KylerOlsen/YREA-SLS
KylerOlsen
/
YREA-SLS
1
0
Fork 0
Code Releases 3 Wiki Activity
YREA-SLS/stack_lang_spec_v03.md

817 lines
17 KiB
Markdown
Raw Blame History

# Stack Language Specification v0.3
## 1. Overview
A statically-typed, stack-based language with pure postfix notation combining the execution model of HP's RPL, the type system of C and Rust, and modern array operations from Uiua.
### Design Principles
- **Everything is postfix** - no exceptions
- Stack-based execution (no local variables)
- Static typing with type inference
- Manual heap memory management
- Types define what things **are**, traits define how things **act**
- All constructs are implicitly generic
- **Every operator is defined by a trait**
## 2. Lexical Structure
### 2.1 Comments
```
// Single-line comment
```
### 2.2 Identifiers
- Start with letter or underscore: `[a-zA-Z_][a-zA-Z0-9_]*`
- Case-sensitive
- Trait names prefixed with `::` (e.g., `::Addable`, `::Number`)
### 2.3 Literals
**Integer Literals**
```
42 // i32 (default)
42 i64 // Annotate as i64
0xFF // hexadecimal
0b1010 // binary
```
**Floating Point Literals**
```
3.14 // f64 (default)
3.14 f32 // Annotate as f32
```
**String Literals**
```
"hello world"
"escape sequences: \n \t \\ \""
```
**Boolean Literals**
```
true
false
```
**Array Literals**
```
[1 2 3 4 5] // array of i32
[1.0 2.0 3.0] // array of f64
[[1 2] [3 4]] // 2D array
```
## 3. Type System
### 3.1 Primitive Types
- `i8`, `i16`, `i32`, `i64` - Signed integers
- `u8`, `u16`, `u32`, `u64` - Unsigned integers
- `f32`, `f64` - Floating point
- `bool` - Boolean
- `char` - Single character (UTF-8)
- `ptr` - Raw pointer (generic over pointed type)
### 3.2 Types vs Traits
**Types** define the concrete structure and memory layout:
```
Point struct // Point is a type
Rectangle struct // Rectangle is a type
```
**Traits** define behavioral contracts - how things act:
```
::Drawable trait // Drawable is a trait
::Addable trait // Addable is a trait
```
**Key Distinction:**
- A value **has** a type (what it is structurally)
- A value **implements** a trait (how it behaves)
- Types are concrete; traits are interfaces
- Functions can be generic over both types and traits
- **Every operator must be backed by a trait**
### 3.3 All Constructs are Generic
Every function, struct, and union is implicitly generic. Constraints are specified via traits:
```
// Function generic over any type T
(T -- T) { dup * } square fn
// Function requiring T to implement Addable trait
(T T -- T) ::Addable { + } add_two fn
// Struct generic over field types
(T T --) { x: y: } Point struct
// Union generic over variant types
(T --) { Some(T) None } Option union
```
## 4. Base Traits (Non-Exhaustive)
### 4.1 Core Traits
**::Pushable** - Can be pushed onto the stack
```
{ (-- Self) push: } ::Pushable trait
```
**::ArrayOf** - Array container trait
```
{ (-- ArrayOf[T]) create: (ArrayOf[T] i32 -- T) at: } ::ArrayOf trait
```
**::Addable** - Supports addition and subtraction
```
{ (Self Self -- Self) +: (Self Self -- Self) -: } ::Addable trait
```
**::Number** - Numeric operations
```
// Number inherits from multiple traits
[ ::Addable ::Multiplyable ::Comparable ] ::Number inher
```
**::String** - String operations
```
