Add runtime source

2 files changed, 40 insertions, 0 deletions

diff --git a/src/main/java/org/shedlang/compiler/sources/RuntimeSource.java b/src/main/java/org/shedlang/compiler/sources/RuntimeSource.java
new file mode 100644
index 00000000..83937493
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/sources/RuntimeSource.java
@@ -0,0 +1,39 @@
+package org.shedlang.compiler.sources;
+
+class RuntimeSource implements Source {
+    private RuntimeSource() {
+
+    }
+
+    static final RuntimeSource INSTANCE = new RuntimeSource();
+
+    @Override
+    public String contents() {
+        return "";
+    }
+
+    @Override
+    public String describe() {
+        return "(runtime)";
+    }
+
+    @Override
+    public Source start() {
+        return this;
+    }
+
+    @Override
+    public Source end() {
+        return this;
+    }
+
+    @Override
+    public Source at(int characterIndexStart, int characterIndexEnd) {
+        return this;
+    }
+
+    @Override
+    public Source to(Source end) {
+        return null;
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/sources/Sources.java b/src/main/java/org/shedlang/compiler/sources/Sources.java
index c815d1e0..5fb6a3b0 100644
--- a/src/main/java/org/shedlang/compiler/sources/Sources.java
+++ b/src/main/java/org/shedlang/compiler/sources/Sources.java
@@ -2,6 +2,7 @@ package org.shedlang.compiler.sources;
 
 public class Sources {
     public static Source NULL = NullSource.INSTANCE;
+    public static Source RUNTIME = RuntimeSource.INSTANCE;
 
     public static Source file(String filename, String contents) {
         return FileFragmentSource.file(filename, contents);