diff --git a/package.json b/package.json
index 693ecc51..2017873e 100644
--- a/package.json
+++ b/package.json
@@ -1,4 +1,5 @@
 {
+  "license": "Apache-2.0",
   "devDependencies": {
     "@types/chalk": "^0.4.31",
     "@types/diff": "^3.2.2",
diff --git a/src/ast.ts b/src/ast.ts
index 82aad4ba..13f668ef 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -112,6 +112,7 @@ export enum NodeKind {
   ENUMVALUE,            // is also declaration
   EXPORT,
   EXPORTIMPORT,
+  EXPORTMEMBER,
   EXPRESSION,
   INTERFACE,
   FOR,
@@ -875,11 +876,11 @@ export abstract class Statement extends Node {
     return stmt;
   }
 
-  static createExportMember(identifier: IdentifierExpression, asIdentifier: IdentifierExpression | null, range: Range): ExportMember {
+  static createExportMember(identifier: IdentifierExpression, externalIdentifier: IdentifierExpression | null, range: Range): ExportMember {
     const elem: ExportMember = new ExportMember();
     elem.range = range;
     (elem.identifier = identifier).parent = elem;
-    if (elem.asIdentifier = asIdentifier) (<IdentifierExpression>asIdentifier).parent = elem;
+    (elem.externalIdentifier = externalIdentifier ? <IdentifierExpression>externalIdentifier : identifier).parent = elem;
     return elem;
   }
 
@@ -1272,14 +1273,15 @@ export class ExportImportStatement extends Node {
 
 export class ExportMember extends Node {
 
+  kind = NodeKind.EXPORTMEMBER;
   identifier: IdentifierExpression;
-  asIdentifier: IdentifierExpression | null;
+  externalIdentifier: IdentifierExpression;
 
   serialize(sb: string[]): void {
     this.identifier.serialize(sb);
-    if (this.asIdentifier) {
+    if (this.externalIdentifier.name != this.identifier.name) {
       sb.push(" as ");
-      (<IdentifierExpression>this.asIdentifier).serialize(sb);
+      (<IdentifierExpression>this.externalIdentifier).serialize(sb);
     }
   }
 }
diff --git a/src/compiler.ts b/src/compiler.ts
index b1c2446b..48a55981 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -1,8 +1,9 @@
-import { Module, MemorySegment, UnaryOp, BinaryOp, HostOp } from "./binaryen";
+import { Module, MemorySegment, UnaryOp, BinaryOp, HostOp, Type as BinaryenType } from "./binaryen";
 import { DiagnosticCode, DiagnosticMessage, DiagnosticEmitter } from "./diagnostics";
 import { hasModifier } from "./parser";
 import { Program } from "./program";
-import { CharCode, U64 } from "./util";
+import { CharCode, I64, U64 } from "./util";
+import { Token } from "./tokenizer";
 import {
 
   NodeKind,
@@ -16,10 +17,12 @@ import {
   DoStatement,
   EmptyStatement,
   EnumDeclaration,
+  EnumValueDeclaration,
   ExpressionStatement,
   FunctionDeclaration,
   ForStatement,
   IfStatement,
+  ImportStatement,
   MethodDeclaration,
   ModifierKind,
   NamespaceDeclaration,
@@ -93,6 +96,8 @@ export class Compiler extends DiagnosticEmitter {
   memoryOffset: U64 = new U64(8, 0); // leave space for (any size of) NULL
   memorySegments: MemorySegment[] = new Array();
 
+  statements: BinaryenExpressionRef[] = new Array(); // TODO: make start function
+
   static compile(program: Program, options: Options | null = null): Module {
     const compiler: Compiler = new Compiler(program, options);
     return compiler.compile();
@@ -141,6 +146,9 @@ export class Compiler extends DiagnosticEmitter {
           }
           break;
 
+        case NodeKind.IMPORT:
+          break;
+
         case NodeKind.NAMESPACE:
           if (hasModifier(ModifierKind.EXPORT, (<NamespaceDeclaration>statement).modifiers)) {
             const ns: Namespace = Namespace.create(<NamespaceDeclaration>statement).exportAs((<NamespaceDeclaration>statement).identifier.name);
@@ -162,7 +170,11 @@ export class Compiler extends DiagnosticEmitter {
           break;
 
         case NodeKind.EXPORT:
-          // obtain referenced declaration and export that
+          // TODO: obtain referenced declaration and export that
+          break;
+
+        default:
+          this.statements.push(this.compileStatement(statement));
           break;
       }
     }
@@ -186,7 +198,17 @@ export class Compiler extends DiagnosticEmitter {
   }
 
   compileEnum(en: Enum): void {
-    throw new Error("not implemented");
+    for (let i: i32 = 0, k = en.declaration.members.length; i < k; ++i) {
+      const declaration: EnumValueDeclaration =  en.declaration.members[i];
+      const name: string = this.program.mangleName(declaration);
+      const value: BinaryenExpressionRef = declaration.value
+        ? this.compileExpression(<Expression>declaration.value, Type.i32)
+        : this.module.createI32(i); // TODO
+      this.module.addGlobal(name, BinaryenType.I32, false, value);
+      if (en.exportName != null) {
+        // TODO: WASM does not yet support non-function exports
+      }
+    }
   }
 
   compileFunction(fn: Function): void {
@@ -230,6 +252,17 @@ export class Compiler extends DiagnosticEmitter {
 
   // statements
 
+  enterBreakContext(): string {
+    if (this.breakMinor == 0)
+      ++this.breakMajor;
+    ++this.breakMinor;
+    return this.breakMajor.toString() + "." + this.breakMinor.toString();
+  }
+
+  leaveBreakContext(): void {
+    --this.breakMinor;
+  }
+
   compileStatement(statement: Statement): BinaryenExpressionRef {
     switch (statement.kind) {
 
