Make plain text exit condition not an exit matcher.

I think this condition needs to not exist deeper down the tree.

src/parser/plain_text.rs

@@ -1,30 +1,30 @@
+use nom::branch::alt;
+use nom::character::complete::anychar;
+use nom::combinator::peek;
 use nom::combinator::recognize;
+use nom::combinator::verify;
+use nom::multi::many_till;
 
 use super::object::PlainText;
 use super::Context;
-use crate::error::CustomError;
-use crate::error::MyError;
 use crate::error::Res;
-use crate::parser::exiting::ExitClass;
 use crate::parser::object_parser::any_object_except_plain_text;
-use crate::parser::parser_context::ContextElement;
-use crate::parser::parser_context::ExitMatcherNode;
 use crate::parser::parser_with_context::parser_with_context;
-use crate::parser::util::text_until_exit;
+use crate::parser::util::exit_matcher_parser;
 
 #[tracing::instrument(ret, level = "debug")]
 pub fn plain_text<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, PlainText<'s>> {
-    if input.len() == 0 {
-        return Err(nom::Err::Error(CustomError::MyError(MyError(
-            "Zero input length to plain_text.",
-        ))));
-    }
-    let parser_context =
-        context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
-            class: ExitClass::Beta,
-            exit_matcher: &plain_text_end,
-        }));
-    let (remaining, source) = text_until_exit(&parser_context, input)?;
+    let (remaining, source) = recognize(verify(
+        many_till(
+            anychar,
+            peek(alt((
+                parser_with_context!(exit_matcher_parser)(context),
+                parser_with_context!(plain_text_end)(context),
+            ))),
+        ),
+        |(children, _exit_contents)| !children.is_empty(),
+    ))(input)?;
+
     Ok((remaining, PlainText { source }))
 }