Added commands for printing to console and error generation.

Errors now print to stderr

functions.c

@@ -43,6 +43,7 @@ void lenv_add_builtin_funcs(lenv* env) {
     lenv_add_builtin(env, "head", builtin_head);
     lenv_add_builtin(env, "tail", builtin_tail);
     lenv_add_builtin(env, "if", builtin_if);
+    lenv_add_builtin(env, "print", builtin_print);
     
     //ENV Functions
     lenv_add_builtin(env, "def", builtin_def);
@@ -53,6 +54,7 @@ void lenv_add_builtin_funcs(lenv* env) {
     lenv_add_builtin(env, "\\", builtin_lambda);
     lenv_add_builtin(env, "load", builtin_load);
     lenv_add_builtin(env, "loadonce", builtin_loadonce);
+    lenv_add_builtin(env, "error", builtin_error);
 }
 
 char* builtin_op_strname(BUILTIN_OP_TYPE op) {
@@ -360,6 +362,14 @@ lval* builtin_if(lenv* env, lval* val) {
     return result;
     
 }
+lval* builtin_print(lenv* env, lval* val) {
+    for(int i = 0; i < val->cell_count; i++) {
+        lval_print(val->cell_list[i]);
+        putchar(' ');
+    }
+    putchar('\n');
+    return lval_ok();
+}
 //End List/Util functions
 
 //Start ENV Functions
@@ -512,4 +522,12 @@ lval* builtin_do_load(lenv* env, lval* val, BOOL loadonce) {
         return err;
     }
 }
+lval* builtin_error(lenv* env, lval* val) {
+    LASSERT_ARG_COUNT("error", val, val, 1);
+    LASSERT_TYPE("error", val, val->cell_list[0], LVAL_STR);
+    
+    lval* errorVal = lval_err_detail(LERR_USER, "%s", val->cell_list[0]->data.str);
+    lval_delete(val);
+    return errorVal;
+}
 //End ENV Functions

functions.h

@@ -58,6 +58,7 @@ extern "C" {
     lval* builtin_head(lenv* env, lval* val);
     lval* builtin_tail(lenv* env, lval* val);
     lval* builtin_if(lenv* env, lval* val);
+    lval* builtin_print(lenv* env, lval* val);
     
     //ENV Functions
     lval* builtin_envdef(lenv* env, lval* val, char* type);
@@ -69,6 +70,7 @@ extern "C" {
     lval* builtin_load(lenv* env, lval* val);
     lval* builtin_loadonce(lenv* env, lval* val);
     lval* builtin_do_load(lenv* env, lval* val, BOOL loadonce);
+    lval* builtin_error(lenv* env, lval* val);
     
 #ifdef	__cplusplus
 }

lang.c

@@ -10,7 +10,7 @@ mpc_ast_t* tokenize(char *input) {
     
     if (!mpc_parse("<stdin>", input,gLispy, &result)) {
         success = 0;
-        mpc_err_print(result.error);
+        mpc_err_print_to(result.error, stderr);
         mpc_err_delete(result.error);
     }
     

lval.h

@@ -26,7 +26,7 @@ typedef struct lval_func lval_func;
 #define LVAL_IS_FALSE(val) (val->type == LVAL_NUM && fabs(val->data.num) <= DBL_EPSILON)
 
 enum VAL_TYPE { LVAL_ERR, LVAL_NUM, LVAL_SYM, LVAL_FUNC, LVAL_S_EXPR, LVAL_Q_EXPR, LVAL_EXIT, LVAL_STR, LVAL_OK };
-enum VAL_ERROR { LERR_DIV_ZERO, LERR_BAD_OP, LERR_BAD_NUM, LERR_BAD_SYM, LERR_OTHER, LERR_SYNTAX };
+enum VAL_ERROR { LERR_DIV_ZERO, LERR_BAD_OP, LERR_BAD_NUM, LERR_BAD_SYM, LERR_OTHER, LERR_SYNTAX, LERR_USER };
 typedef enum VAL_TYPE VAL_TYPE;
 typedef enum VAL_ERROR VAL_ERROR;
 

main.c

@@ -128,18 +128,18 @@ void lval_print(lval* val) {
             }
             break;
         case LVAL_ERR:
-            printf("Error: ");
             switch(val->data.err.num) {
-                case LERR_DIV_ZERO: printf("Divide By Zero"); break;
-                case LERR_BAD_NUM: printf("Bad Number"); break;
-                case LERR_BAD_OP: printf("Invalid Operator"); break;
-                case LERR_BAD_SYM: printf("Unknown/Invalid Symbol"); break;
-                case LERR_OTHER: printf("Unknown Error"); break;
-                case LERR_SYNTAX: printf("Syntax Error"); break;
-                default: printf("Unknown Error"); break;
+                case LERR_DIV_ZERO: fprintf(stderr, "Divide By Zero"); break;
+                case LERR_BAD_NUM: fprintf(stderr,"Bad Number"); break;
+                case LERR_BAD_OP: fprintf(stderr,"Invalid Operator"); break;
+                case LERR_BAD_SYM: fprintf(stderr,"Unknown/Invalid Symbol"); break;
+                case LERR_OTHER: fprintf(stderr,"Unknown/Other Error"); break;
+                case LERR_SYNTAX: fprintf(stderr,"Syntax Error"); break;
+                case LERR_USER: fprintf(stderr,"Runtime Error"); break;
+                default: fprintf(stderr,"Unknown Error"); break;
             }
             if (val->data.err.detail != NULL) {
-                printf(", %s", val->data.err.detail);
+                fprintf(stderr,": %s", val->data.err.detail);
             }
             break;
     }