3. The language

• 3.1. Program Structure
  • 3.1.1. File Layout
  • 3.1.2. Module Declaration
    • 3.1.2.1. Modifiers
  • 3.1.3. Require Declaration
    • 3.1.3.1. Re-exporting
    • 3.1.3.2. Aliasing
  • 3.1.4. Options Declaration
  • 3.1.5. Top-Level Declarations
  • 3.1.6. Visibility
  • 3.1.7. Entry Points
    • 3.1.7.1. [export]
    • 3.1.7.2. [init]
    • 3.1.7.3. [finalize]
  • 3.1.8. Expect Declaration
  • 3.1.9. Program vs. Module
  • 3.1.10. Execution Lifecycle
  • 3.1.11. Complete Example
• 3.2. Lexical Structure
  • 3.2.1. Identifiers
  • 3.2.2. Keywords
  • 3.2.3. Operators
  • 3.2.4. Other Tokens
  • 3.2.5. Literals
    • 3.2.5.1. Numeric Literals
    • 3.2.5.2. String Literals
  • 3.2.6. Comments
  • 3.2.7. Automatic Semicolons
• 3.3. Values and Data Types
  • 3.3.1. Integer
  • 3.3.2. Float
  • 3.3.3. Bool
  • 3.3.4. String
  • 3.3.5. Type Conversion and Casting
    • 3.3.5.1. Explicit numeric casts
    • 3.3.5.2. Enumeration casts
    • 3.3.5.3. String conversion
    • 3.3.5.4. What is NOT allowed
  • 3.3.6. Table
  • 3.3.7. Array
  • 3.3.8. Struct
  • 3.3.9. Classes
  • 3.3.10. Variant
  • 3.3.11. Tuple
  • 3.3.12. Enumeration
  • 3.3.13. Bitfield
  • 3.3.14. Function
  • 3.3.15. Reference
  • 3.3.16. Pointers
  • 3.3.17. Smart Pointers
    • 3.3.17.1. Ownership transfer functions
  • 3.3.18. Iterators
• 3.4. Pointers
  • 3.4.1. Pointer types
  • 3.4.2. Creating pointers
    • 3.4.2.1. new
    • 3.4.2.2. addr
    • 3.4.2.3. safe_addr
  • 3.4.3. Dereferencing
  • 3.4.4. Null safety
    • 3.4.4.1. Null checks
    • 3.4.4.2. Safe navigation ?.
    • 3.4.4.3. Null coalescing ??
  • 3.4.5. Deletion
  • 3.4.6. Pointer arithmetic
    • 3.4.6.1. Indexing
    • 3.4.6.2. Increment and addition
  • 3.4.7. Const widening when passing args
  • 3.4.8. Void pointers
  • 3.4.9. intptr
  • 3.4.10. reinterpret
  • 3.4.11. Type info
  • 3.4.12. Summary
• 3.5. Constants, Enumerations, Global variables
  • 3.5.1. Constant
  • 3.5.2. Global variable
  • 3.5.3. Enumeration
• 3.6. Statements
  • 3.6.1. Visibility Block
  • 3.6.2. Control Flow Statements
    • 3.6.2.1. if/elif/else
    • 3.6.2.2. static_if / static_elif
    • 3.6.2.3. while
  • 3.6.3. Ranged Loops
    • 3.6.3.1. for
  • 3.6.4. break
  • 3.6.5. continue
  • 3.6.6. return
  • 3.6.7. yield
  • 3.6.8. pass
  • 3.6.9. finally
  • 3.6.10. Local Variable Declarations
  • 3.6.11. assume
  • 3.6.12. with
  • 3.6.13. delete
  • 3.6.14. Function Declaration
  • 3.6.15. try/recover
  • 3.6.16. panic
  • 3.6.17. label and goto
  • 3.6.18. Expression Statement
  • 3.6.19. Global Variables
  • 3.6.20. enum
  • 3.6.21. typedef
• 3.7. Expressions
  • 3.7.1. Assignment
  • 3.7.2. Operators
    • 3.7.2.1. Arithmetic
    • 3.7.2.2. Relational
    • 3.7.2.3. Logical
    • 3.7.2.4. Bitwise Operators
    • 3.7.2.5. Pipe Operators
    • 3.7.2.6. Interval Operator
    • 3.7.2.7. Null-Coalescing Operator (??)