@@ -283,7 +316,7 @@ export class Compiler extends DiagnosticEmitter {
     const children: BinaryenExpressionRef[] = new Array(substatements.length);
     for (let i: i32 = 0, k: i32 = substatements.length; i < k; ++i)
       children[i] = this.compileStatement(substatements[i]);
-    return this.module.createBlock(null, children);
+    return this.module.createBlock(null, children, BinaryenType.None);
   }
 
   compileBreakStatement(statement: BreakStatement): BinaryenExpressionRef {
@@ -303,21 +336,20 @@ export class Compiler extends DiagnosticEmitter {
   }
 
   compileExpressionStatement(statement: ExpressionStatement): BinaryenExpressionRef {
-    const expression: BinaryenExpressionRef = this.compileExpression(statement.expression, Type.void);
-    return this.currentType == Type.void ? expression : this.module.createDrop(expression);
+    return this.compileExpression(statement.expression, Type.void);
   }
 
   compileForStatement(statement: ForStatement): BinaryenExpressionRef {
     const initializer: BinaryenExpressionRef = statement.initializer ? this.compileStatement(<Statement>statement.initializer) : 0;
-    const condition: BinaryenExportRef = statement.condition ? this.compileExpression(<Expression>statement.condition, Type.i32) : 0;
-    const incrementor: BinaryenExportRef = statement.incrementor ? this.compileExpression(<Expression>statement.incrementor, Type.void) : 0;
+    const condition: BinaryenExpressionRef = statement.condition ? this.compileExpression(<Expression>statement.condition, Type.i32) : 0;
+    const incrementor: BinaryenExpressionRef = statement.incrementor ? this.compileExpression(<Expression>statement.incrementor, Type.void) : 0;
     throw new Error("not implemented");
   }
 
   compileIfStatement(statement: IfStatement): BinaryenExpressionRef {
     const condition: BinaryenExpressionRef = this.compileExpression(statement.condition, Type.i32);
     const ifTrue: BinaryenExpressionRef = this.compileStatement(statement.statement);
-    const ifFalse: BinaryenExportRef = statement.elseStatement ? this.compileStatement(<Statement>statement.elseStatement) : 0;
+    const ifFalse: BinaryenExpressionRef = statement.elseStatement ? this.compileStatement(<Statement>statement.elseStatement) : 0;
     return this.module.createIf(condition, ifTrue, ifFalse);
   }
 
@@ -346,72 +378,85 @@ export class Compiler extends DiagnosticEmitter {
   }
 
   compileWhileStatement(statement: WhileStatement): BinaryenExpressionRef {
-    throw new Error("not implemented");
+    const condition: BinaryenExpressionRef = this.compileExpression(statement.condition, Type.i32);
+    const label: string = this.enterBreakContext();
+    const breakLabel: string = "break$" + label;
+    const continueLabel: string = "continue$" + label;
+    const body: BinaryenExpressionRef = this.compileStatement(statement.statement);
+    this.leaveBreakContext();
+    return this.module.createBlock(breakLabel, [
+      this.module.createLoop(continueLabel,
+        this.module.createIf(condition, this.module.createBlock("", [
+          body,
+          this.module.createBreak(continueLabel)
+        ]))
+      )
+    ]);
   }
 
   // expressions
 
-  compileExpression(expression: Expression, resultType: Type): BinaryenExpressionRef {
-    this.currentType = resultType;
+  compileExpression(expression: Expression, contextualType: Type, convert: bool = true): BinaryenExpressionRef {
+    this.currentType = contextualType;
 
     let expr: BinaryenExpressionRef;
     switch (expression.kind) {
 
       case NodeKind.ASSERTION:
-        expr = this.compileAssertionExpression(<AssertionExpression>expression, resultType);
+        expr = this.compileAssertionExpression(<AssertionExpression>expression, contextualType);
         break;
 
       case NodeKind.BINARY:
-        expr = this.compileBinaryExpression(<BinaryExpression>expression, resultType);
+        expr = this.compileBinaryExpression(<BinaryExpression>expression, contextualType);
         break;
 
       case NodeKind.CALL:
-        expr = this.compileCallExpression(<CallExpression>expression, resultType);
+        expr = this.compileCallExpression(<CallExpression>expression, contextualType);
         break;
 
       case NodeKind.ELEMENTACCESS:
-        expr = this.compileElementAccessExpression(<ElementAccessExpression>expression, resultType);
+        expr = this.compileElementAccessExpression(<ElementAccessExpression>expression, contextualType);
         break;
 
       case NodeKind.IDENTIFIER:
-        expr = this.compileIdentifierExpression(<IdentifierExpression>expression, resultType);
+        expr = this.compileIdentifierExpression(<IdentifierExpression>expression, contextualType);
         break;
 
       case NodeKind.LITERAL:
-        expr = this.compileLiteralExpression(<LiteralExpression>expression, resultType);
+        expr = this.compileLiteralExpression(<LiteralExpression>expression, contextualType);
         break;
 
       case NodeKind.NEW:
-        expr = this.compileNewExpression(<NewExpression>expression, resultType);
+        expr = this.compileNewExpression(<NewExpression>expression, contextualType);
         break;
 
       case NodeKind.PARENTHESIZED:
-        expr = this.compileParenthesizedExpression(<ParenthesizedExpression>expression, resultType);
+        expr = this.compileParenthesizedExpression(<ParenthesizedExpression>expression, contextualType);
         break;
 
       case NodeKind.PROPERTYACCESS:
-        expr = this.compilePropertyAccessExpression(<PropertyAccessExpression>expression, resultType);
+        expr = this.compilePropertyAccessExpression(<PropertyAccessExpression>expression, contextualType);
         break;
 
       case NodeKind.SELECT:
-        expr = this.compileSelectExpression(<SelectExpression>expression, resultType);
+        expr = this.compileSelectExpression(<SelectExpression>expression, contextualType);
         break;
 
