Moved Abi Encoder into utils package

5 files changed, 1395 insertions, 0 deletions

diff --git a/packages/utils/src/abi_encoder/calldata.ts b/packages/utils/src/abi_encoder/calldata.ts
new file mode 100644
index 000000000..32278e5c5
--- /dev/null
+++ b/packages/utils/src/abi_encoder/calldata.ts
@@ -0,0 +1,520 @@
+import ethUtil = require('ethereumjs-util');
+import CommunicationChatBubbleOutline from 'material-ui/SvgIcon';
+var _ = require('lodash');
+
+export interface DecodingRules {
+    structsAsObjects: boolean;
+}
+
+export interface EncodingRules {
+    optimize?: boolean;
+    annotate?: boolean;
+}
+
+export abstract class CalldataBlock {
+    private name: string;
+    private signature: string;
+    private offsetInBytes: number;
+    private headerSizeInBytes: number;
+    private bodySizeInBytes: number;
+    private relocatable: boolean;
+    private parentName: string;
+
+    constructor(name: string, signature: string, parentName: string, /*offsetInBytes: number,*/ headerSizeInBytes: number, bodySizeInBytes: number, relocatable: boolean) {
+        this.name = name;
+        this.signature = signature;
+        this.parentName = parentName;
+        this.offsetInBytes = 0;
+        this.headerSizeInBytes = headerSizeInBytes;
+        this.bodySizeInBytes = bodySizeInBytes;
+        this.relocatable = relocatable;
+    }
+
+    protected setHeaderSize(headerSizeInBytes: number) {
+        this.headerSizeInBytes = headerSizeInBytes;
+    }
+
+    protected setBodySize(bodySizeInBytes: number) {
+        this.bodySizeInBytes = bodySizeInBytes;
+    }
+
+    protected setName(name: string) {
+        this.name = name;
+    }
+
+    public getName(): string {
+        return this.name;
+    }
+
+    public getParentName(): string {
+        return this.parentName;
+    }
+
+    public getSignature(): string {
+        return this.signature;
+    }
+
+    public isRelocatable(): boolean {
+        return this.relocatable;
+    }
+
+    public getHeaderSizeInBytes(): number {
+        return this.headerSizeInBytes;
+    }
+
+    public getBodySizeInBytes(): number {
+        return this.bodySizeInBytes;
+    }
+
+    public getSizeInBytes(): number {
+        return this.headerSizeInBytes + this.bodySizeInBytes;
+    }
+
+    public getOffsetInBytes(): number {
+        return this.offsetInBytes;
+    }
+
+    public setOffset(offsetInBytes: number) {
+        this.offsetInBytes = offsetInBytes;
+    }
+
+    public computeHash(): Buffer {
+        const rawData = this.getRawData();
+        const hash = ethUtil.sha3(rawData);
+        return hash;
+    }
+
+    public abstract toBuffer(): Buffer;
+    public abstract getRawData(): Buffer;
+}
+
+export class PayloadCalldataBlock extends CalldataBlock {
+    private payload: Buffer;
+
+    constructor(name: string, signature: string, parentName: string, /*offsetInBytes: number,*/ relocatable: boolean, payload: Buffer) {
+        const headerSizeInBytes = 0;
+        const bodySizeInBytes = payload.byteLength;
+        super(name, signature, parentName, headerSizeInBytes, bodySizeInBytes, relocatable);
+        this.payload = payload;
+    }
+
+    public toBuffer(): Buffer {
+        return this.payload;
+    }
+
+    public getRawData(): Buffer {
+        return this.payload;
+    }
+}
+
+export class DependentCalldataBlock extends CalldataBlock {
+    public static DEPENDENT_PAYLOAD_SIZE_IN_BYTES = 32;
+    public static RAW_DATA_START = new Buffer('<');
+    public static RAW_DATA_END = new Buffer('>');
+    private parent: CalldataBlock;
+    private dependency: CalldataBlock;
+    private aliasFor: CalldataBlock | undefined;
+
+    constructor(name: string, signature: string, parentName: string, relocatable: boolean, dependency: CalldataBlock, parent: CalldataBlock) {
+        const headerSizeInBytes = 0;
+        const bodySizeInBytes = DependentCalldataBlock.DEPENDENT_PAYLOAD_SIZE_IN_BYTES;
+        super(name, signature, parentName, headerSizeInBytes, bodySizeInBytes, relocatable);
+        this.parent = parent;
+        this.dependency = dependency;
+        this.aliasFor = undefined;
+    }
+
+    public toBuffer(): Buffer {
+        const destinationOffset = (this.aliasFor !== undefined) ? this.aliasFor.getOffsetInBytes() : this.dependency.getOffsetInBytes();
+        const parentOffset = this.parent.getOffsetInBytes();
+        const parentHeaderSize = this.parent.getHeaderSizeInBytes();
+        const pointer: number = destinationOffset - (parentOffset + parentHeaderSize);
+        const pointerBuf = ethUtil.toBuffer(`0x${pointer.toString(16)}`);
+        const evmWordWidthInBytes = 32;
+        const pointerBufPadded = ethUtil.setLengthLeft(pointerBuf, evmWordWidthInBytes);
+        return pointerBufPadded;
+    }
+
+    public getDependency(): CalldataBlock {
+        return this.dependency;
+    }
+
+    public setAlias(block: CalldataBlock) {
+        this.aliasFor = block;
+        this.setName(`${this.getName()} (alias for ${block.getName()})`);
+    }
+
+    public getAlias(): CalldataBlock | undefined {
+        return this.aliasFor;
+    }
+
+    public getRawData(): Buffer {
+        const dependencyRawData = this.dependency.getRawData();
+        const rawDataComponents: Buffer[] = [];
+        rawDataComponents.push(DependentCalldataBlock.RAW_DATA_START);
+        rawDataComponents.push(dependencyRawData);
+        rawDataComponents.push(DependentCalldataBlock.RAW_DATA_END);
+        const rawData = Buffer.concat(rawDataComponents);
+        return rawData;
+    }
+}
+
+export class MemberCalldataBlock extends CalldataBlock {
+    private static DEPENDENT_PAYLOAD_SIZE_IN_BYTES = 32;
+    private header: Buffer | undefined;
+    private members: CalldataBlock[];
+    private contiguous: boolean;
+
+    constructor(name: string, signature: string, parentName: string, relocatable: boolean, contiguous: boolean) {
+        super(name, signature, parentName, 0, 0, relocatable);
+        this.members = [];
+        this.header = undefined;
+        this.contiguous = contiguous;
+    }
+
+    public getRawData(): Buffer {
+        const rawDataComponents: Buffer[] = [];
+        if (this.header !== undefined) {
+            rawDataComponents.push(this.header);
+        }
+        _.each(this.members, (member: CalldataBlock) => {
