Signed-off-by: erick-alcachofa <erick@artichoke.dev>
Complete the transition from a declarations-only parser to a functional
imperative parser. This commit introduces the implementation for all
major statement types, loop constructs, and core control flow logic.
- **Match Case Update**: Updated `grammar.ebnf` to use pipe delimiters
`|id|` for unwrapped variables in match cases, replacing the previous
parenthetical syntax.
- **Labels**: Implemented loop labeling using the `ident := loop`
syntax. Labels are validated to ensure they only prefix valid loop
constructs.
- **Labels and Ranges**: Standardized the use of the `:=` operator for
both loop labels (`label := loop`) and range-for declarations (`let i
:= range`).
- **Conditional Branches**:
- Fully implemented `if` and `else` statements.
- Added support for optional variable unwrapping (e.g., `if (expr)
|val|`).
- Supported `else if` chaining by recursively parsing if-statements
within else-branches.
- **Loops**:
- **C-Style For**: Implemented `for (init; cond; post)` with
optional initializers and post-loop expressions.
- **Range For**: Implemented `for (let i := range)` with mutability
controls.
- **While & Do-While**: Implemented standard condition-based loops.
- **Infinite Loop**: Added the explicit `loop` keyword for infinite
iteration.
- **Loop Dispatch**: Added a lookahead mechanism in
`parseForLoopStatement` to differentiate between C-style and
Range-style loops based on token positioning.
- **Variables**: Implemented `let`/`def` parsing within local scopes,
including type annotations and initializers.
- **Defer Logic**: Implemented `defer` and `errdefer` for scope-guarded
execution.
- **Jumps**: Implemented `break`, `continue` (with optional label
targets), and `return` (with optional expressions).
- **Match & Switch**: Fully implemented branch parsing, with possible
default cases via the `_` (underscore) keyword.
- **Expression Integration**: Stubbed `parseExpression` in a new
`Expressions.cpp` to serve as the integration point for value parsing.
- **OverloadSet**: Integrated `OverloadSet` utility in `Statements.cpp`
to cleanly handle AST node variant visitation for label injection.
- **Error Handling**: Standardized error reporting across all new paths
using `langException`, providing specific "expected" messages for
delimiters and keywords.