Adds the code for the Let computation.

Still not in the parser, though.

3 files changed, 145 insertions, 0 deletions

diff --git a/src/core/src/tonkadur/fate/v1/lang/computation/Let.java b/src/core/src/tonkadur/fate/v1/lang/computation/Let.java
new file mode 100644
index 0000000..f5be874
--- /dev/null
+++ b/src/core/src/tonkadur/fate/v1/lang/computation/Let.java
@@ -0,0 +1,89 @@
+package tonkadur.fate.v1.lang.computation;
+
+import java.util.List;
+
+import tonkadur.functional.Cons;
+
+import tonkadur.parser.Origin;
+
+import tonkadur.fate.v1.lang.meta.ComputationVisitor;
+import tonkadur.fate.v1.lang.meta.Computation;
+
+import tonkadur.fate.v1.lang.Variable;
+
+import tonkadur.fate.v1.lang.type.Type;
+
+public class Let extends Computation
+{
+   /***************************************************************************/
+   /**** MEMBERS **************************************************************/
+   /***************************************************************************/
+   protected final Computation computation;
+   protected final List<Cons<Variable, Computation>> assignments;
+
+   /***************************************************************************/
+   /**** PROTECTED ************************************************************/
+   /***************************************************************************/
+
+   /***************************************************************************/
+   /**** PUBLIC ***************************************************************/
+   /***************************************************************************/
+   /**** Constructors *********************************************************/
+   public Let
+   (
+      final Origin origin,
+      final List<Cons<Variable, Computation>> assignments,
+      final Computation computation
+   )
+   {
+      super(origin, computation.get_type());
+
+      this.computation = computation;
+      this.assignments = assignments;
+   }
+
+   /**** Accessors ************************************************************/
+   @Override
+   public void get_visited_by (final ComputationVisitor cv)
+   throws Throwable
+   {
+      cv.visit_let(this);
+   }
+
+   public Computation get_computation ()
+   {
+      return computation;
+   }
+
+   public List<Cons<Variable, Computation>> get_assignments ()
+   {
+      return assignments;
+   }
+
+   /**** Misc. ****************************************************************/
+   @Override
+   public String toString ()
+   {
+      final StringBuilder sb = new StringBuilder();
+
+      sb.append("(Let (");
+
+      for (final Cons<Variable, Computation> assignment: assignments)
+      {
+         sb.append("(");
+         sb.append(assignment.get_car().get_type());
+         sb.append(" ");
+         sb.append(assignment.get_car().get_name());
+         sb.append(" ");
+         sb.append(assignment.get_cdr().toString());
+         sb.append(")");
+      }
+      sb.append(") ");
+
+      sb.append(computation.toString());
+
+      sb.append(")");
+
+      return sb.toString();
+   }
+}
diff --git a/src/core/src/tonkadur/fate/v1/lang/meta/ComputationVisitor.java b/src/core/src/tonkadur/fate/v1/lang/meta/ComputationVisitor.java
index 32fcee7..09b9135 100644
--- a/src/core/src/tonkadur/fate/v1/lang/meta/ComputationVisitor.java
+++ b/src/core/src/tonkadur/fate/v1/lang/meta/ComputationVisitor.java
@@ -49,6 +49,9 @@ public interface ComputationVisitor
    public void visit_lambda_evaluation (final LambdaEvaluation n)
    throws Throwable;
 
+   public void visit_let (final Let n)
+   throws Throwable;
+
    public void visit_newline (final Newline n)
    throws Throwable;
 
diff --git a/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/ComputationCompiler.java b/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/ComputationCompiler.java
index 5a06201..94e013d 100644
--- a/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/ComputationCompiler.java
+++ b/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/ComputationCompiler.java
@@ -1643,6 +1643,59 @@ implements tonkadur.fate.v1.lang.meta.ComputationVisitor
    }
 
    @Override
+   public void visit_let
+   (
+      final tonkadur.fate.v1.lang.computation.Let n
+   )
+   throws Throwable
+   {
+      final Collection<String> names;
+
+      names = new ArrayList<String>();
+
+      for
+      (
+         final
+            Cons
+            <
+               tonkadur.fate.v1.lang.Variable,
+               tonkadur.fate.v1.lang.meta.Computation
+            >
+            a:
+               n.get_assignments()
+      )
+      {
+         final String name;
+         final Register r;
+         final ComputationCompiler cc;
+
+         name = a.get_car().get_name();
+         r = reserve(TypeCompiler.compile(compiler, a.get_car().get_type()));
+
+         compiler.registers().bind(name, r);
+         names.add(name);
+
+         cc = new ComputationCompiler(compiler);
+
+         a.get_cdr().get_visited_by(cc);
+
+         assimilate(cc);
+
+         init_instructions.add
+         (
+            new SetValue(r.get_address(), cc.get_computation())
+         );
+      }
+
+      n.get_computation().get_visited_by(this);
+
+      for (final String name: names)
+      {
+         compiler.registers().unbind(name);
+      }
+   }
+
+   @Override
    public void visit_variable_reference
    (
       final tonkadur.fate.v1.lang.computation.VariableReference n