       case NodeKind.UNARYPOSTFIX:
-        expr = this.compileUnaryPostfixExpression(<UnaryPostfixExpression>expression, resultType);
+        expr = this.compileUnaryPostfixExpression(<UnaryPostfixExpression>expression, contextualType);
         break;
 
       case NodeKind.UNARYPREFIX:
-        expr = this.compileUnaryPrefixExpression(<UnaryPrefixExpression>expression, resultType);
+        expr = this.compileUnaryPrefixExpression(<UnaryPrefixExpression>expression, contextualType);
         break;
 
       default:
         throw new Error("unexpected expression kind");
     }
 
-    if (this.currentType != resultType) {
-      expr = this.convertExpression(expr, this.currentType, resultType);
-      this.currentType = resultType;
+    if (convert && this.currentType != contextualType) {
+      expr = this.convertExpression(expr, this.currentType, contextualType);
+      this.currentType = contextualType;
     }
 
     return expr;
@@ -580,6 +625,221 @@ export class Compiler extends DiagnosticEmitter {
   }
 
   compileBinaryExpression(expression: BinaryExpression, contextualType: Type): BinaryenExpressionRef {
+    let op: BinaryOp;
+    let left: BinaryenExpressionRef;
+    let right: BinaryenExpressionRef;
+    let compound: Token = 0;
+
+    switch (expression.operator) {
+
+      case Token.LESSTHAN:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.LtF32
+           : this.currentType == Type.f64
+           ? BinaryOp.LtF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.LtI64
+           : BinaryOp.LtI32;
+        this.currentType = Type.bool;
+        break;
+
+      case Token.GREATERTHAN:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.GtF32
+           : this.currentType == Type.f64
+           ? BinaryOp.GtF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.GtI64
+           : BinaryOp.GtI32;
+        this.currentType = Type.bool;
+        break;
+
+      case Token.LESSTHAN_EQUALS:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.LeF32
+           : this.currentType == Type.f64
+           ? BinaryOp.LeF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.LeI64
+           : BinaryOp.LeI32;
+        this.currentType = Type.bool;
+        break;
+
+      case Token.GREATERTHAN_EQUALS:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.GeF32
+           : this.currentType == Type.f64
+           ? BinaryOp.GeF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.GeI64
+           : BinaryOp.GeI32;
+        this.currentType = Type.bool;
+        break;
+
+      case Token.EQUALS_EQUALS:
+      case Token.EQUALS_EQUALS_EQUALS:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.EqF32
+           : this.currentType == Type.f64
+           ? BinaryOp.EqF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.EqI64
+           : BinaryOp.EqI32;
+        this.currentType = Type.bool;
+        break;
+
+      case Token.PLUS_EQUALS:
+        compound = Token.EQUALS;
+      case Token.PLUS:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.AddF32
+           : this.currentType == Type.f64
+           ? BinaryOp.AddF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.AddI64
+           : BinaryOp.AddI32;
+        break;
+
+      case Token.MINUS_EQUALS:
+        compound = Token.EQUALS;
+      case Token.MINUS:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.SubF32
+           : this.currentType == Type.f64
+           ? BinaryOp.SubF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.SubI64
+           : BinaryOp.SubI32;
+        break;
+
+      case Token.ASTERISK_EQUALS:
+        compound = Token.EQUALS;
+      case Token.ASTERISK:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.MulF32
+           : this.currentType == Type.f64
+           ? BinaryOp.MulF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.MulI64
+           : BinaryOp.MulI32;
+        break;
+
+      case Token.SLASH_EQUALS:
+        compound = Token.EQUALS;
+      case Token.SLASH:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType == Type.f32
+           ? BinaryOp.DivF32
+           : this.currentType == Type.f64
+           ? BinaryOp.DivF64
+           : this.currentType.isLongInteger
+           ? BinaryOp.DivI64
+           : BinaryOp.DivI32;
+        break;
+
+      case Token.PERCENT_EQUALS:
+        compound = Token.EQUALS;
+      case Token.PERCENT:
+        left = this.compileExpression(expression.left, contextualType, false);
+        right = this.compileExpression(expression.right, this.currentType);
+        if (this.currentType.isAnyFloat)
+          throw new Error("not implemented"); // TODO: fmod
+        op = this.currentType.isLongInteger
+           ? BinaryOp.RemI64
+           : BinaryOp.RemI32;
+        break;
+
+      case Token.LESSTHAN_LESSTHAN_EQUALS:
+        compound = Token.EQUALS;
+      case Token.LESSTHAN_LESSTHAN:
+        left = this.compileExpression(expression.left, contextualType.isAnyFloat ? Type.i64 : contextualType);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType.isLongInteger
+           ? BinaryOp.ShlI64
+           : BinaryOp.ShlI32;
+        break;
+
+      case Token.GREATERTHAN_GREATERTHAN_EQUALS:
+        compound = Token.EQUALS;
+      case Token.GREATERTHAN_GREATERTHAN:
+        left = this.compileExpression(expression.left, contextualType.isAnyFloat ? Type.i64 : contextualType);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType.isSignedInteger
+           ? this.currentType.isLongInteger
+             ? BinaryOp.ShrI64
+             : BinaryOp.ShrI32
+           : this.currentType.isLongInteger
+             ? BinaryOp.ShrU64
+             : BinaryOp.ShrU32;
+        break;
+
+      case Token.GREATERTHAN_GREATERTHAN_GREATERTHAN_EQUALS:
+        compound = Token.EQUALS;
+      case Token.GREATERTHAN_GREATERTHAN_GREATERTHAN:
+        left = this.compileExpression(expression.left, contextualType.isAnyFloat ? Type.u64 : contextualType);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType.isLongInteger
+           ? BinaryOp.ShrU64
+           : BinaryOp.ShrU32;
+        break;
+
+      case Token.AMPERSAND_EQUALS:
+        compound = Token.EQUALS;
+      case Token.AMPERSAND:
+        left = this.compileExpression(expression.left, contextualType.isAnyFloat ? Type.i64 : contextualType);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType.isLongInteger
+           ? BinaryOp.AndI64
+           : BinaryOp.AndI32;
+        break;
+
+      case Token.BAR_EQUALS:
+        compound = Token.EQUALS;
+      case Token.BAR:
+        left = this.compileExpression(expression.left, contextualType.isAnyFloat ? Type.i64 : contextualType);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType.isLongInteger
+           ? BinaryOp.OrI64
+           : BinaryOp.OrI32;
+        break;
+
+      case Token.CARET_EQUALS:
+        compound = Token.EQUALS;
+      case Token.CARET:
+        left = this.compileExpression(expression.left, contextualType.isAnyFloat ? Type.i64 : contextualType);
+        right = this.compileExpression(expression.right, this.currentType);
+        op = this.currentType.isLongInteger
+           ? BinaryOp.XorI64
+           : BinaryOp.XorI32;
+        break;
+
+      default:
+        throw new Error("not implemented");
+    }
+
+    return compound
+      ? this.compileAssignment(expression.left, this.module.createBinary(op, left, right))
+      : this.module.createBinary(op, left, right);
+  }
+
+  compileAssignment(expression: Expression, value: BinaryenExpressionRef): BinaryenExpressionRef {
     throw new Error("not implemented");
   }
 