    • 3.7.2.8. Ternary Operator (? :)
    • 3.7.2.9. Null-Safe Navigation (?. and ?[)
    • 3.7.2.10. Type Operators (is, as, ?as)
    • 3.7.2.11. is type<T>
    • 3.7.2.12. Cast, Upcast, and Reinterpret
    • 3.7.2.13. Dereference
    • 3.7.2.14. Address-of
    • 3.7.2.15. Dot Operator Bypass
    • 3.7.2.16. Safe Index (?[)
    • 3.7.2.17. Unsafe Expression
    • 3.7.2.18. Operators Precedence
  • 3.7.3. Array Initializer
  • 3.7.4. Struct, Class, and Handled Type Initializer
  • 3.7.5. Tuple Initializer
  • 3.7.6. Variant Initializer
  • 3.7.7. Table Initializer
  • 3.7.8. default and new
  • 3.7.9. typeinfo
  • 3.7.10. String Interpolation
• 3.8. Function
  • 3.8.1. Function declaration
    • 3.8.1.1. Single-expression body
    • 3.8.1.2. Publicity
    • 3.8.1.3. Function calls
    • 3.8.1.4. Named Arguments Function call
    • 3.8.1.5. Function pointer
    • 3.8.1.6. Nameless functions
    • 3.8.1.7. Generic functions
    • 3.8.1.8. Function overloading
    • 3.8.1.9. Default Parameters
  • 3.8.2. OOP-style calls
  • 3.8.3. Tail Recursion
  • 3.8.4. Operator Overloading
  • 3.8.5. Overloadable operators
  • 3.8.6. Unary operators
  • 3.8.7. Compound assignment operators
  • 3.8.8. Index operators
  • 3.8.9. Clone and finalize operators
  • 3.8.10. is, as, and ?as operators
  • 3.8.11. Null-coalesce operator
  • 3.8.12. Struct method operators
  • 3.8.13. Overloading the ‘.’ and ‘?.’ operators
  • 3.8.14. Overloading accessors
• 3.9. Block
• 3.10. Lambda
  • 3.10.1. Capture
  • 3.10.2. Iterators
  • 3.10.3. Implementation details
• 3.11. Generator
  • 3.11.1. implementation details
• 3.12. Struct
  • 3.12.1. Struct Declaration
  • 3.12.2. Structure Function Members
  • 3.12.3. Inheritance
  • 3.12.4. Alignment
  • 3.12.5. OOP implementation details
• 3.13. Class
  • 3.13.1. Member Visibility
  • 3.13.2. Initializers
  • 3.13.3. Calling Parent Methods
  • 3.13.4. Runtime Type Checking (is)
  • 3.13.5. Type Casting (as, ?as)
  • 3.13.6. Class Templates
  • 3.13.7. Static methods with [class_method]
    • 3.13.7.1. def static — mutable method
    • 3.13.7.2. def static const — const method
    • 3.13.7.3. [explicit_const_class_method]
    • 3.13.7.4. Complete [class_method] example
  • 3.13.8. Stack-Allocated Classes (using)
  • 3.13.9. Complete Example
  • 3.13.10. Implementation details
• 3.14. Tuple
  • 3.14.1. Passing tuples as arguments — const widening
• 3.15. Variant
  • 3.15.1. Alignment and data layout
• 3.16. Bitfield
• 3.17. Type Aliases
  • 3.17.1. typedef Declaration
  • 3.17.2. Publicity
  • 3.17.3. Shorthand Type Alias Syntax
    • 3.17.3.1. Tuple Aliases
    • 3.17.3.2. Variant Aliases
    • 3.17.3.3. Bitfield Aliases
  • 3.17.4. Local Type Aliases
  • 3.17.5. Generic Type Aliases (auto)
  • 3.17.6. Type Aliases with typedecl
• 3.18. Array
• 3.19. Table
• 3.20. Iterator
  • 3.20.1. Making types iterable
  • 3.20.2. builtin iterators
  • 3.20.3. builtin iteration functions
  • 3.20.4. low level builtin iteration functions
  • 3.20.5. next implementation details
• 3.21. Comprehension
• 3.22. String Builder
