From 177c42cae75d8a0d9985c26ea28cb4f1cf7077de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kat=20March=C3=A1n?= <kzm@zkat.tech>
Date: Sat, 23 Apr 2022 02:15:31 -0700
Subject: [PATCH] feat(len): add APIs to calculate component lengths (#36)

Fixes: https://github.com/kdl-org/kdl-rs/issues/19
---
 src/document.rs   | 10 ++++++++++
 src/entry.rs      | 10 ++++++++++
 src/identifier.rs | 10 ++++++++++
 src/node.rs       | 10 ++++++++++
 4 files changed, 40 insertions(+)

diff --git a/src/document.rs b/src/document.rs
index cbb780a..3c89553 100644
--- a/src/document.rs
+++ b/src/document.rs
@@ -168,6 +168,16 @@ impl KdlDocument {
         self.trailing = Some(trailing.into());
     }
 
+    /// Length of this document when rendered as a string.
+    pub fn len(&self) -> usize {
+        format!("{}", self).len()
+    }
+
+    /// Returns true if this document is completely empty (including whitespace)
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Clears leading and trailing text (whitespace, comments). `KdlNode`s in
     /// this document will be unaffected.
     pub fn clear_fmt(&mut self) {
diff --git a/src/entry.rs b/src/entry.rs
index 0cf5c04..5533266 100644
--- a/src/entry.rs
+++ b/src/entry.rs
@@ -98,6 +98,16 @@ impl KdlEntry {
         self.value_repr = Some(repr.into());
     }
 
+    /// Length of this entry when rendered as a string.
+    pub fn len(&self) -> usize {
+        format!("{}", self).len()
+    }
+
+    /// Returns true if this entry is completely empty (including whitespace).
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Auto-formats this entry.
     pub fn fmt(&mut self) {
         self.leading = None;
diff --git a/src/identifier.rs b/src/identifier.rs
index ef260f1..d633eaf 100644
--- a/src/identifier.rs
+++ b/src/identifier.rs
@@ -31,6 +31,16 @@ impl KdlIdentifier {
         self.repr = Some(repr.into());
     }
 
+    /// Length of this identifier when rendered as a string.
+    pub fn len(&self) -> usize {
+        format!("{}", self).len()
+    }
+
+    /// Returns true if this identifier is completely empty.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Resets this identifier to its default representation. It will attempt
     /// to make it an unquoted identifier, and fall back to a string
     /// representation if that would be invalid.
diff --git a/src/node.rs b/src/node.rs
index 93e2fce..b31d990 100644
--- a/src/node.rs
+++ b/src/node.rs
@@ -106,6 +106,16 @@ impl KdlNode {
         self.trailing = Some(trailing.into());
     }
 
+    /// Length of this node when rendered as a string.
+    pub fn len(&self) -> usize {
+        format!("{}", self).len()
+    }
+
+    /// Returns true if this node is completely empty (including whitespace).
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Clears leading and trailing text (whitespace, comments), as well as
     /// the space before the children block, if any. Individual entries and
     /// their formatting will be preserved.