{ (Self Self -- Self) concat: (Self -- i32) length: } ::String trait
```
**::Identifier** - Represents identifiers/symbols
```
{ (-- TokenString) name: } ::Identifier trait
```
**::Trait** - Meta-trait for trait operations
```
{ (TokenString Identifier --) trait: (Identifier TokenString Identifier --) impl: (ArrayOf[Identifier] Identifier --) inher: } ::Trait trait
```
### 4.2 Additional Core Traits
**::Multiplyable** - Multiplication and division
```
{ (Self Self -- Self) *: (Self Self -- Self) /: (Self Self -- Self) %: } ::Multiplyable trait
```
**::Comparable** - Comparison operations
```
{ (Self Self -- bool) >: (Self Self -- bool) >=: (Self Self -- bool) <: (Self Self -- bool) <=: (Self Self -- bool) ==: (Self Self -- bool) !=: } ::Comparable trait
```
**::Logical** - Logical operations
```
{ (Self Self -- Self) and: (Self Self -- Self) or: (Self -- Self) not: } ::Logical trait
```
**::Bitwise** - Bitwise operations
```
{ (Self Self -- Self) bitand: (Self Self -- Self) bitor: (Self Self -- Self) bitxor: (Self -- Self) bitnot: (Self i32 -- Self) shl: (Self i32 -- Self) shr: } ::Bitwise trait
```
**::Exponentiable** - Exponentiation
```
{ (Self Self -- Self) ^: } ::Exponentiable trait
```
## 5. Stack Operations
### 5.1 Stack Manipulation
All stack operations are backed by traits.
```
dup // ( a -- a a ) Duplicate top [::Duplicable]
drop // ( a -- ) Remove top [::Droppable]
swap // ( a b -- b a ) Swap top two [::Swappable]
over // ( a b -- a b a ) Copy second to top [::Overable]
rot // ( a b c -- b c a ) Rotate three items [::Rotatable]
```
### 5.2 Stack Inspection
```
depth // ( -- n ) Push stack depth [::Inspectable]
pick // ( n -- x ) Copy nth item to top (0 = top) [::Pickable]
roll // ( n times -- ) Rotate n items, times times [::Rollable]
```
**Roll Examples:**
```
// Stack: a b c d e
3 1 roll // Rotate top 3 items once: a b d e c
3 2 roll // Rotate top 3 items twice: a b e c d
5 1 roll // Rotate all 5 items once: b c d e a
```
## 6. Operators (Postfix)
**Every operator is backed by a trait and must be implemented for types that use it.**
### 6.1 Arithmetic (::Addable, ::Multiplyable, ::Exponentiable)
```
3 4 + // ( a b -- result ) Addition [::Addable]
10 3 - // Subtraction [::Addable]
5 6 * // Multiplication [::Multiplyable]
20 4 / // Division [::Multiplyable]
17 5 % // Modulo [::Multiplyable]
2 8 ^ // Exponentiation [::Exponentiable]
```
### 6.2 Comparison (::Comparable)
```
5 3 > // Greater than [::Comparable]
5 3 >= // Greater or equal [::Comparable]
5 3 < // Less than [::Comparable]
5 3 <= // Less or equal [::Comparable]
5 5 == // Equal [::Comparable]
5 3 != // Not equal [::Comparable]
```
### 6.3 Logical (::Logical)
```
true false and // Logical AND [::Logical]
true false or // Logical OR [::Logical]
true not // Logical NOT [::Logical]
```
### 6.4 Bitwise (::Bitwise)
```
0xFF 0x0F bitand // Bitwise AND [::Bitwise]
0xFF 0x0F bitor // Bitwise OR [::Bitwise]
0xFF 0x0F bitxor // Bitwise XOR [::Bitwise]
0xFF bitnot // Bitwise NOT [::Bitwise]
8 2 shl // Left shift [::Bitwise]
8 2 shr // Right shift [::Bitwise]
```
## 7. Trait System
### 7.1 Trait Definition
**Syntax**: `{ function_signatures } ::name trait`
```
// Simple trait
{
(Self -- ) draw:
