Abstract Syntax Tree

Parsing a file using the Ethers ASM Dialect will generate an Abstract Syntax Tree. The root node will always be a ScopeNode whose name is _.

To parse a file into an Abstract Syntax tree, use the parse function.

Types

Location

offset number

The offset into the source code to the start of this node.

length number

The length of characters in the source code to the end of this node.

source string

The source code of this node.

Nodes

@TODO: Place a diagram here showing the hierarchy

Node

node.tag string

A unique tag for this node for the lifetime of the process.

node.location Location

The source code and location within the source code that this node represents.

ValueNode inherits Node

A ValueNode is a node which may manipulate the stack.

LiteralNode inherits ValueNode

literalNode.value string

The literal value of this node, which may be a DataHexString or string of a decimal number.

literalNode.verbatim boolean

This is true in a DataNode context, since in that case the value should be taken verbatim and no PUSH operation shoud be added, otherwise false.

PopNode inherits ValueNode

A PopNode is used to store a place-holder for an implicit pop from the stack. It represents the code for an implicit place-holder (i.e. $$) or an explicit place-holder (e.g. $1), which indicates the expect stack position to consume.

literalNode.index number

The index this PopNode is representing. For an implicit place-holder this is 0.

LinkNode inherits ValueNode

A LinkNode represents a link to another Node's data, for example $foo or #bar.

linkNode.label string

Te name of the target node.

linkNode.type "offset" | "length"

Whether this node is for an offset or a length value of the target node.

OpcodeNode inherits ValueNode

opcodeNode.opcode Opcode

The opcode for this Node.

opcodeNode.operands Array< ValueNode >

A list of all operands passed into this Node.

EvaluationNode inherits ValueNode

An EvaluationNode is used to execute code and insert the results but does not generate any output assembly, using the {{! code here }} syntax.

literalNode.verbatim boolean

This is true in a DataNode context, since in that case the value should be taken verbatim and no PUSH operation shoud be added, otherwise false.

evaluationNode.script string

The code to evaluate and produce the result to use as a literal.

ExecutionNode inherits Node

An ExecutionNode is used to execute code but does not generate any output assembly, using the {{! code here }} syntax.

evaluationNode.script string

The code to execute. Any result is ignored.

LabelledNode inherits Node

A LabelledNode is used for any Node that has a name, and can therefore be targetted by a LinkNode.

labelledNode.name string

The name of this node.

LabelNode inherits LabelledNode

A LabelNode is used as a place to JUMP to by referencing it name, using @myLabel:. A JUMPDEST is automatically inserted at the bytecode offset.

DataNode inherits LabelledNode

A DataNode allows for data to be inserted directly into the output assembly, using @myData[ ... ]. The data is padded if needed to ensure values that would otherwise be regarded as a PUSH value does not impact anything past the data.

dataNode.data Array< ValueNode >

The child nodes, which each represent a verbatim piece of data in insert.

ScopeNode inherits LabelledNode

A ScopeNode allows a new frame of reference that all LinkNode's will use when resolving offset locations, using @myScope{ ... }.

scopeNode.statements Array< Node >

The list of child nodes for this scope.