squawk-syntax 2.29.0

// via https://github.com/rust-lang/rust-analyzer/blob/d8887c0758bbd2d5f752d5bd405d4491e90e7ed6/crates/syntax/src/ast/node_ext.rs
//
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use std::borrow::Cow;

use rowan::{GreenNodeData, GreenTokenData, NodeOrToken};

use crate::ast;
use crate::ast::AstNode;
use crate::{SyntaxNode, TokenText};

use super::support;

impl ast::Constraint {
    #[inline]
    pub fn name(&self) -> Option<ast::Name> {
        support::child(self.syntax())
    }
}

impl ast::BinExpr {
    pub fn lhs(&self) -> Option<ast::Expr> {
        support::children(self.syntax()).next()
    }

    pub fn rhs(&self) -> Option<ast::Expr> {
        support::children(self.syntax()).nth(1)
    }
}

impl ast::NameRef {
    #[inline]
    pub fn text(&self) -> TokenText<'_> {
        text_of_first_token(self.syntax())
    }
}

impl ast::Name {
    #[inline]
    pub fn text(&self) -> TokenText<'_> {
        text_of_first_token(self.syntax())
    }
}

impl ast::CharType {
    #[inline]
    pub fn text(&self) -> TokenText<'_> {
        text_of_first_token(self.syntax())
    }
}

pub(crate) fn text_of_first_token(node: &SyntaxNode) -> TokenText<'_> {
    fn first_token(green_ref: &GreenNodeData) -> &GreenTokenData {
        green_ref
            .children()
            .next()
            .and_then(NodeOrToken::into_token)
            .unwrap()
    }

    match node.green() {
        Cow::Borrowed(green_ref) => TokenText::borrowed(first_token(green_ref).text()),
        Cow::Owned(green) => TokenText::owned(first_token(&green).to_owned()),
    }
}