re-factor options handling of read_term into read_term_body (#1887)

src/machine/machine_state.rs

@@ -12,6 +12,7 @@ use crate::machine::machine_indices::*;
 use crate::machine::stack::*;
 use crate::machine::streams::*;
 use crate::parser::ast::*;
+use crate::read::TermWriteResult;
 use crate::types::*;
 
 use crate::parser::rug::Integer;
@@ -482,24 +483,7 @@ impl MachineState {
         }
     }
 
-    // Safety: the atom_tbl lives for the lifetime of the machine, as does the helper, so the ptr
-    // will always be valid.
-    pub fn read_term_from_user_input(&mut self, stream: Stream, indices: &mut IndexStore) -> CallResult {
-        let atoms_ptr = (&self.atom_tbl.table) as *const indexmap::IndexSet<Atom>;
-
-        if let Stream::Readline(ptr) = stream {
-            unsafe {
-                let readline = ptr.as_ptr().as_mut().unwrap();
-                readline.set_atoms_for_completion(atoms_ptr);
-                let ret = self.read_term(stream, indices);
-                return ret
-            }
-        }
-
-        unreachable!("Stream must be a Stream::Readline(_)")
-    }
-
-    pub fn read_term(&mut self, stream: Stream, indices: &mut IndexStore) -> CallResult {
+    pub fn read_term_body(&mut self, mut term_write_result: TermWriteResult) -> CallResult {
         fn push_var_eq_functors<'a>(
             heap: &mut Heap,
             iter: impl Iterator<Item = (&'a VarPtr, &'a HeapCellValue)>,
@@ -521,25 +505,6 @@ impl MachineState {
             list_of_var_eqs
         }
 
-        self.check_stream_properties(
-            stream,
-            StreamType::Text,
-            Some(self.registers[2]),
-            atom!("read_term"),
-            3,
-        )?;
-
-        if stream.past_end_of_stream() {
-            if EOFAction::Reset != stream.options().eof_action() {
-                return Ok(());
-            } else if self.fail {
-                return Ok(());
-            }
-        }
-
-        loop {
-            match self.read(stream, &indices.op_dir) {
-                Ok(mut term_write_result) => {
         let heap_loc = read_heap_cell!(self.heap[term_write_result.heap_loc],
             (HeapCellValueTag::PStr | HeapCellValueTag::PStrOffset) => {
                 pstr_loc_as_cell!(term_write_result.heap_loc)
@@ -633,6 +598,44 @@ impl MachineState {
 
         return Ok(unify_fn!(*self, var_names_offset, var_names_addr));
     }
+
+    // Safety: the atom_tbl lives for the lifetime of the machine, as does the helper, so the ptr
+    // will always be valid.
+    pub fn read_term_from_user_input(&mut self, stream: Stream, indices: &mut IndexStore) -> CallResult {
+        let atoms_ptr = (&self.atom_tbl.table) as *const indexmap::IndexSet<Atom>;
+
+        if let Stream::Readline(ptr) = stream {
+            unsafe {
+                let readline = ptr.as_ptr().as_mut().unwrap();
+                readline.set_atoms_for_completion(atoms_ptr);
+                let ret = self.read_term(stream, indices);
+                return ret
+            }
+        }
+
+        unreachable!("Stream must be a Stream::Readline(_)")
+    }
+
+    pub fn read_term(&mut self, stream: Stream, indices: &mut IndexStore) -> CallResult {
+        self.check_stream_properties(
+            stream,
+            StreamType::Text,
+            Some(self.registers[2]),
+            atom!("read_term"),
+            3,
+        )?;
+
+        if stream.past_end_of_stream() {
+            if EOFAction::Reset != stream.options().eof_action() {
+                return Ok(());
+            } else if self.fail {
+                return Ok(());
+            }
+        }
+
+        loop {
+            match self.read(stream, &indices.op_dir) {
+                Ok(term_write_result) => return self.read_term_body(term_write_result),
                 Err(err) => {
                     match err {
                         CompilationError::ParserError(e) if e.is_unexpected_eof() => {

src/machine/system_calls.rs

@@ -5816,7 +5816,7 @@ impl Machine {
             let term_write_result = match term_write_result {
                 Ok(term_write_result) => term_write_result,
                 Err(e) => {
-                    let stub = functor_stub(atom!("read_term_from_chars"), 2);
+                    let stub = functor_stub(atom!("read_from_chars"), 2);
                     let e = self.machine_st.session_error(SessionError::from(e));
 
                     return Err(self.machine_st.error_form(e, stub));
@@ -5837,8 +5837,31 @@ impl Machine {
     #[inline(always)]
     pub(crate) fn read_term_from_chars(&mut self) -> CallResult {
         if let Some(atom_or_string) = self.machine_st.value_to_str_like(self.machine_st.registers[1]) {
-            let stream = Stream::from_owned_string(atom_or_string.to_string(), &mut self.machine_st.arena);
-            self.machine_st.read_term(stream, &mut self.indices)
+            let chars = CharReader::new(ByteStream::from_string(atom_or_string.to_string()));
+            let mut parser = Parser::new(chars, &mut self.machine_st);
+            let op_dir = CompositeOpDir::new(&self.indices.op_dir, None);
+
+            let term_write_result = parser.read_term(&op_dir, Tokens::Default)
+                .map_err(CompilationError::from)
+                .and_then(|term| {
+                    write_term_to_heap(
+                        &term,
+                        &mut self.machine_st.heap,
+                        &mut self.machine_st.atom_tbl,
+                    )
+                });
+
+            let term_write_result = match term_write_result {
+                Ok(term_write_result) => term_write_result,
+                Err(e) => {
+                    let stub = functor_stub(atom!("read_term_from_chars"), 3);
+                    let e = self.machine_st.session_error(SessionError::from(e));
+
+                    return Err(self.machine_st.error_form(e, stub));
+                }
+            };
+
+            self.machine_st.read_term_body(term_write_result)
         } else {
             unreachable!()
         }