@@ -599,23 +859,27 @@ export class Compiler extends DiagnosticEmitter {
     switch (expression.literalKind) {
       // case LiteralKind.ARRAY:
 
-      case LiteralKind.FLOAT:
-        if (contextualType == Type.f32)
-          return this.module.createF32((<FloatLiteralExpression>expression).value);
+      case LiteralKind.FLOAT: {
+        const floatValue: f64 = (<FloatLiteralExpression>expression).value;
+        if (contextualType == Type.f32 && (Math.fround(floatValue) as f64) == floatValue)
+          return this.module.createF32(floatValue);
         this.currentType = Type.f64;
-        return this.module.createF64((<FloatLiteralExpression>expression).value);
+        return this.module.createF64(floatValue);
+      }
 
-      case LiteralKind.INTEGER:
-        if (contextualType == Type.bool)
-          return this.module.createI32((<IntegerLiteralExpression>expression).value.isOdd ? 1 : 0)
+      case LiteralKind.INTEGER: {
+        const intValue: I64 = (<IntegerLiteralExpression>expression).value;
+        if (contextualType == Type.bool && (intValue.isZero || intValue.isOne))
+          return this.module.createI32(intValue.isZero ? 0 : 1);
         if (contextualType.isLongInteger)
-          return this.module.createI64((<IntegerLiteralExpression>expression).value.lo, (<IntegerLiteralExpression>expression).value.hi);
-        const value: i32 = (<IntegerLiteralExpression>expression).value.toI32();
-        if (contextualType.isSmallInteger)
-          return contextualType.isSignedInteger
-            ? this.module.createI32(value << contextualType.smallIntegerShift >> contextualType.smallIntegerShift)
-            : this.module.createI32(value & contextualType.smallIntegerMask);
-        return this.module.createI32(value);
+          return this.module.createI64(intValue.lo, intValue.hi);
+        if (!intValue.fitsInI32) {
+          this.currentType = Type.i64;
+          return this.module.createI64(intValue.lo, intValue.hi);
+        }
+        this.currentType = Type.i32;
+        return this.module.createI32(intValue.toI32());
+      }
 
       // case LiteralKind.OBJECT:
       // case LiteralKind.REGEXP:
@@ -644,10 +908,70 @@ export class Compiler extends DiagnosticEmitter {
   }
 
   compileUnaryPostfixExpression(expression: UnaryPostfixExpression, contextualType: Type): BinaryenExpressionRef {
-    throw new Error("not implemented");
+    let operand: BinaryenExpressionRef;
+    let op: UnaryOp;
+
+    switch (expression.operator) {
+
+      case Token.PLUS_PLUS:
+      case Token.MINUS_MINUS:
+
+      default:
+        throw new Error("not implemented");
+    }
+    // return this.module.createBinary(op, operand);
   }
 
   compileUnaryPrefixExpression(expression: UnaryPrefixExpression, contextualType: Type): BinaryenExpressionRef {
-    throw new Error("not implemented");
+    let operand: BinaryenExpressionRef;
+    let op: UnaryOp;
+
+    switch (expression.operator) {
+
+      case Token.PLUS:
+        return this.compileExpression(expression.expression, contextualType);
+
+      case Token.MINUS:
+        operand = this.compileExpression(expression.expression, contextualType);
+        if (this.currentType == Type.f32)
+          op = UnaryOp.NegF32;
+        else if (this.currentType == Type.f64)
+          op = UnaryOp.NegF64;
+        else
+          return this.currentType.isLongInteger
+            ? this.module.createBinary(BinaryOp.SubI64, this.module.createI64(0, 0), operand)
+            : this.module.createBinary(BinaryOp.SubI32, this.module.createI32(0), operand);
+        break;
+
+      // case Token.PLUS_PLUS:
+      // case Token.MINUS_MINUS:
+
+      case Token.EXCLAMATION:
+        operand = this.compileExpression(expression.expression, Type.bool, false);
+        if (this.currentType == Type.f32) {
+          this.currentType = Type.bool;
+          return this.module.createBinary(BinaryOp.EqF32, operand, this.module.createF32(0));
+        }
+        if (this.currentType == Type.f64) {
+          this.currentType = Type.bool;
+          return this.module.createBinary(BinaryOp.EqF64, operand, this.module.createF64(0));
+        }
+        op = this.currentType.isLongInteger
+           ? UnaryOp.EqzI64 // TODO: does this yield i64 0/1?
+           : UnaryOp.EqzI32;
+        this.currentType = Type.bool;
+        break;
+
+      case Token.TILDE:
+        operand = this.compileExpression(expression.expression, contextualType.isAnyFloat ? Type.i64 : contextualType);
+        return this.currentType.isLongInteger
+          ? this.module.createBinary(BinaryOp.XorI64, operand, this.module.createI64(-1, -1))
+          : this.module.createBinary(BinaryOp.XorI32, operand, this.module.createI32(-1));
+
+      default:
+        throw new Error("not implemented");
+    }
+
+    return this.module.createUnary(op, operand);
   }
 }
diff --git a/src/diagnostics.ts b/src/diagnostics.ts
index 5dfb9b14..b70b8891 100644
--- a/src/diagnostics.ts
+++ b/src/diagnostics.ts
@@ -151,6 +151,7 @@ export abstract class DiagnosticEmitter {
     const message: DiagnosticMessage = DiagnosticMessage.create(code, category, arg0, arg1).withRange(range);
     this.diagnostics.push(message);
     console.log(formatDiagnosticMessage(message, true, true)); // temporary
+    console.log(new Error().stack);
   }
 
