Add type signature to def statements

Currently mandatory, may be optional once we have type inference.

1 files changed, 45 insertions, 0 deletions

diff --git a/src/nodes.h b/src/nodes.h
new file mode 100644
index 0000000..e6ceb50
--- /dev/null
+++ b/src/nodes.h
@@ -0,0 +1,45 @@
+#ifndef BDL_NODES_H
+#define BDL_NODES_H
+
+typedef enum NodeType {
+    NODE_BUILTIN,
+    NODE_NUMBER,
+    NODE_BOOL,
+    NODE_STRING,
+    NODE_SYMBOL,
+    NODE_DEF,
+} NodeType;
+
+typedef struct Node {
+    NodeType type;
+
+    union {
+        // Numbers.
+        struct {
+            bool negative;
+            size_t integral;
+            size_t fractional;
+        } number;
+
+        // String/symbol.
+        StringView string;
+
+        // Boolean.
+        bool boolean;
+
+        // Builtin primitive.
+        struct {
+            TokenType type;
+            struct Node **args;
+        } builtin;
+
+        // Variable definition.
+        struct {
+            struct Node *symbol;
+            struct Node *value;
+            StringView type;
+        } def;
+    };
+} Node;
+
+#endif // BDL_NODES_H