} ::Drawable trait
// Trait with multiple methods
{
(Self Self -- Self) add:
(Self Self -- Self) sub:
(Self -- Self) neg:
} ::Numeric trait
// The comprehensive Trait meta-trait
{
(TokenString Identifier --) trait:
(Identifier TokenString Identifier --) impl:
(ArrayOf[Identifier] Identifier --) inher:
} ::Implementable trait
```
### 7.2 Trait Implementation
**Syntax**: `::type { method_implementations } ::trait impl`
```
// Implement Addable for i32
::i32 {
(Self Self -- Self) {
// Native addition implementation
} +:
(Self Self -- Self) {
// Native subtraction implementation
} -:
} ::Addable impl
// Implement Drawable for Rectangle
::Rectangle {
(Rectangle -- ) {
"Drawing rectangle" print
dup width get print
height get print
} draw:
} ::Drawable impl
```
### 7.3 Trait Inheritance
**Syntax**: `[ ::trait1 ::trait2 ... ] ::derived_trait inher`
```
// Number inherits from Addable and Multiplyable
[ ::Addable ::Multiplyable ] ::Number inher
// Numeric inherits from Number, Comparable, and Exponentiable
[ ::Number ::Comparable ::Exponentiable ] ::Numeric inher
// Complex inheritance
[ ::Drawable ::Transformable ::Collidable ] ::GameObject inher
```
### 7.4 Using Traits in Functions
```
// Function requiring Drawable trait
(T -- ) ::Drawable {
draw
} draw_twice fn
// Multiple trait requirements
(T -- T) ::Numeric ::Copyable {
dup abs swap dup * +
} complex_calc fn
```
## 8. Functions (Postfix Definition)
Functions are defined in postfix notation. The signature and body come before the name.
### 8.1 Basic Function Definition
**Syntax**: `(inputs -- outputs) { body } name fn`
```
// Define a square function
(i32 -- i32) { dup * } square fn
// Use it
5 square // 25
// Multiple inputs and outputs
(i32 i32 -- i32 i32) {
2dup / swap %
} divmod fn
10 3 divmod // 3 1 (quotient remainder)
```
### 8.2 Generic Functions with Trait Constraints
**Syntax**: `(type_sig) ::trait_constraints { body } name fn`
```
// Generic identity - works with any type
(T -- T) {} identity fn
// Requires T to be Addable
(T T -- T) ::Addable {
+
} add_values fn
// Multiple trait constraints
(T U -- U T) ::Copyable ::Swappable {
swap
} swap_generic fn
// Multiple type parameters with different traits
(T U -- T) ::Addable ::Numeric {
dup U as +
} add_converted fn
```
## 9. Control Flow (Postfix)
### 9.1 Conditionals
**Syntax**: `condition { then-block } { else-block } if`
```
// if-then (else block is empty)
x 0 > { "positive" print } {} if
// if-then-else
x 0 >
{ "positive" print }
{ "non-positive" print }
if
// The condition comes first, then both blocks, then 'if'
a b >
{ a }
{ b }
if max set
// Nested
x 0 >
{
y 0 >
{ "both positive" print }
{ "x positive, y not" print }
if
}
{ "x not positive" print }
if
```
### 9.2 Loops
**While Loop**
**Syntax**: `{ condition-block } { body-block } while`
```
// Sum 1 to 10
0 1 // sum counter
{ dup 10 <= } // condition block
{ // body block
over over + // Add counter to sum
swap 1 + swap // Increment counter
}
while
drop // Drop counter, leave sum
// Infinite loop with break
{ true } {
// body
condition { break } {} if
} while
```
**For Loop**
**Syntax**: `start end { body-with-counter } for`
```
// The loop variable is implicitly pushed to stack in each iteration
1 10 {