   error(code: DiagnosticCode, range: Range, arg0: string | null = null, arg1: string | null = null): void {
diff --git a/src/parser.ts b/src/parser.ts
index caf38bca..cb971a7b 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -11,7 +11,7 @@ import { Program } from "./program";
 import { Source } from "./reflection";
 import { Tokenizer, Token, Range } from "./tokenizer";
 import { DiagnosticCode, DiagnosticMessage, DiagnosticEmitter, formatDiagnosticMessage } from "./diagnostics";
-import { I64 } from "./util";
+import { I64, normalizePath, resolvePath } from "./util";
 import {
 
   NodeKind,
@@ -67,6 +67,7 @@ export class Parser extends DiagnosticEmitter {
 
   program: Program;
   backlog: string[] = new Array();
+  seenlog: Set<string> = new Set();
 
   constructor() {
     super();
@@ -74,12 +75,14 @@ export class Parser extends DiagnosticEmitter {
   }
 
   parseFile(text: string, path: string, isEntry: bool): void {
-    if (path.startsWith("./"))
-      path = path.substring(2);
+    const normalizedPath: string = normalizePath(path);
     for (let i: i32 = 0, k: i32 = this.program.sources.length; i < k; ++i)
-      if (this.program.sources[i].path == path)
+      if (this.program.sources[i].normalizedPath == normalizedPath)
         throw Error("duplicate source");
 
+    if (isEntry)
+      this.seenlog.add(normalizedPath);
+
     const source: Source = new Source(path, text, isEntry);
     this.program.sources.push(source);
 
@@ -189,6 +192,8 @@ export class Parser extends DiagnosticEmitter {
   finish(): Program {
     if (this.backlog.length)
       throw new Error("backlog is not empty");
+    this.backlog = new Array(0);
+    this.seenlog.clear();
     return this.program;
   }
 
@@ -689,9 +694,14 @@ export class Parser extends DiagnosticEmitter {
       }
       let path: string | null = null;
       if (tn.skip(Token.FROM)) {
-        if (tn.skip(Token.STRINGLITERAL))
+        if (tn.skip(Token.STRINGLITERAL)) {
           path = tn.readString();
-        else {
+          const resolvedPath: string = resolvePath(normalizePath(path), tn.source.normalizedPath);
+          if (!this.seenlog.has(resolvedPath)) {
+            this.backlog.push(resolvedPath);
+            this.seenlog.add(resolvedPath);
+          }
+        } else {
           this.error(DiagnosticCode.String_literal_expected, tn.range());
           return null;
         }
@@ -743,6 +753,11 @@ export class Parser extends DiagnosticEmitter {
       if (tn.skip(Token.FROM)) {
         if (tn.skip(Token.STRINGLITERAL)) {
           const path: string = tn.readString();
+          const resolvedPath: string = resolvePath(normalizePath(path), tn.source.normalizedPath);
+          if (!this.seenlog.has(resolvedPath)) {
+            this.backlog.push(resolvedPath);
+            this.seenlog.add(resolvedPath);
+          }
           const ret: ImportStatement = Statement.createImport(members, path, Range.join(startRange, tn.range()));
           tn.skip(Token.SEMICOLON);
           return ret;
diff --git a/src/program.ts b/src/program.ts
index d3f8fa4d..63550126 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -2,18 +2,21 @@ import { Target } from "./compiler";
 import { DiagnosticCode, DiagnosticMessage, DiagnosticEmitter } from "./diagnostics";
 import { Source, Type, Class, Enum, Function, GlobalVariable, Namespace } from "./reflection";
 import { hasModifier } from "./parser";
-import { normalizePath, resolvePath } from "./util";
+import { normalizePath, resolvePath, trimExtension } from "./util";
 import {
 
   Node,
   NodeKind,
   SourceNode,
   ModifierKind,
+  IdentifierExpression,
 
   ClassDeclaration,
   DeclarationStatement,
   EnumDeclaration,
   EnumValueDeclaration,
+  ExportMember,
+  ExportStatement,
   FieldDeclaration,
   FunctionDeclaration,
   ImportDeclaration,
@@ -27,15 +30,31 @@ import {
 
 } from "./ast";
 
+class QueuedExport {
+  importName: string;
+  member: ExportMember;
+}
+
+class QueuedImport {
+  globalName: string;
+  importName: string;
+  declaration: ImportDeclaration;
+}
+
 export class Program extends DiagnosticEmitter {
 
   sources: Source[];
   diagnosticsOffset: i32 = 0;
   target: Target = Target.WASM32;
 
+  // internal names to declarations
   names: Map<string,DeclarationStatement> = new Map();
+  // type names to types
   types: Map<string,Type> = new Map();
+  // export names to declarations (separate from internal names)
+  exports: Map<string,DeclarationStatement> = new Map();
 
