1 files changed, 69 insertions, 0 deletions
diff --git a/eval.c b/eval.c
new file mode 100644
index 0000000..4f4b1e2
--- /dev/null
+++ b/eval.c
@@ -0,0 +1,69 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include "parser.h"
+#include "builtin.h"
+#include "eval.h"
+
+int varcount = 0;
+luckyvar *variables[10000];
+
+int funccount= 0;
+luckytree *functions[10000];
+
+int argcount(luckyval *tree){
+	if (tree == NULL) return 0;
+	else return 1 + argcount(tree->nextelement);
+}
+
+bool checkargcount(luckytree *tree, int i){
+	return !(argcount(tree->arguments) == i);
+}
+
+void argcounterror(luckytree *tree, int expected){
+		if (checkargcount(tree, expected)) {
+			printf("expected %d args to function %s, got %d\n",expected, tree->function, argcount(tree->arguments));
+			exit(1);
+		}
+}
+
+luckyval *lookupvar(char *name){
+	for (int i = 0; i < 10000; i++){
+		if (variables[i] != NULL && strcmp(variables[i]->name, name) == 0){
+			return variables[i]->val;
+		}
+	}
+	printf("no such variable %s exists!\n", name);
+	exit(1);
+}
+
+luckyval *eval(luckytree *tree){
+	int i = 0;
+	for (luckyval *current = tree->arguments; i < argcount(tree->arguments); current = current->nextelement){
+		if (current->type == LUCKYTREE){
+			luckyval *var = malloc(sizeof(luckyval));
+			var = eval(current->tree);
+			memcpy(&current->d, &var->d, sizeof(double));
+			current->type = var->type;
+			free(var);
+		}
+		else if (strcmp(tree->function, "let") != 0) {
+			if (current->type == LUCKYVAR){
+				luckyval *tmp = lookupvar(current->var);		
+				memcpy(&current->d, &tmp->d, sizeof(double));
+				current->type = tmp->type;
+			}
+		}
+		i++;
+	}
+
+	luckyval *out = malloc(sizeof(luckyval));
+
+	if (arithmetic(tree, out)) return out;
+	else if (io(tree, out)) return out;
+	else if (variableops(tree, out)) return out;
+
+	printf("Unknown function!\n");
+	exit(1);
+}