+            const memberBuffer = member.getRawData();
+            rawDataComponents.push(memberBuffer);
+        });
+
+        const rawData = Buffer.concat(rawDataComponents);
+        return rawData;
+    }
+
+    public setMembers(members: CalldataBlock[]) {
+        let bodySizeInBytes = 0;
+        _.each(members, (member: CalldataBlock) => {
+            bodySizeInBytes += member.getSizeInBytes();
+        });
+        this.members = members;
+        this.setBodySize(0);
+    }
+
+    public isContiguous(): boolean {
+        return true;
+    }
+
+    public setHeader(header: Buffer) {
+        this.setHeaderSize(header.byteLength);
+        this.header = header;
+    }
+
+    public toBuffer(): Buffer {
+        if (this.header !== undefined) return this.header;
+        return new Buffer('');
+    }
+
+    public getMembers(): CalldataBlock[] {
+        return this.members;
+    }
+}
+
+class Queue<T> {
+    private store: T[] = [];
+    push(val: T) {
+        this.store.push(val);
+    }
+    pushFront(val: T) {
+        this.store.unshift(val);
+    }
+    pop(): T | undefined {
+        return this.store.shift();
+    }
+    popBack(): T | undefined {
+        if (this.store.length === 0) return undefined;
+        const backElement = this.store.splice(-1, 1)[0];
+        return backElement;
+    }
+    merge(q: Queue<T>) {
+        this.store = this.store.concat(q.store);
+    }
+    mergeFront(q: Queue<T>) {
+        this.store = q.store.concat(this.store);
+    }
+    getStore(): T[] {
+        return this.store;
+    }
+    peek(): T | undefined {
+        return this.store.length >= 0 ? this.store[0] : undefined;
+    }
+}
+
+export class Calldata {
+    private selector: string;
+    private rules: EncodingRules;
+    private sizeInBytes: number;
+    private root: MemberCalldataBlock | undefined;
+
+    constructor(rules: EncodingRules) {
+        this.selector = '';
+        this.rules = rules;
+        this.sizeInBytes = 0;
+        this.root = undefined;
+    }
+
+    private createQueue(memberBlock: MemberCalldataBlock): Queue<CalldataBlock> {
+        const blockQueue = new Queue<CalldataBlock>();
+        _.eachRight(memberBlock.getMembers(), (member: CalldataBlock) => {
+            if (member instanceof MemberCalldataBlock) {
+                blockQueue.mergeFront(this.createQueue(member));
+            } else {
+                blockQueue.pushFront(member);
+            }
+        });
+
+        // Children
+        _.each(memberBlock.getMembers(), (member: CalldataBlock) => {
+            if (member instanceof DependentCalldataBlock && member.getAlias() === undefined) {
+                let dependency = member.getDependency();
+                if (dependency instanceof MemberCalldataBlock) {
+                    blockQueue.merge(this.createQueue(dependency));
+                } else {
+                    blockQueue.push(dependency);
+                }
+            }
+        });
+
+        blockQueue.pushFront(memberBlock);
+        return blockQueue;
+    }
+
+    private generateAnnotatedHexString(): string {
+        let hexValue = `${this.selector}`;
+        if (this.root === undefined) {
+            throw new Error('expected root');
+        }
+
+        const valueQueue = this.createQueue(this.root);
+
+        let block: CalldataBlock | undefined;
+        let offset = 0;
+        const functionBlock = valueQueue.peek();
+        let functionName: string = functionBlock === undefined ? '' : functionBlock.getName();
+        while ((block = valueQueue.pop()) !== undefined) {
+            // Set f
+
+            // Process each block 1 word at a time
+            const size = block.getSizeInBytes();
+            const name = block.getName();
+            const parentName = block.getParentName();
+
+            //const ancestrialNamesOffset = name.startsWith('ptr<') ? 4 : 0;
+            //const parentOffset = name.lastIndexOf(parentName);
+            const prettyName = name.replace(`${parentName}.`, '').replace(`${functionName}.`, '');//.replace(`${parentName}[`, '[');
+            const signature = block.getSignature();
+
+            // Current offset
+            let offsetStr = '';
+
+            // If this block is empty then it's a newline
+            let value = '';
+            let nameStr = '';
+            let line = '';
+            if (size === 0) {
+                offsetStr = ' '.repeat(10);
+                value = ' '.repeat(74);
+                nameStr = `### ${prettyName.padEnd(80)}`;
+                line = `\n${offsetStr}${value}${nameStr}`;
+            } else {
+                offsetStr = `0x${offset.toString(16)}`.padEnd(10, ' ');
+                value = ethUtil.stripHexPrefix(ethUtil.bufferToHex(block.toBuffer().slice(0, 32))).padEnd(74);
+                if (block instanceof MemberCalldataBlock) {
+                    nameStr = `### ${prettyName.padEnd(80)}`;
+                    line = `\n${offsetStr}${value}${nameStr}`;
+                } else {
+                    nameStr = `    ${prettyName.padEnd(80)}`;
+                    line = `${offsetStr}${value}${nameStr}`;
+                }
+            }
+
+            for (let j = 32; j < size; j += 32) {
+                offsetStr = `0x${(offset + j).toString(16)}`.padEnd(10, ' ');
+                value = ethUtil.stripHexPrefix(ethUtil.bufferToHex(block.toBuffer().slice(j, j + 32))).padEnd(74);
+                nameStr = ' '.repeat(40);
+
+                line = `${line}\n${offsetStr}${value}${nameStr}`;
+            }
+
+            // Append to hex value
+            hexValue = `${hexValue}\n${line}`;
+            offset += size;
+        }
+
+        return hexValue;
+    }
+
+    private generateCondensedHexString(): string {
+        let selectorBuffer = ethUtil.toBuffer(this.selector);
+        if (this.root === undefined) {
+            throw new Error('expected root');
+        }
+
+        const valueQueue = this.createQueue(this.root);
+        const valueBufs: Buffer[] = [selectorBuffer];
+        let block: CalldataBlock | undefined;
+        while ((block = valueQueue.pop()) !== undefined) {
+            valueBufs.push(block.toBuffer());
+        }
+
+        const combinedBuffers = Buffer.concat(valueBufs);
+        const hexValue = ethUtil.bufferToHex(combinedBuffers);