+  // reflection instances
   classes: Class[] = new Array();
   enums: Enum[] = new Array();
   functions: Function[] = new Array();
@@ -51,9 +70,10 @@ export class Program extends DiagnosticEmitter {
     this.target = target;
     initializeBasicTypes(this.types, target);
 
-    const importStatements: ImportStatement[] = new Array();
+    const exportsMap: Map<string,QueuedExport> = new Map();
+    const importsQueue: QueuedImport[] = new Array();
 
-    // build a lookup map of global names to declarations
+    // build initial lookup maps of global and export names to declarations
     for (let i: i32 = 0, k: i32 = this.sources.length; i < k; ++i) {
       const source: Source = this.sources[i];
       const statements: Statement[] = source.statements;
@@ -69,13 +89,16 @@ export class Program extends DiagnosticEmitter {
             this.initializeEnum(<EnumDeclaration>statement);
             break;
 
+          case NodeKind.EXPORT:
+            this.initializeExports(<ExportStatement>statement, exportsMap);
+            break;
+
           case NodeKind.FUNCTION:
             this.initializeFunction(<FunctionDeclaration>statement);
             break;
 
           case NodeKind.IMPORT:
-            this.initializeImports(<ImportStatement>statement);
-            importStatements.push(<ImportStatement>statement);
+            this.initializeImports(<ImportStatement>statement, exportsMap, importsQueue);
             break;
 
           case NodeKind.INTERFACE:
@@ -93,26 +116,52 @@ export class Program extends DiagnosticEmitter {
       }
     }
 
-    // resolve imports to their respective declarations
-    for (let i: i32 = 0, k: i32 = importStatements.length; i < k; ++i) {
-      const statement: ImportStatement = importStatements[i];
-      const importPath: string = resolvePath(normalizePath(statement.path), statement.range.source.normalizedPath);
-      const members: ImportDeclaration[] = statement.declarations;
-      for (let j: i32 = 0, l: i32 = members.length; j < l; ++j){
-        const declaration: ImportDeclaration = members[j];
-        const importedName: string = declaration.externalIdentifier.name;
-        for (let m: i32 = 0, n: i32 = this.sources.length; m < n; ++n) {
-          const source: Source = this.sources[m];
-          if (source.path == importPath) {
-            // TODO
-          }
-        }
+    // at this point exports map should be resolvable
+    for (let [key, val] of exportsMap.entries()) {
+      const seen: Set<QueuedExport> = new Set();
+      while (exportsMap.has(val.importName)) {
+        val = <QueuedExport>exportsMap.get(val.importName);
+        if (seen.has(val))
+          break;
+        seen.add(val);
       }
+      if (this.exports.has(val.importName))
+        this.addExport(key, <DeclarationStatement>this.exports.get(val.importName));
+      else
+        this.error(DiagnosticCode.Cannot_find_name_0, val.member.externalIdentifier.range, val.importName);
+    }
+
+    // at this point imports queue should be resolvable
+    for (let i: i32 = 0, k: i32 = importsQueue.length; i < k; ++i) {
+      const queued: QueuedImport = importsQueue[i];
+      const globalName: string = queued.globalName;
+      let importName: string = queued.importName;
+      const seen: Set<QueuedExport> = new Set();
+      while (exportsMap.has(importName)) {
+        const val: QueuedExport = <QueuedExport>exportsMap.get(importName);
+        importName = val.importName;
+        if (seen.has(val))
+          break;
+        seen.add(val);
+      }
+      if (this.exports.has(importName)) {
+        if (this.names.has(globalName))
+          this.error(DiagnosticCode.Duplicate_identifier_0, queued.declaration.identifier.range, globalName);
+        else {
+          const declaration: DeclarationStatement = <DeclarationStatement>this.exports.get(importName);
+          this.names.set(globalName, declaration);
+          // TODO: also mirror (non-private) member names?
+        }
+      } else
+        this.error(DiagnosticCode.Cannot_find_name_0, queued.declaration.externalIdentifier.range, importName);
     }
   }
 
-  initializeClass(declaration: ClassDeclaration): void {
-    this.addName(declaration);
+  private initializeClass(declaration: ClassDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
+    if (hasModifier(ModifierKind.EXPORT, declaration.modifiers))
+      this.addExport(globalName, declaration);
     const members: DeclarationStatement[] = declaration.members;
     for (let j: i32 = 0, l: i32 = members.length; j < l; ++j) {
       const statement: Statement = members[j];
@@ -132,37 +181,88 @@ export class Program extends DiagnosticEmitter {
     }
   }
 
-  initializeField(declaration: FieldDeclaration): void {
-    this.addName(declaration);
+  private initializeField(declaration: FieldDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
   }
 
-  initializeEnum(declaration: EnumDeclaration): void {
-    this.addName(declaration);
+  private initializeEnum(declaration: EnumDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
+    if (hasModifier(ModifierKind.EXPORT, declaration.modifiers))
+      this.addExport(globalName, declaration);
     const members: EnumValueDeclaration[] = declaration.members;
     for (let i: i32 = 0, k: i32 = members.length; i < k; ++i)
       this.initializeEnumValue(members[i]);
   }
 
-  initializeEnumValue(declaration: EnumValueDeclaration): void {
-    this.addName(declaration);
+  private initializeEnumValue(declaration: EnumValueDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
   }
 
-  initializeFunction(declaration: FunctionDeclaration): void {
-    this.addName(declaration);
-  }
-
-  initializeImports(statement: ImportStatement): void {
-    const members: ImportDeclaration[] = statement.declarations;
+  private initializeExports(statement: ExportStatement, exportsMap: Map<string,QueuedExport>): void {
+    const members: ExportMember[] = statement.members;
+    const normalizedPath: string | null = statement.path == null ? null : normalizePath(<string>statement.path);
     for (let i: i32 = 0, k: i32 = members.length; i < k; ++i)
-      this.initializeImport(members[i]);
+      this.initializeExport(members[i], normalizedPath, exportsMap);
   }
 