// Stack has loop counter on top
dup print
} for
// More complex
1 100 {
dup fizzbuzz
} for
```
### 9.3 Loop Control
```
break // Exit loop
continue // Skip to next iteration
```
### 9.4 Match/Pattern Matching
**Syntax**: `value { pattern => block ... } match`
```
value {
Some(x) => { x print }
None => { "Nothing" print }
} match
// With multiple patterns
status {
Pending => { "Waiting" print }
Active => { "Running" print }
Complete => { "Done" print }
} match
```
## 10. Data Structures (Postfix)
### 10.1 Struct Definition
**Syntax**: `(field_types -- ) { field_names } name struct`
```
// Define Point struct - generic over coordinate types
(T T --) { x: y: } Point struct
// Use with specific types
3.0 4.0 Point // Creates Point with f64 fields
3 4 Point // Creates Point with i32 fields
// More complex struct
(T U V --) {
width:
height:
depth:
} Box3D struct
10.0 20.0 30.0 Box3D
```
### 10.2 Struct Field Access
**Syntax (postfix)**: `struct field get` or `struct value field set`
```
point x get // Get x field
point 15.0 x set // Set x field to 15.0
// Chaining
point x get 2 * y get + // (point.x * 2) + point.y
```
### 10.3 Union Definition
**Syntax**: `(variant_types -- ) { variants } name union`
```
// Option type - generic over T
(T --) {
Some(T)
None
} Option union
// Result type - generic over T and E
(T E --) {
Ok(T)
Err(E)
} Result union
// Create union values
42 Some // Creates Option::Some(42)
None // Creates Option::None
"success" Ok // Creates Result::Ok("success")
"error" Err // Creates Result::Err("error")
```
### 10.4 Enum Definition
**Syntax**: `() { variants } name enum`
```
() {
Pending
Active
Complete
} Status enum
// Usage
Pending // Creates Status::Pending
Active // Creates Status::Active
```
## 11. Memory Management (Postfix)
### 11.1 Heap Operations
```
// Allocate
3.0 4.0 Point alloc // ( Point -- ptr<Point> )
// Dereference
ptr deref // ( ptr<T> -- T )
// Store (dereference and update)
new_value ptr store // ( T ptr<T> -- )
// Free
ptr free // ( ptr<T> -- )
```
### 11.2 Example
```
// Create heap-allocated point
3.0 4.0 Point alloc // Returns ptr<Point>
dup x get print // Dereference and print x
free // Clean up
```
## 12. Array Operations (Postfix)
### 12.1 Basic Array Operations
```
// Creation
1 10 range // Create range array [1..10]
// Shape operations
arr shape // Get shape
arr 2 3 reshape // Reshape to 2x3
// Element access
arr 2 at // Index access
arr 1 3 slice // Slice array
```
### 12.2 Array Combinators
```
// Map - apply function to each element
[1 2 3 4] { 2 * } map // [2 4 6 8]
// Filter - keep elements matching predicate
[1 2 3 4 5] { 2 % 0 == } filter // [2 4]
// Reduce - fold with function
[1 2 3 4] 0 { + } reduce // 10
// Each - apply to each element (side effects)
[[1 2] [3 4]] { sum print } each
```
### 12.3 Array Arithmetic
```
[1 2 3] [4 5 6] +. // Element-wise add: [5 7 9]
[1 2 3] [4 5 6] *. // Element-wise multiply: [4 10 18]
[1 2 3] 2 *. // Scalar multiply: [2 4 6]
```
### 12.4 Array Manipulation
```
[1 2 3] [4 5 6] concat // Concatenate: [1 2 3 4 5 6]
[1 2 3] reverse // [3 2 1]
[[1 2] [3 4]] transpose // [[1 3] [2 4]]
[1 2 3 4] 2 window // [[1 2] [2 3] [3 4]]
```
## 13. Eval Operator (Postfix)
Execute code dynamically at runtime.