+        return hexValue;
+    }
+
+    public optimize() {
+        if (this.root === undefined) {
+            throw new Error('expected root');
+        }
+
+        const blocksByHash: { [key: string]: CalldataBlock } = {};
+
+        // 1. Create a queue of subtrees by hash
+        // Note that they are ordered the same as 
+        const subtreeQueue = this.createQueue(this.root);
+        let block: CalldataBlock | undefined;
+        while ((block = subtreeQueue.popBack()) !== undefined) {
+            if (block instanceof DependentCalldataBlock) {
+                const blockHashBuf = block.getDependency().computeHash();
+                const blockHash = ethUtil.bufferToHex(blockHashBuf);
+                if (blockHash in blocksByHash) {
+                    const blockWithSameHash = blocksByHash[blockHash];
+                    if (blockWithSameHash !== block.getDependency()) {
+                        block.setAlias(blockWithSameHash);
+                    }
+                }
+                continue;
+            }
+
+            const blockHashBuf = block.computeHash();
+            const blockHash = ethUtil.bufferToHex(blockHashBuf);
+            if (blockHash in blocksByHash === false) {
+                blocksByHash[blockHash] = block;
+            }
+        }
+    }
+
+    public toHexString(): string {
+        if (this.root === undefined) {
+            throw new Error('expected root');
+        }
+
+        if (this.rules.optimize) this.optimize();
+
+        const offsetQueue = this.createQueue(this.root);
+        let block: CalldataBlock | undefined;
+        let offset = 0;
+        while ((block = offsetQueue.pop()) !== undefined) {
+            block.setOffset(offset);
+            offset += block.getSizeInBytes();
+        }
+
+        const hexValue = this.rules.annotate ? this.generateAnnotatedHexString() : this.generateCondensedHexString();
+        return hexValue;
+    }
+
+    public getSelectorHex(): string {
+        return this.selector;
+    }
+
+    public getSizeInBytes(): number {
+        return this.sizeInBytes;
+    }
+
+    public toAnnotatedString(): string {
+        return "";
+    }
+
+    public setRoot(block: MemberCalldataBlock) {
+        this.root = block;
+        this.sizeInBytes += block.getSizeInBytes();
+    }
+
+    public setSelector(selector: string) {
+        // Ensure we have a 0x prefix
+        if (selector.startsWith('0x')) {
+            this.selector = selector;
+        } else {
+            this.selector = `$0x${selector}`;
+        }
+
+        // The selector must be 10 characters: '0x' followed by 4 bytes (two hex chars per byte)
+        if (this.selector.length !== 10) {
+            throw new Error(`Invalid selector '${this.selector}'`);
+        }
+        this.sizeInBytes += 8;
+    }
+}
+
+export class RawCalldata {
+    private value: Buffer;
+    private offset: number; // tracks current offset into raw calldata; used for parsing
+    private selector: string;
+    private scopes: Queue<number>;
+
+    constructor(value: string | Buffer) {
+        if (typeof value === 'string' && !value.startsWith('0x')) {
+            throw new Error(`Expected raw calldata to start with '0x'`);
+        }
+        const valueBuf = ethUtil.toBuffer(value);
+        this.selector = ethUtil.bufferToHex(valueBuf.slice(0, 4));
+        this.value = valueBuf.slice(4); // disregard selector
+        this.offset = 0;
+        this.scopes = new Queue<number>();
+        this.scopes.push(0);
+    }
+
+    public popBytes(lengthInBytes: number): Buffer {
+        const value = this.value.slice(this.offset, this.offset + lengthInBytes);
+        this.setOffset(this.offset + lengthInBytes);
+        return value;
+    }
+
+    public popWord(): Buffer {
+        const wordInBytes = 32;
+        return this.popBytes(wordInBytes);
+    }
+
+    public popWords(length: number): Buffer {
+        const wordInBytes = 32;
+        return this.popBytes(length * wordInBytes);
+    }
+
+    public readBytes(from: number, to: number): Buffer {
+        const value = this.value.slice(from, to);
+        return value;
+    }
+
+    public setOffset(offsetInBytes: number) {
+        this.offset = offsetInBytes;
+    }
+
+    public startScope() {
+        this.scopes.pushFront(this.offset);
+    }
+
+    public endScope() {
+        this.scopes.pop();
+    }
+
+    public getOffset(): number {
+        return this.offset;
+    }
+
+    public toAbsoluteOffset(relativeOffset: number) {
+        const scopeOffset = this.scopes.peek();
+        if (scopeOffset === undefined) {
+            throw new Error(`Tried to access undefined scope.`);
+        }
+        const absoluteOffset = relativeOffset + scopeOffset;
+        return absoluteOffset;
+    }
+
+    public getSelector(): string {
+        return this.selector;
+    }
+}
\ No newline at end of file
diff --git a/packages/utils/src/abi_encoder/data_type.ts b/packages/utils/src/abi_encoder/data_type.ts
new file mode 100644
index 000000000..3b4028abd
--- /dev/null
+++ b/packages/utils/src/abi_encoder/data_type.ts
@@ -0,0 +1,322 @@
+import { RawCalldata, Calldata, CalldataBlock, PayloadCalldataBlock, DependentCalldataBlock, MemberCalldataBlock } from "./calldata";
+import { MethodAbi, DataItem } from 'ethereum-types';
+import { DecodingRules, EncodingRules } from './calldata';
+import { BigNumber } from '../configured_bignumber';
+import ethUtil = require('ethereumjs-util');
+var _ = require('lodash');
+
+export interface DataTypeFactory {
+    create: (dataItem: DataItem, parentDataType: DataType) => DataType;
+    mapDataItemToDataType: (dataItem: DataItem) => DataType;
+}
+
+export abstract class DataType {
+    private static DEFAULT_ENCODING_RULES = { optimize: false, annotate: false } as EncodingRules;
+    private static DEFAULT_DECODING_RULES = { structsAsObjects: false } as DecodingRules;
+
+    private dataItem: DataItem;
+    private factory: DataTypeFactory;
+
+    constructor(dataItem: DataItem, factory: DataTypeFactory) {
+        this.dataItem = dataItem;
+        this.factory = factory;
+    }
+
+    public getDataItem(): DataItem {
+        return this.dataItem;
+    }
+
+    public getFactory(): DataTypeFactory {
+        return this.factory;
+    }
+
+    public encode(value: any, rules?: EncodingRules, selector?: string): string {
