Adding an attribute type for the cols attribute of tgroup.

2 files changed, 13 insertions, 2 deletions

diff --git a/src/document_tree/attribute_types.rs b/src/document_tree/attribute_types.rs
index 4a9bd3d..e98118a 100644
--- a/src/document_tree/attribute_types.rs
+++ b/src/document_tree/attribute_types.rs
@@ -29,6 +29,16 @@ impl Default for FixedSpace { fn default() -> FixedSpace { FixedSpace::Preserve
 #[derive(Debug,PartialEq,Eq,Hash,Serialize)] pub struct ID(pub String);
 #[derive(Debug,PartialEq,Eq,Hash,Serialize)] pub struct NameToken(pub String);
 
+// The table DTD has the cols attribute of tgroup as required, but having
+// TableGroupCols not implement Default would leave no possible implementation
+// for TableGroup::with_children.
+#[derive(Debug,PartialEq,Eq,Hash,Serialize)] pub struct TableGroupCols(pub usize);
+impl Default for TableGroupCols {
+	fn default() -> Self {
+		TableGroupCols(0)
+	}
+}
+
 // no eq for f64
 #[derive(Debug,PartialEq,Serialize)]
 pub enum Measure {  // http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#length-units
@@ -125,6 +135,7 @@ macro_rules! impl_cannot_be_empty {
 	};
 }
 impl_cannot_be_empty!(target::Target);
+impl_cannot_be_empty!(TableGroupCols);
 
 impl<T> CanBeEmpty for Option<T> {
 	fn is_empty(&self) -> bool { self.is_none() }
diff --git a/src/document_tree/extra_attributes.rs b/src/document_tree/extra_attributes.rs
index 35f4b5a..bff9fb3 100644
--- a/src/document_tree/extra_attributes.rs
+++ b/src/document_tree/extra_attributes.rs
@@ -1,7 +1,7 @@
 use serde_derive::Serialize;
 
 use crate::target;
-use super::attribute_types::{CanBeEmpty,FixedSpace,ID,NameToken,AlignHV,AlignH,AlignV,TableAlignH,TableBorder,Measure,EnumeratedListType};
+use super::attribute_types::{CanBeEmpty,FixedSpace,ID,NameToken,AlignHV,AlignH,AlignV,TableAlignH,TableBorder,TableGroupCols,Measure,EnumeratedListType};
 
 pub trait ExtraAttributes<A> {
 	fn with_extra(extra: A) -> Self;
@@ -63,7 +63,7 @@ impl_extra!(SystemMessage { backrefs: Vec<ID>, level: Option<usize>, line: Optio
 impl_extra!(Figure { align: Option<AlignH>, width: Option<usize> });
 impl_extra!(Table { frame: Option<TableBorder>, colsep: Option<bool>, rowsep: Option<bool>, pgwide: Option<bool> });
 
-impl_extra!(TableGroup { cols: usize, colsep: Option<bool>, rowsep: Option<bool>, align: Option<TableAlignH> });
+impl_extra!(TableGroup { cols: TableGroupCols, colsep: Option<bool>, rowsep: Option<bool>, align: Option<TableAlignH> });
 impl_extra!(TableHead { valign: Option<AlignV> });
 impl_extra!(TableBody { valign: Option<AlignV> });
 impl_extra!(TableRow { rowsep: Option<bool>, valign: Option<AlignV> });