1 files changed, 53 insertions, 0 deletions
diff --git a/ast.h b/ast.h
new file mode 100644
index 0000000..46c4b49
--- /dev/null
+++ b/ast.h
@@ -0,0 +1,53 @@
+#pragma once
+
+
+typedef enum ASTtype{
+	AST_LIST,
+	AST_WORD,
+	AST_NUMBER,
+	AST_SYMBOL,
+} ASTtype;
+
+
+typedef struct AST AST;
+
+typedef struct ASTlist{
+	int len;
+	AST **nodes;
+} ASTlist;
+
+typedef struct ASTword{
+	char *word;
+} ASTword;
+
+typedef struct ASTnumber{
+	double num;
+} ASTnumber;
+
+typedef struct ASTsymbol{
+	char *name;
+	int symid;
+	//if you're not the interpreter:
+	// if you just allocated the ASTsymbol yourself, set symid to -1;
+	// else, leave symid alone.
+} ASTsymbol;
+
+struct AST{
+	ASTtype type;
+	union {
+		ASTlist l;
+		ASTword w;
+		ASTnumber n;
+		ASTsymbol s;
+	};
+};
+
+
+void ast_free(AST *ast);
+
+AST* ast_copy(const AST *ast);
+
+AST* ast_list(int len,AST **nodes); //these convenience functions DO NOT copy their arguments
+AST* ast_word(char *word);
+AST* ast_number(double num);
+AST* ast_symbol(char *name);