+        const rules_ = rules ? rules : DataType.DEFAULT_ENCODING_RULES;
+        const calldata = new Calldata(rules_);
+        if (selector) calldata.setSelector(selector);
+        const block = this.generateCalldataBlock(value);
+        calldata.setRoot(block as MemberCalldataBlock); // @TODO CHANGE
+        const calldataHex = calldata.toHexString();
+        return calldataHex;
+    }
+
+    public decode(calldata: string, rules?: DecodingRules): any {
+        const rawCalldata = new RawCalldata(calldata);
+        const rules_ = rules ? rules : DataType.DEFAULT_DECODING_RULES;
+        const value = this.generateValue(rawCalldata, rules_);
+        return value;
+    }
+
+    public abstract generateCalldataBlock(value: any, parentBlock?: CalldataBlock): CalldataBlock;
+    public abstract generateValue(calldata: RawCalldata, rules: DecodingRules): any;
+    public abstract getSignature(): string;
+    public abstract isStatic(): boolean;
+}
+
+export abstract class PayloadDataType extends DataType {
+    protected hasConstantSize: boolean;
+
+    public constructor(dataItem: DataItem, factory: DataTypeFactory, hasConstantSize: boolean) {
+        super(dataItem, factory);
+        this.hasConstantSize = hasConstantSize;
+    }
+
+    public generateCalldataBlock(value: any, parentBlock?: CalldataBlock): PayloadCalldataBlock {
+        const encodedValue = this.encodeValue(value);
+        const name = this.getDataItem().name;
+        const signature = this.getSignature();
+        const parentName = parentBlock === undefined ? '' : parentBlock.getName();
+        const relocatable = false;
+        const block = new PayloadCalldataBlock(name, signature, parentName, /*offsetInBytes,*/ relocatable, encodedValue);
+        return block;
+    }
+
+    public generateValue(calldata: RawCalldata, rules: DecodingRules): any {
+        const value = this.decodeValue(calldata);
+        return value;
+    }
+
+    public isStatic(): boolean {
+        // If a payload has a constant size then it's static
+        return this.hasConstantSize;
+    }
+
+    public abstract encodeValue(value: any): Buffer;
+    public abstract decodeValue(calldata: RawCalldata): any;
+}
+
+export abstract class DependentDataType extends DataType {
+    protected dependency: DataType;
+    protected parent: DataType;
+
+    public constructor(dataItem: DataItem, factory: DataTypeFactory, dependency: DataType, parent: DataType) {
+        super(dataItem, factory);
+        this.dependency = dependency;
+        this.parent = parent;
+    }
+
+    public generateCalldataBlock(value: any, parentBlock?: CalldataBlock): DependentCalldataBlock {
+        if (parentBlock === undefined) {
+            throw new Error(`DependentDataType requires a parent block to generate its block`);
+        }
+        const dependencyBlock = this.dependency.generateCalldataBlock(value, parentBlock);
+        const name = this.getDataItem().name;
+        const signature = this.getSignature();
+        const parentName = parentBlock === undefined ? '' : parentBlock.getName();
+        const relocatable = false;
+        const block = new DependentCalldataBlock(name, signature, parentName, relocatable, dependencyBlock, parentBlock);
+        return block;
+    }
+
+    public generateValue(calldata: RawCalldata, rules: DecodingRules): any {
+        const destinationOffsetBuf = calldata.popWord();
+        const currentOffset = calldata.getOffset();
+        const destinationOffsetRelative = parseInt(ethUtil.bufferToHex(destinationOffsetBuf), 16);
+        const destinationOffsetAbsolute = calldata.toAbsoluteOffset(destinationOffsetRelative);
+        calldata.setOffset(destinationOffsetAbsolute);
+        const value = this.dependency.generateValue(calldata, rules);
+        calldata.setOffset(currentOffset);
+        return value;
+    }
+
+    public isStatic(): boolean {
+        return true;
+    }
+}
+
+export interface MemberMap {
+    [key: string]: number;
+}
+
+export abstract class MemberDataType extends DataType {
+    private memberMap: MemberMap;
+    private members: DataType[];
+    private isArray: boolean;
+    protected arrayLength: number | undefined;
+    protected arrayElementType: string | undefined;
+
+
+    public constructor(dataItem: DataItem, factory: DataTypeFactory, isArray: boolean = false, arrayLength?: number, arrayElementType?: string) {
+        super(dataItem, factory);
+        this.memberMap = {};
+        this.members = [];
+        this.isArray = isArray;
+        this.arrayLength = arrayLength;
+        this.arrayElementType = arrayElementType;
+        if (isArray && arrayLength !== undefined) {
+            [this.members, this.memberMap] = this.createMembersWithLength(dataItem, arrayLength);
+        } else if (!isArray) {
+            [this.members, this.memberMap] = this.createMembersWithKeys(dataItem);
+        }
+    }
+
+    private createMembersWithKeys(dataItem: DataItem): [DataType[], MemberMap] {
+        // Sanity check
+        if (dataItem.components === undefined) {
+            throw new Error(`Expected components`);
+        }
+
+        let members: DataType[] = [];
+        let memberMap: MemberMap = {};
+        _.each(dataItem.components, (memberItem: DataItem) => {
+            const childDataItem = {
+                type: memberItem.type,
+                name: `${dataItem.name}.${memberItem.name}`,
+            } as DataItem;
+            const components = memberItem.components;
+            if (components !== undefined) {
+                childDataItem.components = components;
+            }
+            const child = this.getFactory().create(childDataItem, this);
+            memberMap[memberItem.name] = members.length;
+            members.push(child);
+        });
+
+        return [members, memberMap];
+    }
+
+    private createMembersWithLength(dataItem: DataItem, length: number): [DataType[], MemberMap] {
+        let members: DataType[] = [];
+        let memberMap: MemberMap = {};
+        const range = _.range(length);
+        _.each(range, (idx: number) => {
+            const childDataItem = {
+                type: this.arrayElementType,
+                name: `${dataItem.name}[${idx.toString(10)}]`,
+            } as DataItem;
