1 files changed, 76 insertions, 0 deletions
diff --git a/comp/dump.go b/comp/dump.go
new file mode 100644
index 0000000..865216b
--- /dev/null
+++ b/comp/dump.go
@@ -0,0 +1,76 @@
+package comp
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// Dump represents the state of a data dump.
+type Dump struct {
+	Values []*DumpValue
+}
+
+// DumpValue is a value of a dump state.
+type DumpValue struct {
+	Index int
+	Name  string
+	Kind  int
+	Type  string
+	Value any
+}
+
+// Dump creates a snapshot of the execution state of global variables.
+// This method is specifically implemented in the Compiler to minimize the coupling between
+// the dump format and other components. By situating the dump logic in the Compiler,
+// it relies solely on the program being executed and the indexing algorithm used for ordering variables
+// (currently, this is an integer that corresponds to the order of variables in the program).
+// This design choice allows the Virtual Machine (VM) to evolve its memory management strategies
+// without compromising backward compatibility with dumps generated by previous versions.
+func (c *Compiler) Dump() *Dump {
+	dict := c.symbolsByIndex()
+	dv := make([]*DumpValue, len(c.Data))
+	for i, d := range c.Data {
+		e := dict[i]
+		dv[i] = &DumpValue{
+			Index: e.Index,
+			Name:  e.name,
+			Kind:  int(e.Kind),
+			Type:  e.Type.Name,
+			Value: d.Interface(),
+		}
+	}
+	return &Dump{Values: dv}
+}
+
+// ApplyDump sets previously saved dump, restoring the state of global variables.
+func (c *Compiler) ApplyDump(d *Dump) error {
+	dict := c.symbolsByIndex()
+	for _, dv := range d.Values {
+		// do all the checks to be sure we are applying the correct values
+		e, ok := dict[dv.Index]
+		if !ok {
+			return fmt.Errorf("entry not found on index %d", dv.Index)
+		}
+
+		if dv.Name != e.name ||
+			dv.Type != e.Type.Name ||
+			dv.Kind != int(e.Kind) {
+			return fmt.Errorf("entry with index %d does not match with provided entry. "+
+				"dumpValue: %s, %s, %d. memoryValue: %s, %s, %d",
+				dv.Index,
+				dv.Name, dv.Type, dv.Kind,
+				e.name, e.Type, e.Kind)
+		}
+
+		if dv.Index >= len(c.Data) {
+			return fmt.Errorf("index (%d) bigger than memory (%d)", dv.Index, len(c.Data))
+		}
+
+		if !c.Data[dv.Index].CanSet() {
+			return fmt.Errorf("value %v cannot be set", dv.Value)
+		}
+
+		c.Data[dv.Index].Set(reflect.ValueOf(dv.Value))
+	}
+	return nil
+}