-  initializeImport(declaration: ImportDeclaration): void {
-    this.addName(declaration);
+  private initializeExport(member: ExportMember, normalizedPath: string | null, exportsMap: Map<string,QueuedExport>): void {
+    const exportName: string = member.range.source.normalizedPath + "/" + member.externalIdentifier.name;
+    if (exportsMap.has(exportName))
+      this.error(DiagnosticCode.Duplicate_identifier_0, member.externalIdentifier.range, exportName);
+    else {
+      const queued: QueuedExport = new QueuedExport();
+      queued.importName = normalizedPath == null
+        ? member.range.source.normalizedPath + "/" + member.identifier.name // local
+        : (<string>normalizedPath) + "/" + member.identifier.name;          // re-export
+      queued.member = member;
+      exportsMap.set(exportName, queued);
+    }
   }
 
-  initializeInterface(declaration: InterfaceDeclaration): void {
-    this.addName(declaration);
+  private initializeFunction(declaration: FunctionDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
+    if (hasModifier(ModifierKind.EXPORT, declaration.modifiers))
+      this.addExport(globalName, declaration);
+  }
+
+  private initializeImports(statement: ImportStatement, exportsMap: Map<string,QueuedExport>, importsQueue: QueuedImport[]): void {
+    const members: ImportDeclaration[] = statement.declarations;
+    const normalizedPath: string = normalizePath(statement.path);
+    for (let i: i32 = 0, k: i32 = members.length; i < k; ++i) {
+      const declaration: ImportDeclaration = members[i];
+      this.initializeImport(declaration, normalizedPath, exportsMap, importsQueue);
+    }
+  }
+
+  private initializeImport(declaration: ImportDeclaration, normalizedPath: string, exportsMap: Map<string,QueuedExport>, importsQueue: QueuedImport[]): void {
+    const importName: string = normalizedPath + "/" + declaration.externalIdentifier.name;
+    let resolvedImportName: string = importName;
+    while (exportsMap.has(resolvedImportName))
+      resolvedImportName = (<QueuedExport>exportsMap.get(resolvedImportName)).importName;
+    const globalName: string = this.mangleName(declaration);
+    if (this.exports.has(resolvedImportName)) { // resolvable right away
+      if (this.names.has(globalName))
+        this.error(DiagnosticCode.Duplicate_identifier_0, declaration.identifier.range, globalName);
+      else
+        this.names.set(globalName, <DeclarationStatement>this.exports.get(resolvedImportName));
+    } else { // points to yet unresolved export
+      const queued: QueuedImport = new QueuedImport();
+      queued.globalName = globalName;
+      queued.importName = importName;
+      queued.declaration = declaration;
+      importsQueue.push(queued);
+    }
+  }
+
+  private initializeInterface(declaration: InterfaceDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
+    if (hasModifier(ModifierKind.EXPORT, declaration.modifiers))
+      this.addExport(globalName, declaration);
     const members: Statement[] = declaration.members;
     for (let j: i32 = 0, l: i32 = members.length; j < l; ++j) {
       const statement: Statement = members[j];
@@ -182,12 +282,16 @@ export class Program extends DiagnosticEmitter {
     }
   }
 
-  initializeMethod(declaration: MethodDeclaration): void {
-    this.addName(declaration);
+  private initializeMethod(declaration: MethodDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
   }
 
-  initializeNamespace(declaration: NamespaceDeclaration): void {
-    this.addName(declaration);
+  private initializeNamespace(declaration: NamespaceDeclaration): void {
+    const globalName: string = this.mangleName(declaration);
+    this.addName(globalName, declaration);
+    if (hasModifier(ModifierKind.EXPORT, declaration.modifiers))
+      this.addExport(globalName, declaration);
     const members: Statement[] = declaration.members;
     for (let j: i32 = 0, l: i32 = members.length; j < l; ++j) {
       const statement: Statement = members[j];
@@ -214,7 +318,7 @@ export class Program extends DiagnosticEmitter {
           break;
 
         case NodeKind.VARIABLE:
-          this.initializeVariables(<VariableStatement>statement);
+          this.initializeVariables(<VariableStatement>statement, true);
           break;
 
         default:
@@ -223,20 +327,30 @@ export class Program extends DiagnosticEmitter {
     }
   }
 
-  initializeVariables(statement: VariableStatement): void {
+  private initializeVariables(statement: VariableStatement, insideNamespace: bool = false): void {
     const declarations: VariableDeclaration[] = statement.members;
+    const isExport: bool = !insideNamespace && hasModifier(ModifierKind.EXPORT, statement.modifiers);
     for (let i: i32 = 0, k = declarations.length; i < k; ++i) {
       const declaration: VariableDeclaration = declarations[i];
-      this.addName(declaration);
+      const globalName: string = this.mangleName(declaration);
+      this.addName(globalName, declaration);
+      if (isExport)
+        this.addExport(globalName, declaration);
     }
   }
 
-  addName(declaration: DeclarationStatement): void {
-    const name: string = this.mangleName(declaration);
-    if (this.names.has(name))
-      this.error(DiagnosticCode.Duplicate_identifier_0, declaration.identifier.range, name); // recoverable
+  private addName(globalName: string, declaration: DeclarationStatement): void {
+    if (this.names.has(globalName))
+      this.error(DiagnosticCode.Duplicate_identifier_0, declaration.identifier.range, globalName); // recoverable
     else
-      this.names.set(name, declaration);
+      this.names.set(globalName, declaration);
+  }
+
+  private addExport(globalName: string, declaration: DeclarationStatement): void {
+    if (this.exports.has(globalName))
+      this.error(DiagnosticCode.Duplicate_identifier_0, declaration.identifier.range, globalName); // recoverable
+    else
+      this.exports.set(globalName, declaration);
   }
 