+            const components = dataItem.components;
+            if (components !== undefined) {
+                childDataItem.components = components;
+            }
+            const child = this.getFactory().create(childDataItem, this);
+            memberMap[idx.toString(10)] = members.length;
+            members.push(child);
+        });
+
+        return [members, memberMap];
+    }
+
+    protected generateCalldataBlockFromArray(value: any[], parentBlock?: CalldataBlock): MemberCalldataBlock {
+        // Sanity check length
+        if (this.arrayLength !== undefined && value.length !== this.arrayLength) {
+            throw new Error(
+                `Expected array of ${JSON.stringify(
+                    this.arrayLength,
+                )} elements, but got array of length ${JSON.stringify(value.length)}`,
+            );
+        }
+
+        const parentName = parentBlock === undefined ? '' : parentBlock.getName();
+        const methodBlock: MemberCalldataBlock = new MemberCalldataBlock(this.getDataItem().name, this.getSignature(), parentName, this.isStatic(), false);
+
+        let members = this.members;
+        if (this.isArray && this.arrayLength === undefined) {
+            [members,] = this.createMembersWithLength(this.getDataItem(), value.length);
+
+            const lenBuf = ethUtil.setLengthLeft(ethUtil.toBuffer(`0x${value.length.toString(16)}`), 32);
+            methodBlock.setHeader(lenBuf);
+        }
+
+        const memberBlocks: CalldataBlock[] = [];
+        _.each(members, (member: DataType, idx: number) => {
+            const block = member.generateCalldataBlock(value[idx], methodBlock);
+            memberBlocks.push(block);
+        });
+        methodBlock.setMembers(memberBlocks);
+        return methodBlock;
+    }
+
+    protected generateCalldataBlockFromObject(obj: object, parentBlock?: CalldataBlock): MemberCalldataBlock {
+        const parentName = parentBlock === undefined ? '' : parentBlock.getName();
+        const methodBlock: MemberCalldataBlock = new MemberCalldataBlock(this.getDataItem().name, this.getSignature(), parentName, this.isStatic(), false);
+        const memberBlocks: CalldataBlock[] = [];
+        let childMap = _.cloneDeep(this.memberMap);
+        _.forOwn(obj, (value: any, key: string) => {
+            if (key in childMap === false) {
+                throw new Error(`Could not assign tuple to object: unrecognized key '${key}' in object ${this.getDataItem().name}`);
+            }
+            const block = this.members[this.memberMap[key]].generateCalldataBlock(value, methodBlock);
+            memberBlocks.push(block);
+            delete childMap[key];
+        });
+
+        if (Object.keys(childMap).length !== 0) {
+            throw new Error(`Could not assign tuple to object: missing keys ${Object.keys(childMap)}`);
+        }
+
+        methodBlock.setMembers(memberBlocks);
+        return methodBlock;
+    }
+
+    public generateCalldataBlock(value: any[] | object, parentBlock?: CalldataBlock): MemberCalldataBlock {
+        const block = (value instanceof Array) ? this.generateCalldataBlockFromArray(value, parentBlock) : this.generateCalldataBlockFromObject(value, parentBlock);
+        return block;
+    }
+
+    public generateValue(calldata: RawCalldata, rules: DecodingRules): any[] | object {
+        let members = this.members;
+        if (this.isArray && this.arrayLength === undefined) {
+            const arrayLengthBuf = calldata.popWord();
+            const arrayLengthHex = ethUtil.bufferToHex(arrayLengthBuf);
+            const hexBase = 16;
+            const arrayLength = new BigNumber(arrayLengthHex, hexBase);
+
+            [members,] = this.createMembersWithLength(this.getDataItem(), arrayLength.toNumber());
+        }
+
+        calldata.startScope();
+        let value: any[] | object;
+        if (rules.structsAsObjects && !this.isArray) {
+            value = {};
+            _.each(this.memberMap, (idx: number, key: string) => {
+                const member = this.members[idx];
+                let memberValue = member.generateValue(calldata, rules);
+                (value as { [key: string]: any })[key] = memberValue;
+            });
+        } else {
+            value = [];
+            _.each(members, (member: DataType, idx: number) => {
+                let memberValue = member.generateValue(calldata, rules);
+                (value as any[]).push(memberValue);
+            });
+        }
+        calldata.endScope();
+        return value;
+    }
+
+    protected computeSignatureOfMembers(): string {
+        // Compute signature of members
+        let signature = `(`;
+        _.each(this.members, (member: DataType, i: number) => {
+            signature += member.getSignature();
+            if (i < this.members.length - 1) {
+                signature += ',';
+            }
+        });
+        signature += ')';
+        return signature;
+    }
+
+    public isStatic(): boolean {
+        /* For Tuple:
+                    const isStaticTuple = this.children.length === 0;
+                    return isStaticTuple; // @TODO: True in every case or only when dynamic data?
+
+           For Array:
+                if isLengthDefined = false then this is false
+
+                Otherwise if the first element is a Pointer then false
+        */
+
+        if (this.isArray && this.arrayLength === undefined) {
+            return false;
+        }
+
+        // Search for dependent members
+        const dependentMember = _.find(this.members, (member: DataType) => {
+            return (member instanceof DependentDataType);
+        });
+        const isStatic = (dependentMember === undefined); // static if we couldn't find a dependent member
+        return isStatic;
+    }
+}
diff --git a/packages/utils/src/abi_encoder/evm_data_types.ts b/packages/utils/src/abi_encoder/evm_data_types.ts
new file mode 100644
index 000000000..2973596fe
--- /dev/null
+++ b/packages/utils/src/abi_encoder/evm_data_types.ts
@@ -0,0 +1,550 @@
+import { DataType, DataTypeFactory, PayloadDataType, DependentDataType, MemberDataType } from './data_type';
+
+import { DecodingRules, EncodingRules } from './calldata';
+
+import { MethodAbi, DataItem } from 'ethereum-types';
+
+import ethUtil = require('ethereumjs-util');
+
