1 files changed, 72 insertions, 0 deletions
diff --git a/src/Spv.Generator/InstructionOperands.cs b/src/Spv.Generator/InstructionOperands.cs
new file mode 100644
index 00000000..c48b004f
--- /dev/null
+++ b/src/Spv.Generator/InstructionOperands.cs
@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+
+namespace Spv.Generator
+{
+    public struct InstructionOperands
+    {
+        private const int InternalCount = 5;
+
+        public int Count;
+        public Operand Operand1;
+        public Operand Operand2;
+        public Operand Operand3;
+        public Operand Operand4;
+        public Operand Operand5;
+        public Operand[] Overflow;
+
+        public Span<Operand> AsSpan()
+        {
+            if (Count > InternalCount)
+            {
+                return MemoryMarshal.CreateSpan(ref this.Overflow[0], Count);
+            }
+            else
+            {
+                return MemoryMarshal.CreateSpan(ref this.Operand1, Count);
+            }
+        }
+
+        public void Add(Operand operand)
+        {
+            if (Count < InternalCount)
+            {
+                MemoryMarshal.CreateSpan(ref this.Operand1, Count + 1)[Count] = operand;
+                Count++;
+            }
+            else
+            {
+                if (Overflow == null)
+                {
+                    Overflow = new Operand[InternalCount * 2];
+                    MemoryMarshal.CreateSpan(ref this.Operand1, InternalCount).CopyTo(Overflow.AsSpan());
+                }
+                else if (Count == Overflow.Length)
+                {
+                    Array.Resize(ref Overflow, Overflow.Length * 2);
+                }
+
+                Overflow[Count++] = operand;
+            }
+        }
+
+        private IEnumerable<Operand> AllOperands => new[] { Operand1, Operand2, Operand3, Operand4, Operand5 }
+            .Concat(Overflow ?? Array.Empty<Operand>())
+            .Take(Count);
+
+        public override string ToString()
+        {
+            return $"({string.Join(", ", AllOperands)})";
+        }
+
+        public string ToString(string[] labels)
+        {
+            var labeledParams = AllOperands.Zip(labels, (op, label) => $"{label}: {op}");
+            var unlabeledParams = AllOperands.Skip(labels.Length).Select(op => op.ToString());
+            var paramsToPrint = labeledParams.Concat(unlabeledParams);
+            return $"({string.Join(", ", paramsToPrint)})";
+        }
+    }
+}