Function write_json_ast_node

prqlc/prqlc/src/debug/render_html.rs:362–411

A hacky way to reconstruct AST nodes from their JSON serialization. Finds structures that look like `{ "BinOp": { ... }, "span": ... }` and converts them to ` ... `.

(
    w: &mut W,
    node: serde_json::Value,
    is_node_contents: bool,
)

/// Finds structures that look like `{ "BinOp": { ... }, "span": ... }`
/// and converts them to `<div class=ast-node>...</div>`.
fn write_json_ast_node<W: Write>(
    w: &mut W,
    node: serde_json::Value,
    is_node_contents: bool,
) -> Result {
    match node {
        serde_json::Value::Null => write!(w, "None"),
        serde_json::Value::Bool(b) => write!(w, "{b}"),
        serde_json::Value::Number(n) => write!(w, "{n}"),
        serde_json::Value::String(s) => write!(w, "{s}"),
        serde_json::Value::Array(items) => {
            writeln!(w, r#"<ul class="json-array">"#)?;
            for item in items {
                write!(w, "<li>")?;
                write_json_ast_node(w, item, false)?;
                write!(w, "</li>")?;
            }
            writeln!(w, "</ul>")?;
            Ok(())
        }
        serde_json::Value::Object(properties) => {
            let is_ast_node = properties.contains_key("span")
                || properties.contains_key("id")
                || (properties.len() == 1
                    && !is_node_contents
                    && properties.values().next().unwrap().is_object());
            if is_ast_node {
                return write_ast_node_from_object(w, properties);
            }

            writeln!(w, r#"<div class="json-object">"#)?;
            for (key, value) in properties {
                if key == "ty" || key == "return_ty" {
                    // special case for better type printing
                    let ty_json = value.to_string();
                    if let Ok(ty) = serde_json::from_str::<pr::Ty>(&ty_json) {
                        let ty_prql = escape_html(&codegen::write_ty(&ty));
                        write!(w, r#"<span>{key}: {ty_prql}</span>"#)?;
                    }
                    continue;
                }

                write!(w, r#"<span>{key}: </span><div class="json-value">"#)?;
                write_json_ast_node(w, value, false)?;
                writeln!(w, "</div>")?;
            }
            writeln!(w, "</div>")
        }
    }
}

fn write_ast_node_from_object<W: Write>(
    w: &mut W,