2 files changed, 39 insertions, 1 deletions

diff --git a/interpreter.c b/interpreter.c
index 5a3d66a..333b8c9 100644
--- a/interpreter.c
+++ b/interpreter.c
@@ -80,3 +80,41 @@ void inter_destroy(InterState *is){
 	for(int i=0;i<is->ss.len;i++)free(is->ss.syms[i]);
 	free(is->ss.syms);
 }
+
+
+static void intern_symbols(InterState *is,AST *ast){
+	switch(ast->type){
+		case AST_LIST:
+			for(int i=0;i<ast->l.len;i++)intern_symbols(is,ast->l.nodes[i]);
+			break;
+
+		case AST_SYMBOL:{
+			if(ast->s.symid>=0&&ast->s.symid<is->ss.len&&strcmp(ast->s.name,is->ss.syms[ast->s.symid])==0){
+				break;
+			}
+			int i;
+			for(i=0;i<is->ss.len;i++){
+				if(strcmp(is->ss.syms[i],ast->s.name)==0)break;
+			}
+			if(i<is->ss.len){
+				ast->s.symid=i;
+				break;
+			}
+			if(is->ss.len==is->ss.sz){
+				is->ss.sz*=2;
+				is->ss.syms=realloc(is->ss.syms,is->ss.sz,char*);
+			}
+			is->ss.syms[is->ss.len++]=copystring(ast->s.name);
+			break;
+		}
+
+		case AST_WORD:
+		case AST_NUMBER:
+		case AST_STRING:
+			break;
+	}
+}
+
+void inter_runcode(InterState *is,AST *ast){
+	intern_symbols(is,ast);
+}
diff --git a/interpreter.h b/interpreter.h
index 66edce0..e643494 100644
--- a/interpreter.h
+++ b/interpreter.h
@@ -7,4 +7,4 @@ typedef struct InterState InterState;
 
 InterState* inter_make(void);
 void inter_destroy(InterState *is);
-void inter_runcode(AST *ast); //updates symbol id's
+void inter_runcode(InterState *is,AST *ast); //updates symbol id's