+import { Calldata, RawCalldata } from './calldata';
+
+import { BigNumber } from '../configured_bignumber';
+
+var _ = require('lodash');
+
+export interface DataTypeStaticInterface {
+    matchGrammar: (type: string) => boolean;
+    encodeValue: (value: any) => Buffer;
+    decodeValue: (rawCalldata: RawCalldata) => any;
+}
+
+export class Address extends PayloadDataType {
+    private static SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
+
+    constructor(dataItem: DataItem) {
+        super(dataItem, EvmDataTypeFactory.getInstance(), Address.SIZE_KNOWN_AT_COMPILE_TIME);
+        if (!Address.matchGrammar(dataItem.type)) {
+            throw new Error(`Tried to instantiate Address with bad input: ${dataItem}`);
+        }
+    }
+
+    public getSignature(): string {
+        return 'address';
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return type === 'address';
+    }
+
+    public encodeValue(value: boolean): Buffer {
+        const evmWordWidth = 32;
+        const encodedValueBuf = ethUtil.setLengthLeft(ethUtil.toBuffer(value), evmWordWidth);
+        return encodedValueBuf;
+    }
+
+    public decodeValue(calldata: RawCalldata): string {
+        const paddedValueBuf = calldata.popWord();
+        const valueBuf = paddedValueBuf.slice(12);
+        const value = ethUtil.bufferToHex(valueBuf);
+        return value;
+    }
+}
+
+export class Bool extends PayloadDataType {
+    private static SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
+
+    constructor(dataItem: DataItem) {
+        super(dataItem, EvmDataTypeFactory.getInstance(), Bool.SIZE_KNOWN_AT_COMPILE_TIME);
+        if (!Bool.matchGrammar(dataItem.type)) {
+            throw new Error(`Tried to instantiate Bool with bad input: ${dataItem}`);
+        }
+    }
+
+    public getSignature(): string {
+        return 'bool';
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return type === 'bool';
+    }
+
+    public encodeValue(value: boolean): Buffer {
+        const evmWordWidth = 32;
+        const encodedValue = value === true ? '0x1' : '0x0';
+        const encodedValueBuf = ethUtil.setLengthLeft(ethUtil.toBuffer(encodedValue), evmWordWidth);
+        return encodedValueBuf;
+    }
+
+    public decodeValue(calldata: RawCalldata): boolean {
+        const valueBuf = calldata.popWord();
+        const valueHex = ethUtil.bufferToHex(valueBuf);
+        const valueNumber = new BigNumber(valueHex, 16);
+        let value: boolean = (valueNumber.equals(0)) ? false : true;
+        if (!(valueNumber.equals(0) || valueNumber.equals(1))) {
+            throw new Error(`Failed to decode boolean. Expected 0x0 or 0x1, got ${valueHex}`);
+        }
+        return value;
+    }
+}
+
+abstract class Number extends PayloadDataType {
+    private static SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
+    static MAX_WIDTH: number = 256;
+    static DEFAULT_WIDTH: number = Number.MAX_WIDTH;
+    width: number = Number.DEFAULT_WIDTH;
+
+    constructor(dataItem: DataItem, matcher: RegExp) {
+        super(dataItem, EvmDataTypeFactory.getInstance(), Number.SIZE_KNOWN_AT_COMPILE_TIME);
+        const matches = matcher.exec(dataItem.type);
+        if (matches === null) {
+            throw new Error(`Tried to instantiate Number with bad input: ${dataItem}`);
+        }
+        if (matches !== null && matches.length === 2 && matches[1] !== undefined) {
+            this.width = parseInt(matches[1]);
+        } else {
+            this.width = 256;
+        }
+    }
+
+    public encodeValue(value: BigNumber): Buffer {
+        if (value.greaterThan(this.getMaxValue())) {
+            throw `tried to assign value of ${value}, which exceeds max value of ${this.getMaxValue()}`;
+        } else if (value.lessThan(this.getMinValue())) {
+            throw `tried to assign value of ${value}, which exceeds min value of ${this.getMinValue()}`;
+        }
+
+        const hexBase = 16;
+        const evmWordWidth = 32;
+        let valueBuf: Buffer;
+        if (value.greaterThanOrEqualTo(0)) {
+            valueBuf = ethUtil.setLengthLeft(ethUtil.toBuffer(`0x${value.toString(hexBase)}`), evmWordWidth);
+        } else {
+            // BigNumber can't write a negative hex value, so we use twos-complement conversion to do it ourselves.
+            // Step 1/3: Convert value to positive binary string
+            const binBase = 2;
+            const valueBin = value.times(-1).toString(binBase);
+
+            // Step 2/3: Invert binary value
+            const bitsInEvmWord = 256;
+            let invertedValueBin = '1'.repeat(bitsInEvmWord - valueBin.length);
+            _.each(valueBin, (bit: string) => {
+                invertedValueBin += bit === '1' ? '0' : '1';
+            });
+            const invertedValue = new BigNumber(invertedValueBin, binBase);
+
+            // Step 3/3: Add 1 to inverted value
+            // The result is the two's-complement represent of the input value.
+            const negativeValue = invertedValue.plus(1);
+
+            // Convert the negated value to a hex string
+            valueBuf = ethUtil.setLengthLeft(
+                ethUtil.toBuffer(`0x${negativeValue.toString(hexBase)}`),
+                evmWordWidth,
+            );
+        }
+
+        return valueBuf;
+    }
+
+    public decodeValue(calldata: RawCalldata): BigNumber {
+        const paddedValueBuf = calldata.popWord();
+        const paddedValueHex = ethUtil.bufferToHex(paddedValueBuf);
+        let value = new BigNumber(paddedValueHex, 16);
+        if (this instanceof Int) {
+            // Check if we're negative
+            const binBase = 2;
+            const paddedValueBin = value.toString(binBase);
+            const valueBin = paddedValueBin.slice(paddedValueBin.length - this.width);
+            if (valueBin[0].startsWith('1')) {
+                // Negative
+                // Step 1/3: Invert binary value
+                let invertedValueBin = '';
+                _.each(valueBin, (bit: string) => {
+                    invertedValueBin += bit === '1' ? '0' : '1';
+                });
+                const invertedValue = new BigNumber(invertedValueBin, binBase);
+
+                // Step 2/3: Add 1 to inverted value
+                // The result is the two's-complement represent of the input value.