```
// Evaluate string as code
"2 3 +" eval // Pushes 5
// Build and execute code
"(i32 -- i32) { dup * } square fn" eval
5 square // 25
// Dynamic dispatch
operation_name " get" concat eval
```
## 14. Standard Library Concepts
### 14.1 I/O
```
"Hello" print // Print to stdout
"Enter name: " input // Read from stdin
"file.txt" read // Read file contents
"data" "file.txt" write // Write to file
```
### 14.2 String Operations
```
"hello" " world" concat // Concatenate: "hello world"
"hello" length // 5
"hello" 1 3 substr // "el"
"a,b,c" "," split // ["a" "b" "c"]
["a" "b"] "," join // "a,b"
```
### 14.3 Type Conversion
```
42 f64 as // Convert i32 to f64
"123" i32 parse // Parse string to i32
3.14 str as // Convert to string
```
## 15. Complete Examples
### 15.1 Trait Implementation Example
```
// Define the Addable trait
{
(Self Self -- Self) +:
(Self Self -- Self) -:
} ::Addable trait
// Implement for i32
::i32 {
(Self Self -- Self) {
// Native addition
} +:
(Self Self -- Self) {
// Native subtraction
} -:
} ::Addable impl
// Implement for Point
::Point {
(Point Point -- Point) {
over x get over x get +
swap y get swap y get +
Point
} +:
(Point Point -- Point) {
over x get over x get -
swap y get swap y get -
Point
} -:
} ::Addable impl
```
### 15.2 Trait Inheritance Example
```
// Define base traits
{ (Self Self -- Self) +: (Self Self -- Self) -: } ::Addable trait
{ (Self Self -- Self) *: (Self Self -- Self) /: } ::Multiplyable trait
{ (Self Self -- Self) ^: } ::Exponentiable trait
// Number inherits from multiple traits
[ ::Addable ::Multiplyable ] ::Number inher
// Numeric extends Number further
[ ::Number ::Exponentiable ] ::Numeric inher
```
### 15.3 Factorial
```
(i32 -- i32) {
dup 1
{ drop 1 }
{ dup 1 - factorial * }
<= if
} factorial fn
5 factorial print // 120
```
### 15.4 FizzBuzz
```
(i32 -- ) {
dup 15 % 0 ==
{ drop "FizzBuzz" print }
{
dup 3 % 0 ==
{ drop "Fizz" print }
{
dup 5 % 0 ==
{ drop "Buzz" print }
{ print }
if
}
if
}
if
} fizzbuzz fn
1 100 { fizzbuzz } for
```
### 15.5 Using Roll
```
// Stack: 1 2 3 4 5
3 1 roll // Rotate top 3 once: 1 2 4 5 3
3 2 roll // Rotate top 3 twice: 1 2 5 3 4
// More complex example
10 20 30 40 50
4 2 roll // Rotate top 4, twice: 10 30 40 50 20
```
### 15.6 Array Processing
```
// Sum of squares of even numbers from 1 to 10
[1 2 3 4 5 6 7 8 9 10]
{ 2 % 0 == } filter // Keep even numbers
{ dup * } map // Square each
0 { + } reduce // Sum
print // 220
```
## 16. Syntax Summary
### Complete Grammar Patterns
**Functions**: `(in -- out) ::constraints { body } name fn`
**Structs**: `(types -- ) { fields: } name struct`
**Unions**: `(types -- ) { Variant(T) ... } name union`
**Enums**: `() { Variant ... } name enum`
**Traits**: `{ (sig) method: ... } ::name trait`
**Trait Impl**: `::Type { (sig) { body } method: ... } ::Trait impl`
**Trait Inheritance**: `[ ::Trait1 ::Trait2 ] ::NewTrait inher`
**If**: `condition { then } { else } if`
**While**: `{ condition } { body } while`
**For**: `start end { body } for`
**Match**: `value { pattern => block ... } match`
---
**Version**: 0.3
**Status**: Draft Specification - Trait-Backed Operations Edition
View Git Blame Copy Permalink