+      throw new Error('function without arguments list')
+    }
+    const argList = toArgList(args.shift())
+    return new Fn(name, argList, ['do', ...args], scope)
+  } else if (head === 'set') {
+    const value = evaluate(args[1], scope)
+    scope.variables.set(args[0], value)
+    return value
+  } else if (head === 'def') {
+    const value = evaluate(args[1], scope)
+    scope.variables.set(args[0], value)
+    return value
   } else {
@@ -224,4 +353,3 @@ throw new Error('Unknown function or macro ' + head)
 
-exports.parseEvaluate = (source) => {
-  return evaluate(exports.parse(source))
-}
+exports.parseEvaluate = source => evaluate(exports.parse(source))
+exports.parseCompile = source => compile(exports.parse(source))

package.json

 {
   "name": "flang",
-  "version": "0.0.1",
+  "version": "0.0.2",
   "description": "",
@@ -17,3 +17,3 @@ "main": "lib/index.js",
   "scripts": {
-    "test": "mocha",
+    "test": "mocha -r ./register.js test/*.js test/*.fl",
     "lint": "eslint --fix 'lib/**/*.js'"
@@ -31,2 +31,3 @@ },
     "eslint-plugin-standard": "^4.0.0",
+    "flang": "0.0.1",
     "husky": "^3.0.3",
@@ -49,3 +50,6 @@ "mocha": "^6.2.0"
     }
+  },
+  "dependencies": {
+    "pirates": "^4.0.1"
   }
 }

No alert changes

Improved metrics

Total package byte prevSize

11313

64.62%

Lines of code

326

68.04%

Worsened metrics

Dependency count

1

Infinity%

Dev dependency count

10

11.11%

Dependency changes

• + Added

  pirates@^4.0.1

• + Added

  pirates@4.0.7
  (transitive)