+                const positiveValue = invertedValue.plus(1);
+
+                // Step 3/3: Invert positive value
+                const negativeValue = positiveValue.times(-1);
+                value = negativeValue;
+            }
+        }
+
+        return value;
+    }
+
+    public abstract getMaxValue(): BigNumber;
+    public abstract getMinValue(): BigNumber;
+}
+
+export class Int extends Number {
+    static matcher = RegExp(
+        '^int(8|16|24|32|40|48|56|64|72|88|96|104|112|120|128|136|144|152|160|168|176|184|192|200|208|216|224|232|240|248|256){0,1}$',
+    );
+
+    constructor(dataItem: DataItem) {
+        super(dataItem, Int.matcher);
+    }
+
+    public getMaxValue(): BigNumber {
+        return new BigNumber(2).toPower(this.width - 1).sub(1);
+    }
+
+    public getMinValue(): BigNumber {
+        return new BigNumber(2).toPower(this.width - 1).times(-1);
+    }
+
+    public getSignature(): string {
+        return `int${this.width}`;
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return this.matcher.test(type);
+    }
+}
+
+export class UInt extends Number {
+    static matcher = RegExp(
+        '^uint(8|16|24|32|40|48|56|64|72|88|96|104|112|120|128|136|144|152|160|168|176|184|192|200|208|216|224|232|240|248|256){0,1}$',
+    );
+
+    constructor(dataItem: DataItem) {
+        super(dataItem, UInt.matcher);
+    }
+
+    public getMaxValue(): BigNumber {
+        return new BigNumber(2).toPower(this.width).sub(1);
+    }
+
+    public getMinValue(): BigNumber {
+        return new BigNumber(0);
+    }
+
+    public getSignature(): string {
+        return `uint${this.width}`;
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return this.matcher.test(type);
+    }
+}
+
+export class Byte extends PayloadDataType {
+    private static SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
+    static matcher = RegExp(
+        '^(byte|bytes(1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20|21|22|23|24|25|26|27|28|29|30|31|32))$',
+    );
+
+    static DEFAULT_WIDTH = 1;
+    width: number = Byte.DEFAULT_WIDTH;
+
+    constructor(dataItem: DataItem) {
+        super(dataItem, EvmDataTypeFactory.getInstance(), Byte.SIZE_KNOWN_AT_COMPILE_TIME);
+        const matches = Byte.matcher.exec(dataItem.type);
+        if (!Byte.matchGrammar(dataItem.type)) {
+            throw new Error(`Tried to instantiate Byte with bad input: ${dataItem}`);
+        }
+        if (matches !== null && matches.length === 3 && matches[2] !== undefined) {
+            this.width = parseInt(matches[2]);
+        } else {
+            this.width = Byte.DEFAULT_WIDTH;
+        }
+    }
+
+    public getSignature(): string {
+        // Note that `byte` reduces to `bytes1`
+        return `bytes${this.width}`;
+    }
+
+    public encodeValue(value: string | Buffer): Buffer {
+        // Convert value into a buffer and do bounds checking
+        const valueBuf = ethUtil.toBuffer(value);
+        if (valueBuf.byteLength > this.width) {
+            throw new Error(
+                `Tried to assign ${value} (${
+                valueBuf.byteLength
+                } bytes), which exceeds max bytes that can be stored in a ${this.getSignature()}`,
+            );
+        } else if (value.length % 2 !== 0) {
+            throw new Error(`Tried to assign ${value}, which is contains a half-byte. Use full bytes only.`);
+        }
+
+        // Store value as hex
+        const evmWordWidth = 32;
+        const paddedValue = ethUtil.setLengthRight(valueBuf, evmWordWidth);
+        return paddedValue;
+    }
+
+    public decodeValue(calldata: RawCalldata): string {
+        const paddedValueBuf = calldata.popWord();
+        const valueBuf = paddedValueBuf.slice(0, this.width);
+        const value = ethUtil.bufferToHex(valueBuf);
+        return value;
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return this.matcher.test(type);
+    }
+}
+
+export class Bytes extends PayloadDataType {
+    private static SIZE_KNOWN_AT_COMPILE_TIME: boolean = false;
+    static UNDEFINED_LENGTH = new BigNumber(-1);
+    length: BigNumber = Bytes.UNDEFINED_LENGTH;
+
+    constructor(dataItem: DataItem) {
+        super(dataItem, EvmDataTypeFactory.getInstance(), Bytes.SIZE_KNOWN_AT_COMPILE_TIME);
+        if (!Bytes.matchGrammar(dataItem.type)) {
+            throw new Error(`Tried to instantiate Bytes with bad input: ${dataItem}`);
+        }
+    }
+
+    public encodeValue(value: string | Buffer): Buffer {
+        if (typeof value === 'string' && !value.startsWith('0x')) {
+            throw new Error(`Input value must be hex (prefixed with 0x). Actual value is '${value}'`);
+        }
+        const valueBuf = ethUtil.toBuffer(value);
+        if (value.length % 2 !== 0) {
+            throw new Error(`Tried to assign ${value}, which is contains a half-byte. Use full bytes only.`);
+        }
+
+        const wordsForValue = Math.ceil(valueBuf.byteLength / 32);
+        const paddedBytesForValue = wordsForValue * 32;
+        const paddedValueBuf = ethUtil.setLengthRight(valueBuf, paddedBytesForValue);
+        const paddedLengthBuf = ethUtil.setLengthLeft(ethUtil.toBuffer(valueBuf.byteLength), 32);
+        const encodedValueBuf = Buffer.concat([paddedLengthBuf, paddedValueBuf]);
+        return encodedValueBuf;
+    }
+
+    public decodeValue(calldata: RawCalldata): string {
+        const lengthBuf = calldata.popWord();
+        const lengthHex = ethUtil.bufferToHex(lengthBuf);
+        const length = parseInt(lengthHex, 16);
+        const wordsForValue = Math.ceil(length / 32);
+        const paddedValueBuf = calldata.popWords(wordsForValue);
+        const valueBuf = paddedValueBuf.slice(0, length);
+        const decodedValue = ethUtil.bufferToHex(valueBuf);
+        return decodedValue;
+    }
+
+    public getSignature(): string {
+        return 'bytes';
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return type === 'bytes';
+    }
+}
+
+export class SolString extends PayloadDataType {
+    private static SIZE_KNOWN_AT_COMPILE_TIME: boolean = false;
+    constructor(dataItem: DataItem) {
+        super(dataItem, EvmDataTypeFactory.getInstance(), SolString.SIZE_KNOWN_AT_COMPILE_TIME);
+        if (!SolString.matchGrammar(dataItem.type)) {
+            throw new Error(`Tried to instantiate String with bad input: ${dataItem}`);
+        }
+    }
+
+    public encodeValue(value: string): Buffer {
+        const wordsForValue = Math.ceil(value.length / 32);
+        const paddedBytesForValue = wordsForValue * 32;
+        const valueBuf = ethUtil.setLengthRight(ethUtil.toBuffer(value), paddedBytesForValue);
+        const lengthBuf = ethUtil.setLengthLeft(ethUtil.toBuffer(value.length), 32);
+        const encodedValueBuf = Buffer.concat([lengthBuf, valueBuf]);
+        return encodedValueBuf;
+    }
+
+    public decodeValue(calldata: RawCalldata): string {
+        const lengthBuf = calldata.popWord();
+        const lengthHex = ethUtil.bufferToHex(lengthBuf);
+        const length = parseInt(lengthHex, 16);
+        const wordsForValue = Math.ceil(length / 32);
+        const paddedValueBuf = calldata.popWords(wordsForValue);
+        const valueBuf = paddedValueBuf.slice(0, length);