  • 3.22.1. Basic Usage
  • 3.22.2. Supported Types
  • 3.22.3. Format Specifiers
  • 3.22.4. Escaping Curly Brackets
  • 3.22.5. Multi-line Strings
  • 3.22.6. Implementation Notes
  • 3.22.7. Relationship to print
• 3.23. Modules
  • 3.23.1. File-path requires
  • 3.23.2. Native modules
  • 3.23.3. Builtin modules
  • 3.23.4. Shared modules
  • 3.23.5. Module function visibility
• 3.24. Move, Copy, and Clone
  • 3.24.1. Copy (=)
    • 3.24.1.1. Relaxed assign
  • 3.24.2. Move (<-)
    • 3.24.2.1. When to use move
    • 3.24.2.2. Return by move
  • 3.24.3. Clone (:=)
    • 3.24.3.1. When to use clone
    • 3.24.3.2. Clone initialization
  • 3.24.4. Type Compatibility
  • 3.24.5. Variable Initialization
  • 3.24.6. Struct Initialization
  • 3.24.7. Lambda Captures
  • 3.24.8. Containers
  • 3.24.9. Classes
  • 3.24.10. Custom Clone
  • 3.24.11. Quick Reference
• 3.25. Clone
  • 3.25.1. Cloning rules and implementation details
  • 3.25.2. clone_to_move implementation
• 3.26. Finalizer
  • 3.26.1. Rules and implementation details
• 3.27. Temporary types
• 3.28. Unsafe
  • 3.28.1. implicit
  • 3.28.2. other cases
• 3.29. Generic Programming
  • 3.29.1. typeinfo
  • 3.29.2. auto and auto(named)
  • 3.29.3. type contracts and type operations
  • 3.29.4. options
  • 3.29.5. typedecl
  • 3.29.6. generic tuples and type<> expressions
    • 3.29.6.1. Module prefixes in generics
• 3.30. Pattern matching
  • 3.30.1. Enumeration Matching
  • 3.30.2. Matching Variants
  • 3.30.3. Declaring Variables in Patterns
  • 3.30.4. Matching Structs
  • 3.30.5. Using Guards
  • 3.30.6. Tuple Matching
  • 3.30.7. Matching Static Arrays
  • 3.30.8. Dynamic Array Matching
  • 3.30.9. Match Expressions
  • 3.30.10. Matching with ||
  • 3.30.11. [match_as_is] Structure Annotation
  • 3.30.12. [match_copy] Structure Annotation
  • 3.30.13. Static Matching
  • 3.30.14. match_type
  • 3.30.15. Multi-Match
• 3.31. Annotations
  • 3.31.1. Function Annotations
    • 3.31.1.1. Lifecycle
    • 3.31.1.2. Visibility
    • 3.31.1.3. Safety
    • 3.31.1.4. Lint Control
    • 3.31.1.5. Generics and Contracts
    • 3.31.1.6. Optimization and AOT
    • 3.31.1.7. Macros
    • 3.31.1.8. Markers and Hints
  • 3.31.2. Structure and Class Annotations
  • 3.31.3. Macro Registration Annotations (daslib)
  • 3.31.4. Contract Annotations (daslib)
  • 3.31.5. Annotation Syntax Details
• 3.32. Options
  • 3.32.1. Language and Syntax
  • 3.32.2. Lint Control
  • 3.32.3. Optimization
  • 3.32.4. Memory
  • 3.32.5. AOT
  • 3.32.6. Safety and Strictness
  • 3.32.7. Multiple Contexts
  • 3.32.8. Debugging and Profiling
  • 3.32.9. RTTI
  • 3.32.10. Logging
  • 3.32.11. Print Control
  • 3.32.12. Miscellaneous
  • 3.32.13. Module-Registered Options
• 3.33. Macros
  • 3.33.1. Compilation passes
  • 3.33.2. Invoking macros
  • 3.33.3. AstFunctionAnnotation
  • 3.33.4. AstBlockAnnotation
  • 3.33.5. AstStructureAnnotation
  • 3.33.6. AstEnumerationAnnotation
  • 3.33.7. AstVariantMacro
  • 3.33.8. AstReaderMacro
  • 3.33.9. AstCallMacro
  • 3.33.10. AstPassMacro
