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Stack (Last-In-First-Out)

Pure Nim implementation of a fixed-capacity stack with zero heap allocation.

Features:

Fixed capacity at compile time (no dynamic allocation)
Standard LIFO operations (push/pop/peek)
Audio-rate safe (predictable performance)
Generic type support via templates

Use Cases:

Undo/redo systems
Expression evaluation
Function call tracking
Temporary value storage

Memory:

Stack allocated only
Size known at compile time
Zero runtime overhead

Usage:

import nimphea_stack

# Create stack for 32 floats
var stack: Stack[32, float32]
stack.init()

# Push values
discard stack.push(1.5)
discard stack.push(2.7)

# Pop values (LIFO order)
var value: float32
if stack.pop(value):
  echo value  # 2.7 (last in, first out)

# Peek without removing
if stack.peek(value):
  echo value  # 1.5 (next value, still on stack)

Types

Stack[N; T] = object

Fixed-capacity stack

Generic Parameters:

N - Capacity (must be known at compile time)
T - Element type

Fields:

data - Fixed array storage
top - Current stack top index (-1 when empty)

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Procs

proc `$`[N: static int; T](this: Stack[N, T]): string: Convert stack to string representation (for debugging)

Example:

echo stack # "Stack[32, float32](count=10/32)"
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proc capacity[N: static int; T](this: Stack[N, T]): int {.inline.}: Get maximum capacity

Returns: Maximum capacity (compile-time constant N)

Example:

echo stack.capacity() # 32
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proc clear[N: static int; T](this: var Stack[N, T]): Clear all elements from the stack

Example:

stack.clear()
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proc init[N: static int; T](this: var Stack[N, T]): Initialize the stack

Example:

var stack: Stack[16, int] stack.init()
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proc isEmpty[N: static int; T](this: Stack[N, T]): bool {.inline.}: Check if stack is empty

Returns: true if empty, false otherwise

Example:

if stack.isEmpty(): echo "Stack is empty"
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proc isFull[N: static int; T](this: Stack[N, T]): bool {.inline.}: Check if stack is full

Returns: true if full, false otherwise

Example:

if stack.isFull(): echo "Stack is full, cannot push"
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proc len[N: static int; T](this: Stack[N, T]): int {.inline.}: Get current number of elements

Returns: Number of elements (0 to N)

Example:

echo stack.len() # e.g., 10
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proc peek[N: static int; T](this: Stack[N, T]; value: var T): bool {.inline.}: Peek at the top value without removing it

Parameters:

value - Output parameter to receive the peeked value

Returns: true if successful, false if stack was empty

Example:

var val: int if stack.peek(val): echo "Top value: ", val # Stack unchanged
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proc pop[N: static int; T](this: var Stack[N, T]; value: var T): bool {.inline.}: Pop a value from the stack

Parameters:

value - Output parameter to receive the popped value

Returns: true if successful, false if stack was empty

Example:

var val: int if stack.pop(val): echo "Popped: ", val else: echo "Stack empty"
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proc push[N: static int; T](this: var Stack[N, T]; value: T): bool {.inline.}: Push a value onto the stack

Parameters:

value - Element to push

Returns: true if successful, false if stack was full

Example:

if not stack.push(42): echo "Stack full, push failed"
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nimphea/nimphea_stack

Stack (Last-In-First-Out)

Types

Procs