   mangleName(declaration: DeclarationStatement): string {
@@ -246,7 +360,7 @@ export class Program extends DiagnosticEmitter {
       switch (parent.kind) {
 
         case NodeKind.SOURCE:
-          return (<SourceNode>parent).path + "/" + name;
+          return (<Source>parent).normalizedPath + "/" + name;
 
         case NodeKind.CLASS: {
           if (
@@ -314,12 +428,12 @@ function initializeBasicTypes(types: Map<string,Type>, target: Target) {
   types.set("i16", Type.i16);
   types.set("i32", Type.i32);
   types.set("i64", Type.i64);
-  types.set("isize", target == Target.WASM32 ? Type.isize32 : Type.isize64);
+  types.set("isize", target == Target.WASM64 ? Type.isize64 : Type.isize32);
   types.set("u8", Type.u8);
   types.set("u16", Type.u16);
   types.set("u32", Type.u32);
   types.set("u64", Type.u64);
-  types.set("usize", target == Target.WASM32 ? Type.usize32 : Type.usize64);
+  types.set("usize", target == Target.WASM64 ? Type.usize64 : Type.usize32);
   types.set("bool", Type.bool);
   types.set("void", Type.void);
 }
diff --git a/src/reflection.ts b/src/reflection.ts
index 6e355948..2bead97a 100644
--- a/src/reflection.ts
+++ b/src/reflection.ts
@@ -42,7 +42,7 @@ import {
 import { DiagnosticMessage } from "./diagnostics";
 import { Token, Tokenizer, Range } from "./tokenizer";
 import { hasModifier } from "./parser";
-import { normalizePath } from "./util";
+import { normalizePath, trimExtension } from "./util";
 
 export abstract class Base {
 
@@ -146,7 +146,7 @@ export class Type extends Base {
 export class Source extends SourceNode {
 
   text: string;
-  tokenizer: Tokenizer | null;
+  tokenizer: Tokenizer | null = null;
   statements: Statement[];
   isEntry: bool;
   normalizedPath: string;
@@ -158,7 +158,7 @@ export class Source extends SourceNode {
     this.text = text;
     this.statements = new Array();
     this.isEntry = isEntry;
-    this.normalizedPath = normalizePath(path);
+    this.normalizedPath = normalizePath(trimExtension(path));
   }
 
   get isDeclaration(): bool { return !this.isEntry && this.path.endsWith(".d.ts"); }
diff --git a/src/tsconfig.json b/src/tsconfig.json
index 33989936..841b22d2 100644
--- a/src/tsconfig.json
+++ b/src/tsconfig.json
@@ -9,6 +9,7 @@
     "types": [
       "node"
     ],
+    "downlevelIteration": true,
     "strictNullChecks": true,
     "alwaysStrict": true,
     "outDir": "../out"
diff --git a/src/util.ts b/src/util.ts
index ceb3efa9..042008ff 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -226,3 +226,10 @@ export function dirname(normalizedPath: string, separator: CharCode = CharCode.S
 export function resolvePath(normalizedPath: string, normalizedOrigin: string, separator: CharCode = CharCode.SLASH): string {
   return normalizePath(dirname(normalizedOrigin, separator) + String.fromCharCode(separator) + normalizedPath);
 }
+
+export function trimExtension(path: string): string {
+  const len: i32 = path.length;
+  if (len > 3 && path.charCodeAt(len - 3) == CharCode.DOT && (path.charCodeAt(len - 2) == CharCode.t || path.charCodeAt(len - 2) == CharCode.a) && path.charCodeAt(len - 1) == CharCode.s)
+    return path.substring(0, len - 3);
+  return path;
+}
diff --git a/src/util/i64.ts b/src/util/i64.ts
index f8a31509..ab61b573 100644
--- a/src/util/i64.ts
+++ b/src/util/i64.ts
@@ -31,6 +31,10 @@ export class I64 {
     return this.lo == 0 && this.hi == 0;
   }
 
+  get isOne(): bool {
+    return this.lo == 1 && this.hi == 0;
+  }
+
   get isPositive(): bool {
     return this.hi >= 0;
   }
@@ -47,6 +51,10 @@ export class I64 {
     return (this.lo & 1) == 0;
   }
 
+  get fitsInI32(): bool {
+    return this.hi == 0 || (this.hi == -1 && this.lo < 0);
+  }
+
   toI32(): i32 {
     return this.lo;
   }
diff --git a/tests/compiler.ts b/tests/compiler.ts
new file mode 100644
index 00000000..bb1ec3f3
--- /dev/null
+++ b/tests/compiler.ts
@@ -0,0 +1,37 @@
+import "../src/glue/js";
+import { Compiler } from "../src/compiler";
+import { Parser } from "../src/parser";
+
+const files: Map<string,string> = new Map([
+  ["main", `import { Test } from "./a"; export { TestAlias } from "./d";`],
+  ["a", `export { Test } from "./b";`],
+  ["b", `export { Test } from "./c";`],
+  ["c", `export enum Test { ONE = 1 }`],
+  ["d", `export { Test as TestAlias } from "./b";`]
+]);
+
+const parser = new Parser();
+parser.parseFile(<string>files.get("main"), "main", true);
+do {
+  let nextFile = parser.nextFile();
+  if (!nextFile)
+    break;
+  if (!files.has(nextFile))
+    throw new Error("file not found: " + nextFile);
+  parser.parseFile(<string>files.get(nextFile), nextFile, false);
+} while(true);
+const program = parser.finish();
+const compiler = new Compiler(program);
+const module = compiler.compile();
+
+console.log("names", program.names);
+console.log("exports", program.exports);
+
+// module.optimize();
+// module.validate(); // global initializers can't use i32.add etc. yet
+/* _BinaryenModulePrint(module.ref);
+
+console.log("--- statements ---");
+compiler.statements.forEach(stmt => {
+  _BinaryenExpressionPrint(stmt);
+}); */
\ No newline at end of file