  • 3.33.11. AstTypeMacro
  • 3.33.12. AstTypeInfoMacro
  • 3.33.13. AstForLoopMacro
  • 3.33.14. AstCaptureMacro
  • 3.33.15. AstCommentReader
  • 3.33.16. AstSimulateMacro
  • 3.33.17. AstVisitor
• 3.34. Reification
  • 3.34.1. Simple example
  • 3.34.2. Quote macros
    • 3.34.2.1. qmacro
    • 3.34.2.2. qmacro_block
    • 3.34.2.3. qmacro_expr
    • 3.34.2.4. qmacro_type
    • 3.34.2.5. qmacro_function
    • 3.34.2.6. qmacro_variable
  • 3.34.3. Escape sequences
    • 3.34.3.1. $i(ident)
    • 3.34.3.2. $f(field-name)
    • 3.34.3.3. $v(value)
    • 3.34.3.4. $e(expression)
    • 3.34.3.5. $b(array-of-expr)
    • 3.34.3.6. $a(arguments)
    • 3.34.3.7. $t(type)
    • 3.34.3.8. $c(call-name)
• 3.35. AST Matching
  • 3.35.1. Simple example
  • 3.35.2. Macros
    • 3.35.2.1. qmatch
    • 3.35.2.2. qmatch_block
    • 3.35.2.3. qmatch_function
  • 3.35.3. Tags
    • 3.35.3.1. $e(var) — expression capture
    • 3.35.3.2. $v(var) — value extraction
    • 3.35.3.3. $i(var) — identifier name
    • 3.35.3.4. $t(var) — type capture
    • 3.35.3.5. $c(var) — call name capture
    • 3.35.3.6. $f(var) — field name capture
    • 3.35.3.7. $a(var) — remaining arguments
    • 3.35.3.8. $b(var) — statement range capture
  • 3.35.4. Wildcards
  • 3.35.5. Type matching
    • 3.35.5.1. auto (type wildcard)
  • 3.35.6. Constant constructors and folding
  • 3.35.7. Generic function matching
  • 3.35.8. Result type
• 3.36. Built-in Functions
  • 3.36.1. Invocation
  • 3.36.2. Assertions
  • 3.36.3. Debug
  • 3.36.4. Panic
  • 3.36.5. Memory & Type Utilities
  • 3.36.6. Array Operations
    • 3.36.6.1. Resize & Reserve
    • 3.36.6.2. Push & Emplace
    • 3.36.6.3. Remove & Erase
    • 3.36.6.4. Access & Search
    • 3.36.6.5. Sorting
    • 3.36.6.6. Swap
  • 3.36.7. Table Operations
    • 3.36.7.1. Lookup
    • 3.36.7.2. Insert & Emplace
    • 3.36.7.3. Remove & Clear
    • 3.36.7.4. Iteration
  • 3.36.8. Iterator Operations
  • 3.36.9. Conversion Functions
  • 3.36.10. Clone
  • 3.36.11. Lock Operations
  • 3.36.12. Serialization
  • 3.36.13. Smart Pointer
  • 3.36.14. Memory Mapping
  • 3.36.15. Vector Construction
  • 3.36.16. Move Helpers
  • 3.36.17. Miscellaneous
• 3.37. Lint Tools
  • 3.37.1. Quick start
  • 3.37.2. Standalone utility
  • 3.37.3. Suppressing specific warnings
  • 3.37.4. Important notes
  • 3.37.5. Paranoid rules
    • 3.37.5.1. LINT001 — unreachable code
    • 3.37.5.2. LINT002 — unused variable
    • 3.37.5.3. LINT003 — variable can be let
    • 3.37.5.4. LINT004 — underscore-prefixed variable is used
    • 3.37.5.5. LINT005 — redundant reinterpret cast
    • 3.37.5.6. LINT006 — division by zero (constant zero divisor)
    • 3.37.5.7. LINT007 — identical left and right operands
    • 3.37.5.8. LINT008 — both ternary branches equivalent
    • 3.37.5.9. LINT009 — then branch equivalent to else branch
  • 3.37.6. Performance rules
    • 3.37.6.1. PERF001 — string += in loop
    • 3.37.6.2. PERF002 — character_at in loop with loop variable
    • 3.37.6.3. PERF003 — character_at anywhere
