squawk-syntax 2.50.0

// via https://github.com/rust-lang/rust-analyzer/blob/d8887c0758bbd2d5f752d5bd405d4491e90e7ed6/crates/syntax/src/ast.rs
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//
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// of the Software.
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mod generated;
mod node_ext;
mod nodes;
mod support;
mod token_ext;
mod traits;

use std::marker::PhantomData;

use crate::syntax_node::{SyntaxNode, SyntaxNodeChildren, SyntaxToken};
use squawk_parser::SyntaxKind;

pub use self::{
    generated::tokens::*,
    node_ext::{BinOp, LitKind, PostfixOp},
    nodes::*,
    traits::{HasCreateTable, HasParamList, HasWithClause, NameLike},
};

/// The main trait to go from untyped `SyntaxNode`  to a typed ast. The
/// conversion itself has zero runtime cost: ast and syntax nodes have exactly
/// the same representation: a pointer to the tree root and a pointer to the
/// node itself.
pub trait AstNode {
    fn can_cast(kind: SyntaxKind) -> bool
    where
        Self: Sized;

    fn cast(syntax: SyntaxNode) -> Option<Self>
    where
        Self: Sized;

    fn syntax(&self) -> &SyntaxNode;
    fn clone_for_update(&self) -> Self
    where
        Self: Sized,
    {
        Self::cast(self.syntax().clone_for_update()).unwrap()
    }
    fn clone_subtree(&self) -> Self
    where
        Self: Sized,
    {
        Self::cast(self.syntax().clone_subtree()).unwrap()
    }
}

/// Like `AstNode`, but wraps tokens rather than interior nodes.
pub trait AstToken {
    fn can_cast(token: SyntaxKind) -> bool
    where
        Self: Sized;

    fn cast(syntax: SyntaxToken) -> Option<Self>
    where
        Self: Sized;

    fn syntax(&self) -> &SyntaxToken;

    fn text(&self) -> &str {
        self.syntax().text()
    }
}

/// An iterator over `SyntaxNode` children of a particular AST type.
#[derive(Debug, Clone)]
pub struct AstChildren<N> {
    inner: SyntaxNodeChildren,
    ph: PhantomData<N>,
}

impl<N> AstChildren<N> {
    fn new(parent: &SyntaxNode) -> Self {
        AstChildren {
            inner: parent.children(),
            ph: PhantomData,
        }
    }
}

impl<N: AstNode> Iterator for AstChildren<N> {
    type Item = N;
    fn next(&mut self) -> Option<N> {
        self.inner.find_map(N::cast)
    }
}