1 files changed, 53 insertions, 7 deletions

diff --git a/pit/src/native.c b/pit/src/native.c
index d0989a5..4dab09d 100644
--- a/pit/src/native.c
+++ b/pit/src/native.c
@@ -2,6 +2,8 @@
 #include <stdio.h>
 #include <string.h>
 
+#include <sys/stat.h>
+
 #include <lcq/pit/lexer.h>
 #include <lcq/pit/parser.h>
 #include <lcq/pit/runtime.h>
@@ -101,7 +103,7 @@ pit_value pit_value_bytes_new_file(pit_runtime *rt, char *path) {
 /* check invariants - these should always hold between top-level evaluations! */
 static void check_invariants(pit_runtime *rt) {
     if (rt->saved_bindings->next != 0) {
-        pit_error(rt, "leaked saved_bindings memory! %ld", rt->result_stack->next);
+        pit_error(rt, "leaked saved_bindings memory! %ld", rt->saved_bindings->next);
     }
     if (rt->expr_stack->next != 0) {
         pit_error(rt, "leaked expr_stack memory! %ld", rt->expr_stack->next);
@@ -110,7 +112,7 @@ static void check_invariants(pit_runtime *rt) {
         pit_error(rt, "leaked result_stack memory! %ld", rt->result_stack->next);
     }
     if (rt->compilation_stack->next != 0) {
-        pit_error(rt, "leaked compilation_stack memory! %ld", rt->result_stack->next);
+        pit_error(rt, "leaked compilation_stack memory! %ld", rt->compilation_stack->next);
     }
     if (rt->traversal->next != 0) {
         pit_error(rt, "leaked traversal memory! %ld", rt->traversal->next);
@@ -146,7 +148,6 @@ void pit_repl(pit_runtime *rt) {
     size_t bufcap = 8;
     char *buf = malloc(bufcap);
     i64 len = 0;
-    pit_runtime_freeze(rt);
     check_invariants(rt); if (pit_runtime_print_error(rt)) exit(1);
     setbuf(stdout, NULL);
     printf("> ");
@@ -223,13 +224,58 @@ static pit_value impl_princ(pit_runtime *rt, pit_value args, void *data) {
 static pit_value impl_load(pit_runtime *rt, pit_value args, void *data) {
     (void) data;
     pit_value path = pit_value_cons_car(rt, args);
-    char pathbuf[1024] = {0};
-    i64 len = pit_value_bytes_copy(rt, path, (u8 *) pathbuf, sizeof(pathbuf) - 1);
+    char relbuf[1024] = {0};
+    i64 len = pit_value_bytes_copy(rt, path, (u8 *) relbuf, sizeof(relbuf) - 1);
     if (len < 0) { pit_error(rt, "path was not a string"); return PIT_NIL; }
-    pathbuf[len] = 0;
-    return pit_load_file(rt, pathbuf);
+    relbuf[len] = 0;
+    if (relbuf[0] != '/') {
+        /* if this is a relative path... */
+        char absbuf[1024] = {0};
+        struct stat sb;
+        pit_value lp = pit_symtab_get(rt, pit_symtab_intern_cstr(rt, "*load-path*"));
+        /* ...first search against the current directory... */
+        if (stat(relbuf, &sb) == 0) {
+            return pit_load_file(rt, relbuf);
+        }
+        while (lp != PIT_NIL) {
+            /* ...and then the *load-path* variable */
+            pit_value ent = pit_value_cons_car(rt, lp);
+            i64 elen = pit_value_bytes_copy(rt, ent, (u8 *) absbuf, sizeof(absbuf) - 1);
+            if (elen > 0 && absbuf[elen - 1] != '/') absbuf[elen++] = '/';
+            i64 remaining = (i64) sizeof(absbuf) - elen - 1;
+            if (len > remaining) {
+                pit_error(rt, "not enough space in buffer to construct file load path");
+                return PIT_NIL;
+            }
+            pit_libc_string_memcpy((u8 *) &absbuf[elen], (u8 *) relbuf, (size_t) len);
+            absbuf[elen + len] = 0;
+            if (stat(absbuf, &sb) == 0) {
+                /* the file exists, this is the one we load! */
+                return pit_load_file(rt, absbuf);
+            }
+            lp = pit_value_cons_cdr(rt, lp);
+        }
+        /* we didn't find the file anywhere :( */
+        pit_error(rt, "failed to load file: %s", relbuf);
+        return PIT_NIL;
+    } else {
+        /* this is an absolute path, so simply load it */
+        return pit_load_file(rt, relbuf);
+    }
 }
 void pit_install_library_io(pit_runtime *rt) {
+    pit_value load_path = PIT_NIL;
+    char *lp = getenv("PIT_LOAD_PATH");
+    if (lp != NULL) {
+        char *section = strtok(lp, ":");
+        while (section) {
+            load_path = pit_value_cons(rt, pit_value_bytes_new_cstr(rt, section), load_path);
+            section = strtok(NULL, ":");
+        }
+        load_path = pit_value_list_reverse(rt, load_path);
+    }
+    /* variables */
+    pit_symtab_set(rt, pit_symtab_intern_cstr(rt, "*load-path*"), load_path);
     /* diagnostics */
     pit_symtab_fset(rt, pit_symtab_intern_cstr(rt, "diagnostics!"), pit_value_nativefunc_new(rt, impl_diagnostics));
     /* stream IO */