    • 3.37.6.4. PERF004 — string interpolation reassignment in loop
    • 3.37.6.5. PERF005 — length(string) in while condition
    • 3.37.6.6. PERF006 — push/emplace in loop without reserve()
    • 3.37.6.7. PERF007 — unnecessary string(das_string) in comparison
    • 3.37.6.8. PERF008 — unnecessary get_ptr() for is/as
    • 3.37.6.9. PERF009 — redundant move-init variable immediately returned
    • 3.37.6.10. PERF010 — unnecessary get_ptr() for null comparison
    • 3.37.6.11. PERF011 — unnecessary get_ptr() for field access
    • 3.37.6.12. PERF012 — string(das_string) passed to strings function
    • 3.37.6.13. PERF013 — a += 1 / a -= 1 should be a++ / a--
    • 3.37.6.14. PERF014 — closed-interval char-class range check
    • 3.37.6.15. PERF015 — ternary min / max
    • 3.37.6.16. PERF016 — ternary abs
    • 3.37.6.17. PERF017 — length(s) == 0 should be empty(s)
    • 3.37.6.18. PERF018 — for (i in range(length(arr))) should iterate directly
  • 3.37.7. Style rules
    • 3.37.7.1. STYLE001 — unnecessary <| pipe before block argument
    • 3.37.7.2. STYLE002 — <| pipe before parameterless block
    • 3.37.7.3. STYLE003 — redundant $() on parameterless block
    • 3.37.7.4. STYLE005 — braces around a single-statement early exit
    • 3.37.7.5. STYLE006 — string(__rtti) comparison should use is
    • 3.37.7.6. STYLE010 — if (true) should be a bare block
    • 3.37.7.7. STYLE011 — variable declaration followed by immediate assignment
    • 3.37.7.8. STYLE012 — array<T> initialized by a run of push/emplace
    • 3.37.7.9. STYLE014 — comment block exceeds 3 lines at module/public scope
    • 3.37.7.10. STYLE015 — comment block exceeds 1 line inside a def private
    • 3.37.7.11. STYLE016 — adjacent guards leading to identical early-exit
    • 3.37.7.12. STYLE017 — if (cond) return true; else return false should be return cond
    • 3.37.7.13. STYLE018 — redundant boolean comparison
    • 3.37.7.14. STYLE019 — nested min(max(...)) should be clamp(...)
    • 3.37.7.15. STYLE020 — scalar from_JV should be v ?? defV
    • 3.37.7.16. STYLE021 — repeated table<string; JsonValue?> inserts → named-tuple JV
  • 3.37.8. Tests

4. The Runtime

• 4.1. Context
  • 4.1.1. Initialization and shutdown
  • 4.1.2. Macro contexts
  • 4.1.3. Locking
  • 4.1.4. Lookups
  • 4.1.5. Memory allocation and garbage collection
• 4.2. Locks
  • 4.2.1. Context locks
  • 4.2.2. Array and Table locks
• 4.3. Very safe context
  • 4.3.1. The problem: aliased references
  • 4.3.2. What very_safe_context does
  • 4.3.3. Iteration and container moves
• 4.4. Type Mangling
  • 4.4.1. Primitive types
  • 4.4.2. Qualifiers and modifiers
  • 4.4.3. Pointers
  • 4.4.4. Composite prefixes
  • 4.4.5. Container types
  • 4.4.6. Fixed-size arrays (dim)
  • 4.4.7. Callable types
  • 4.4.8. Structures, handled types, and enumerations
  • 4.4.9. Type aliases
  • 4.4.10. Named arguments
  • 4.4.11. Bitfields
  • 4.4.12. Special / internal types
  • 4.4.13. Remove-qualifiers (generics)
  • 4.4.14. Interop function signatures
    • 4.4.14.1. Examples
  • 4.4.15. Querying mangled names at runtime