Return Option from table_info()

Author: lionel-

crates/ark/src/data_explorer/r_data_explorer.rs

@@ -24,6 +24,7 @@ use amalthea::comm::data_explorer_comm::TableState;
 use amalthea::comm::event::CommManagerEvent;
 use amalthea::socket::comm::CommInitiator;
 use amalthea::socket::comm::CommSocket;
+use anyhow::anyhow;
 use anyhow::bail;
 use crossbeam::channel::Sender;
 use harp::exec::RFunction;
@@ -195,6 +196,9 @@ impl RDataExplorer {
             let table = self.table.get().clone();
             let object = *table;
 
+            let info =
+                harp::table_info(object).ok_or(anyhow!("Unsupported type for data viewer"))?;
+
             let harp::TableInfo {
                 kind,
                 dims:
@@ -203,7 +207,7 @@ impl RDataExplorer {
                         num_cols: total_num_columns,
                     },
                 col_names: column_names,
-            } = harp::table_info(object)?;
+            } = info;
 
             let lower_bound = cmp::min(start_index, total_num_columns) as isize;
             let upper_bound = cmp::min(total_num_columns, start_index + num_columns) as isize;
@@ -258,7 +262,7 @@ impl RDataExplorer {
                     num_cols: num_columns,
                 },
             col_names: _,
-        } = harp::table_info(object)?;
+        } = harp::table_info(object).ok_or(anyhow!("Unsupported type for data viewer"))?;
 
         let state = TableState {
             table_shape: TableShape {
@@ -280,14 +284,16 @@ impl RDataExplorer {
         let table = self.table.get().clone();
         let object = *table;
 
+        let info = harp::table_info(object).ok_or(anyhow!("Unsupported type for data viewer"))?;
+
         let harp::TableInfo {
             dims:
                 harp::TableDim {
                     num_rows: total_num_rows,
                     num_cols: total_num_cols,
                 },
             ..
-        } = harp::table_info(object)?;
+        } = info;
 
         let lower_bound = cmp::min(row_start_index, total_num_rows) as isize;
         let upper_bound = cmp::min(row_start_index + num_rows, total_num_rows) as isize;

crates/harp/src/table.rs

@@ -2,6 +2,7 @@ use libr::*;
 
 use crate::exec::RFunction;
 use crate::exec::RFunctionExt;
+use crate::object::r_length;
 use crate::utils::r_is_data_frame;
 use crate::utils::r_is_matrix;
 use crate::utils::r_typeof;
@@ -19,17 +20,18 @@ pub struct TableInfo {
     pub col_names: ColumnNames,
 }
 
-pub fn table_info(x: SEXP) -> anyhow::Result<TableInfo> {
+// TODO: Might want to encode as types with methods so that we can make
+// assumptions about memory layout more safely
+pub fn table_info(x: SEXP) -> Option<TableInfo> {
     if r_is_data_frame(x) {
-        return df_info(x);
+        return df_info(x).ok();
     }
 
     if r_is_matrix(x) {
-        return mat_info(x);
+        return mat_info(x).ok();
     }
 
-    // TODO: better error message
-    anyhow::bail!("Unsupported type for data viewer");
+    None
 }
 
 pub fn df_info(x: SEXP) -> anyhow::Result<TableInfo> {
@@ -81,6 +83,14 @@ pub fn mat_dim(x: SEXP) -> TableDim {
     unsafe {
         let dims = Rf_getAttrib(x, R_DimSymbol);
 
+        // Might want to return an error instead, or take a strongly typed input
+        if r_typeof(dims) != INTSXP || r_length(dims) != 2 {
+            return TableDim {
+                num_rows: r_length(x) as i32,
+                num_cols: 1,
+            };
+        }
+
         TableDim {
             num_rows: INTEGER_ELT(dims, 0),
             num_cols: INTEGER_ELT(dims, 1),