1 files changed, 83 insertions, 0 deletions

diff --git a/crates/ide/src/display.rs b/crates/ide/src/display.rs
new file mode 100644
index 000000000..41b5bdc49
--- /dev/null
+++ b/crates/ide/src/display.rs
@@ -0,0 +1,83 @@
+//! This module contains utilities for turning SyntaxNodes and HIR types
+//! into types that may be used to render in a UI.
+
+mod navigation_target;
+mod short_label;
+
+use syntax::{
+    ast::{self, AstNode, AttrsOwner, GenericParamsOwner, NameOwner},
+    SyntaxKind::{ATTR, COMMENT},
+};
+
+use ast::VisibilityOwner;
+use stdx::format_to;
+
+pub use navigation_target::NavigationTarget;
+pub(crate) use navigation_target::{ToNav, TryToNav};
+pub(crate) use short_label::ShortLabel;
+
+pub(crate) fn function_declaration(node: &ast::Fn) -> String {
+    let mut buf = String::new();
+    if let Some(vis) = node.visibility() {
+        format_to!(buf, "{} ", vis);
+    }
+    if node.async_token().is_some() {
+        format_to!(buf, "async ");
+    }
+    if node.const_token().is_some() {
+        format_to!(buf, "const ");
+    }
+    if node.unsafe_token().is_some() {
+        format_to!(buf, "unsafe ");
+    }
+    if let Some(abi) = node.abi() {
+        // Keyword `extern` is included in the string.
+        format_to!(buf, "{} ", abi);
+    }
+    if let Some(name) = node.name() {
+        format_to!(buf, "fn {}", name)
+    }
+    if let Some(type_params) = node.generic_param_list() {
+        format_to!(buf, "{}", type_params);
+    }
+    if let Some(param_list) = node.param_list() {
+        format_to!(buf, "{}", param_list);
+    }
+    if let Some(ret_type) = node.ret_type() {
+        if ret_type.ty().is_some() {
+            format_to!(buf, " {}", ret_type);
+        }
+    }
+    if let Some(where_clause) = node.where_clause() {
+        format_to!(buf, "\n{}", where_clause);
+    }
+    buf
+}
+
+pub(crate) fn const_label(node: &ast::Const) -> String {
+    let label: String = node
+        .syntax()
+        .children_with_tokens()
+        .filter(|child| !(child.kind() == COMMENT || child.kind() == ATTR))
+        .map(|node| node.to_string())
+        .collect();
+
+    label.trim().to_owned()
+}
+
+pub(crate) fn type_label(node: &ast::TypeAlias) -> String {
+    let label: String = node
+        .syntax()
+        .children_with_tokens()
+        .filter(|child| !(child.kind() == COMMENT || child.kind() == ATTR))
+        .map(|node| node.to_string())
+        .collect();
+
+    label.trim().to_owned()
+}
+
+pub(crate) fn macro_label(node: &ast::MacroCall) -> String {
+    let name = node.name().map(|name| name.syntax().text().to_string()).unwrap_or_default();
+    let vis = if node.has_atom_attr("macro_export") { "#[macro_export]\n" } else { "" };
+    format!("{}macro_rules! {}", vis, name)
+}