+        const value = valueBuf.toString('ascii');
+        return value;
+    }
+
+    public getSignature(): string {
+        return 'string';
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return type === 'string';
+    }
+}
+
+export class Pointer extends DependentDataType {
+
+    constructor(destDataType: DataType, parentDataType: DataType) {
+        const destDataItem = destDataType.getDataItem();
+        const dataItem = { name: `ptr<${destDataItem.name}>`, type: `ptr<${destDataItem.type}>` } as DataItem;
+        super(dataItem, EvmDataTypeFactory.getInstance(), destDataType, parentDataType);
+    }
+
+    public getSignature(): string {
+        return this.dependency.getSignature();
+    }
+}
+
+export class Tuple extends MemberDataType {
+    private tupleSignature: string;
+
+    constructor(dataItem: DataItem) {
+        super(dataItem, EvmDataTypeFactory.getInstance());
+        if (!Tuple.matchGrammar(dataItem.type)) {
+            throw new Error(`Tried to instantiate Tuple with bad input: ${dataItem}`);
+        }
+        this.tupleSignature = this.computeSignatureOfMembers();
+    }
+
+    public getSignature(): string {
+        return this.tupleSignature;
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return type === 'tuple';
+    }
+}
+
+export class SolArray extends MemberDataType {
+    static matcher = RegExp('^(.+)\\[([0-9]*)\\]$');
+    private arraySignature: string;
+    private elementType: string;
+
+    constructor(dataItem: DataItem) {
+        // Sanity check
+        const matches = SolArray.matcher.exec(dataItem.type);
+        if (matches === null || matches.length !== 3) {
+            throw new Error(`Could not parse array: ${dataItem.type}`);
+        } else if (matches[1] === undefined) {
+            throw new Error(`Could not parse array type: ${dataItem.type}`);
+        } else if (matches[2] === undefined) {
+            throw new Error(`Could not parse array length: ${dataItem.type}`);
+        }
+
+        const isArray = true;
+        const arrayElementType = matches[1];
+        const arrayLength = (matches[2] === '') ? undefined : parseInt(matches[2], 10);
+        super(dataItem, EvmDataTypeFactory.getInstance(), isArray, arrayLength, arrayElementType);
+        this.elementType = arrayElementType;
+        this.arraySignature = this.computeSignature();
+    }
+
+    private computeSignature(): string {
+        let dataItem = {
+            type: this.elementType,
+            name: 'N/A',
+        } as DataItem;
+        const components = this.getDataItem().components;
+        if (components !== undefined) {
+            dataItem.components = components;
+        }
+        const elementDataType = this.getFactory().mapDataItemToDataType(dataItem);
+        const type = elementDataType.getSignature();
+        if (this.arrayLength === undefined) {
+            return `${type}[]`;
+        } else {
+            return `${type}[${this.arrayLength}]`;
+        }
+    }
+
+    public getSignature(): string {
+        return this.arraySignature;
+    }
+
+    public static matchGrammar(type: string): boolean {
+        return this.matcher.test(type);
+    }
+}
+
+export class Method extends MemberDataType {
+    private methodSignature: string;
+    private methodSelector: string;
+
+    // TMP
+    public selector: string;
+
+    constructor(abi: MethodAbi) {
+        super({ type: 'method', name: abi.name, components: abi.inputs }, EvmDataTypeFactory.getInstance());
+        this.methodSignature = this.computeSignature();
+        this.selector = this.methodSelector = this.computeSelector();
+
+    }
+
+    private computeSignature(): string {
+        const memberSignature = this.computeSignatureOfMembers();
+        const methodSignature = `${this.getDataItem().name}${memberSignature}`;
+        return methodSignature;
+    }
+
+    private computeSelector(): string {
+        const signature = this.computeSignature();
+        const selector = ethUtil.bufferToHex(ethUtil.toBuffer(ethUtil.sha3(signature).slice(0, 4)));
+        return selector;
+    }
+
+    public encode(value: any, rules?: EncodingRules): string {
+        const calldata = super.encode(value, rules, this.selector);
+        return calldata;
+    }
+
+    public decode(calldata: string, rules?: DecodingRules): any[] | object {
+        if (!calldata.startsWith(this.selector)) {
+            throw new Error(`Tried to decode calldata, but it was missing the function selector. Expected '${this.selector}'.`);
+        }
+        const value = super.decode(calldata, rules);
+        return value;
+    }
+
+    public getSignature(): string {
+        return this.methodSignature;
+    }
+
+    public getSelector(): string {
+        return this.methodSelector;
+    }
+}
+
+export class EvmDataTypeFactory implements DataTypeFactory {
+    private static instance: DataTypeFactory;
+
+    private constructor() { }
+
+    public static getInstance(): DataTypeFactory {
+        if (!EvmDataTypeFactory.instance) {
+            EvmDataTypeFactory.instance = new EvmDataTypeFactory();
+        }
+        return EvmDataTypeFactory.instance;
+    }
+
+    public mapDataItemToDataType(dataItem: DataItem): DataType {
+        if (SolArray.matchGrammar(dataItem.type)) return new SolArray(dataItem);
+        if (Address.matchGrammar(dataItem.type)) return new Address(dataItem);
+        if (Bool.matchGrammar(dataItem.type)) return new Bool(dataItem);
+        if (Int.matchGrammar(dataItem.type)) return new Int(dataItem);
+        if (UInt.matchGrammar(dataItem.type)) return new UInt(dataItem);
+        if (Byte.matchGrammar(dataItem.type)) return new Byte(dataItem);
+        if (Tuple.matchGrammar(dataItem.type)) return new Tuple(dataItem);
+        if (Bytes.matchGrammar(dataItem.type)) return new Bytes(dataItem);
+        if (SolString.matchGrammar(dataItem.type)) return new SolString(dataItem);
+        //if (Fixed.matchGrammar(dataItem.type)) return Fixed(dataItem);
+        //if (UFixed.matchGrammar(dataItem.type)) return UFixed(dataItem);
+
+        throw new Error(`Unrecognized data type: '${dataItem.type}'`);
+    }
+
+    public create(dataItem: DataItem, parentDataType: DataType): DataType {
+        const dataType = this.mapDataItemToDataType(dataItem);
+        if (dataType.isStatic()) {
+            return dataType;
+        }
+
+        const pointer = new Pointer(dataType, parentDataType);
+        return pointer;
+    }
+}
\ No newline at end of file
diff --git a/packages/utils/src/abi_encoder/index.ts b/packages/utils/src/abi_encoder/index.ts
new file mode 100644
index 000000000..991edb8c5
--- /dev/null
+++ b/packages/utils/src/abi_encoder/index.ts
@@ -0,0 +1,2 @@
+export { EncodingRules, DecodingRules } from './calldata';
+export * from './evm_data_types';
\ No newline at end of file
diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index 0723e5788..c44530bbc 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -10,3 +10,4 @@ export { NULL_BYTES } from './constants';
 export { errorUtils } from './error_utils';
 export { fetchAsync } from './fetch_async';
 export { signTypedDataUtils } from './sign_typed_data_utils';
+export * from './abi_encoder';