Working on the merge operator...

4 files changed, 37 insertions, 21 deletions

diff --git a/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4 b/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4
index c2ed078..10bb692 100644
--- a/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4
+++ b/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4
@@ -98,6 +98,12 @@ INDEXED_MERGE_TO_LIST_KW : L_PAREN 'indexed'US'merge'US'to'US'list' SEP+;
 INDEXED_MERGE_TO_SET_KW : L_PAREN 'indexed'US'merge'US'to'US'set' SEP+;
 IMP_MERGE_KW : L_PAREN 'merge!' SEP+;
 IMP_INDEXED_MERGE_KW : L_PAREN 'indexed'US'merge!' SEP+;
+SAFE_MERGE_TO_LIST_KW : L_PAREN 'safe'US'merge'US'to'US'list' SEP+;
+SAFE_MERGE_TO_SET_KW : L_PAREN 'safe'US'merge'US'to'US'set' SEP+;
+SAFE_INDEXED_MERGE_TO_LIST_KW : L_PAREN (('safe'US'indexed')|('indexed'US'safe'))US'merge'US'to'US'list' SEP+;
+SAFE_INDEXED_MERGE_TO_SET_KW : L_PAREN (('safe'US'indexed')|('indexed'US'safe'))US'merge'US'to'US'set' SEP+;
+SAFE_IMP_MERGE_KW : L_PAREN 'safe'US'merge!' SEP+;
+SAFE_IMP_INDEXED_MERGE_KW : L_PAREN (('indexed'US'safe')|('safe'US'indexed'))US'merge!' SEP+;
 NEWLINE_KW: L_PAREN 'newline)';
 NEW_KW: L_PAREN ('new'|'reserve'|'create') SEP+;
 NOT_KW: L_PAREN ('not'|'~'|'!') SEP+;
diff --git a/src/core/src/tonkadur/fate/v1/parser/FateParser.g4 b/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
index 2ea8bc4..4d791e3 100644
--- a/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
+++ b/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
@@ -1044,7 +1044,7 @@ returns [Instruction result]
          );
    }
 
-   | IMP_MERGE_KW
+   | SAFE_IMP_MERGE_KW
       fun=non_text_value WS+
       def0=value WS+
       value_reference WS+
@@ -1057,8 +1057,8 @@ returns [Instruction result]
          (
             CONTEXT.get_origin_at
             (
-               ($IMP_MERGE_KW.getLine()),
-               ($IMP_MERGE_KW.getCharPositionInLine())
+               ($SAFE_IMP_MERGE_KW.getLine()),
+               ($SAFE_IMP_MERGE_KW.getCharPositionInLine())
             ),
             ($fun.result),
             ($value_reference.result),
@@ -1069,7 +1069,7 @@ returns [Instruction result]
          );
    }
 
-   | IMP_MERGE_KW
+   | SAFE_IMP_MERGE_KW
       fun=non_text_value WS+
       def0=value WS+
       value_reference WS+
@@ -1083,8 +1083,8 @@ returns [Instruction result]
          (
             CONTEXT.get_origin_at
             (
-               ($IMP_MERGE_KW.getLine()),
-               ($IMP_MERGE_KW.getCharPositionInLine())
+               ($SAFE_IMP_MERGE_KW.getLine()),
+               ($SAFE_IMP_MERGE_KW.getCharPositionInLine())
             ),
             ($fun.result),
             ($value_reference.result),
@@ -4392,7 +4392,7 @@ returns [Computation result]
          );
    }
 
-   | MERGE_TO_LIST_KW
+   | SAFE_MERGE_TO_LIST_KW
          fun=non_text_value WS+
          def0=value WS+
          inv0=non_text_value WS+
@@ -4405,8 +4405,8 @@ returns [Computation result]
          (
             CONTEXT.get_origin_at
             (
-               ($MERGE_TO_LIST_KW.getLine()),
-               ($MERGE_TO_LIST_KW.getCharPositionInLine())
+               ($SAFE_MERGE_TO_LIST_KW.getLine()),
+               ($SAFE_MERGE_TO_LIST_KW.getCharPositionInLine())
             ),
             ($fun.result),
             ($inv0.result),
@@ -4418,7 +4418,7 @@ returns [Computation result]
          );
    }
 
