improve PPtr functions

1 files changed, 28 insertions, 6 deletions

diff --git a/src/classes/pptr.rs b/src/classes/pptr.rs
index d6e4bb6..30f37ad 100644
--- a/src/classes/pptr.rs
+++ b/src/classes/pptr.rs
@@ -1,11 +1,17 @@
-use super::HValue;
-use crate::object::{Value, parser::FromValue};
+use crate::{
+    object::{Value, parser::FromValue},
+    serialized_file::SerializedFile,
+};
 use anyhow::{Result, anyhow, bail};
+use log::debug;
 use serde::Serialize;
-use std::marker::PhantomData;
+use std::{
+    io::{Read, Seek},
+    marker::PhantomData,
+};
 
 #[derive(Debug, Serialize)]
-pub struct PPtr<T = HValue> {
+pub struct PPtr<T = Value> {
     #[serde(skip, default)]
     _class: PhantomData<T>,
     pub class: String,
@@ -36,8 +42,8 @@ impl<T> FromValue for PPtr<T> {
     }
 }
 
-impl PPtr {
-    pub fn cast<T>(self) -> PPtr<T> {
+impl<T: FromValue> PPtr<T> {
+    pub fn cast<U>(self) -> PPtr<U> {
         PPtr {
             _class: PhantomData,
             class: self.class,
@@ -45,4 +51,20 @@ impl PPtr {
             path_id: self.path_id,
         }
     }
+    pub fn is_null(&self) -> bool {
+        self.path_id == 0 && self.file_id == 0
+    }
+    pub fn load(&self, file: &mut SerializedFile<impl Read + Seek>) -> Result<T> {
+        debug!(
+            "loading PPtr<{}> file_id={} path_id={}",
+            self.class, self.file_id, self.path_id
+        );
+        let ob = file
+            .objects
+            .iter()
+            .find(|o| o.path_id == self.path_id)
+            .ok_or(anyhow!("object with path id {} not found", self.path_id))?
+            .to_owned();
+        file.read_object(ob)?.parse()
+    }
 }