evm

v0.1.14

evm v0.1.14 EVM.Stack

Operations to read / write to the EVM’s stack.

Link to this section Summary

Types

t()

Functions

length(stack)

Returns the length of the stack

peek(list)

Peeks at head of stack, returns nil if stack is empty

peek_n(stack, n)

Peeks at n elements of stack, and raises if unsufficient elements exist

pop(stack)

Pops value from stack, returning a new stack with value popped

pop_n(stack, n)

Pops multiple values off of stack, returning a new stack less that many elements

push(stack, val)

Pushes value onto stack

Link to this section Types

Link to this section Functions

Link to this function length(stack) 
length(t) :: integer

Returns the length of the stack.

Examples 

iex> EVM.Stack.length([1, 2, 3])
3

iex> EVM.Stack.length([])
0
Link to this function peek(list) 
peek(t) :: EVM.val | nil

Peeks at head of stack, returns nil if stack is empty.

Examples 

iex> EVM.Stack.peek([])
nil

iex> EVM.Stack.peek([1, 2])
1
Link to this function peek_n(stack, n) 
peek_n(t, integer) :: [EVM.val]

Peeks at n elements of stack, and raises if unsufficient elements exist.

Examples 

iex> EVM.Stack.peek_n([1, 2, 3], 2)
[1, 2]

iex> EVM.Stack.peek_n([1, 2, 3], 4)
[1, 2, 3]
Link to this function pop(stack) 
pop(t) :: {EVM.val, t}

Pops value from stack, returning a new stack with value popped.

This function raises if stack is empty.

Examples 

iex> EVM.Stack.pop([1, 2, 3])
{1, [2, 3]}

iex> EVM.Stack.pop([5])
{5, []}

iex> EVM.Stack.pop([])
** (FunctionClauseError) no function clause matching in EVM.Stack.pop/1
Link to this function pop_n(stack, n) 
pop_n(t, integer) :: {[EVM.val], t}

Pops multiple values off of stack, returning a new stack less that many elements.

Raises if stack contains insufficient elements.

## Examples

iex> EVM.Stack.pop_n([1, 2, 3], 0)
  {[], [1, 2, 3]}

  iex> EVM.Stack.pop_n([1, 2, 3], 1)
  {[1], [2, 3]}

  iex> EVM.Stack.pop_n([1, 2, 3], 2)
  {[1, 2], [3]}

  iex> EVM.Stack.pop_n([1, 2, 3], 4)
  {[1, 2, 3], []}
Link to this function push(stack, val) 
push(t, EVM.val | [EVM.val]) :: t

Pushes value onto stack.

Examples 

iex> EVM.Stack.push([], 5)
[5]

iex> EVM.Stack.push([5], 6)
[6, 5]

iex> EVM.Stack.push([], [5, 6])
[5, 6]