-   | MERGE_TO_LIST_KW
+   | SAFE_MERGE_TO_LIST_KW
          fun=non_text_value WS+
          def0=value WS+
          inv0=non_text_value WS+
@@ -4432,8 +4432,8 @@ returns [Computation result]
          (
             CONTEXT.get_origin_at
             (
-               ($MERGE_TO_LIST_KW.getLine()),
-               ($MERGE_TO_LIST_KW.getCharPositionInLine())
+               ($SAFE_MERGE_TO_LIST_KW.getLine()),
+               ($SAFE_MERGE_TO_LIST_KW.getCharPositionInLine())
             ),
             ($fun.result),
             ($inv0.result),
@@ -4539,7 +4539,7 @@ returns [Computation result]
          );
    }
 
-   | MERGE_TO_SET_KW
+   | SAFE_MERGE_TO_SET_KW
          fun=non_text_value WS+
          def0=value WS+
          inv0=non_text_value WS+
@@ -4552,8 +4552,8 @@ returns [Computation result]
          (
             CONTEXT.get_origin_at
             (
-               ($MERGE_TO_SET_KW.getLine()),
-               ($MERGE_TO_SET_KW.getCharPositionInLine())
+               ($SAFE_MERGE_TO_SET_KW.getLine()),
+               ($SAFE_MERGE_TO_SET_KW.getCharPositionInLine())
             ),
             ($fun.result),
             ($inv0.result),
@@ -4565,7 +4565,7 @@ returns [Computation result]
          );
    }
 
-   | MERGE_TO_SET_KW
+   | SAFE_MERGE_TO_SET_KW
          fun=non_text_value WS+
          def0=value WS+
          inv0=non_text_value WS+
@@ -4579,8 +4579,8 @@ returns [Computation result]
          (
             CONTEXT.get_origin_at
             (
-               ($MERGE_TO_SET_KW.getLine()),
-               ($MERGE_TO_SET_KW.getCharPositionInLine())
+               ($SAFE_MERGE_TO_SET_KW.getLine()),
+               ($SAFE_MERGE_TO_SET_KW.getCharPositionInLine())
             ),
             ($fun.result),
             ($inv0.result),
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 2587769..9fb288d 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
@@ -2951,7 +2951,7 @@ implements tonkadur.fate.v1.lang.meta.ComputationVisitor
    )
    throws Throwable
    {
-      if (n.get_default_a() == null)
+      if (n.get_default_a() != null)
       {
          visit_merge_with_defaults(n);
 
diff --git a/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/InstructionCompiler.java b/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/InstructionCompiler.java
index 147f2f1..2f82d3c 100644
--- a/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/InstructionCompiler.java
+++ b/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/InstructionCompiler.java
@@ -890,10 +890,9 @@ implements tonkadur.fate.v1.lang.meta.InstructionVisitor
    )
    throws Throwable
    {
-      /* TODO: handle default values. */
       /* This is one dangerous operation to do in-place, so we don't. */
 
-      if (n.get_default_a() == null)
+      if (n.get_default_a() != null)
       {
          visit_merge_with_defaults(n);
          return;
@@ -938,6 +937,17 @@ implements tonkadur.fate.v1.lang.meta.InstructionVisitor
          new SetValue(holder.get_address(), collection_cc.get_computation())
       );
 
+      result.add
+      (
+         Clear.generate
+         (
+            compiler.registers(),
+            compiler.assembler(),
+            collection_cc.get_address()
+         )
+      );
+
+
       in_collection_b_cc = new ComputationCompiler(compiler);
 
       n.get_collection_in_b().get_visited_by(in_collection_b_cc);