stm: Add stm import support.

3 files changed, 44 insertions, 14 deletions

diff --git a/stm/lexerfatfs.c b/stm/lexerfatfs.c
index 5dcaca1606..461fbb3709 100644
--- a/stm/lexerfatfs.c
+++ b/stm/lexerfatfs.c
@@ -7,7 +7,14 @@
 #include "lexer.h"
 #include "lexerfatfs.h"
 
-unichar file_buf_next_char(mp_lexer_file_buf_t *fb) {
+typedef struct _mp_lexer_file_buf_t {
+    FIL fp;
+    char buf[20];
+    uint16_t len;
+    uint16_t pos;
+} mp_lexer_file_buf_t;
+
+static unichar file_buf_next_char(mp_lexer_file_buf_t *fb) {
     if (fb->pos >= fb->len) {
         if (fb->len < sizeof(fb->buf)) {
             return MP_LEXER_CHAR_EOF;
@@ -24,13 +31,16 @@ unichar file_buf_next_char(mp_lexer_file_buf_t *fb) {
     return fb->buf[fb->pos++];
 }
 
-void file_buf_close(mp_lexer_file_buf_t *fb) {
+static void file_buf_close(mp_lexer_file_buf_t *fb) {
     f_close(&fb->fp);
+    m_del_obj(mp_lexer_file_buf_t, fb);
 }
 
-mp_lexer_t *mp_lexer_new_from_file(const char *filename, mp_lexer_file_buf_t *fb) {
+mp_lexer_t *mp_lexer_new_from_file(const char *filename) {
+    mp_lexer_file_buf_t *fb = m_new_obj(mp_lexer_file_buf_t);
     FRESULT res = f_open(&fb->fp, filename, FA_READ);
     if (res != FR_OK) {
+        m_del_obj(mp_lexer_file_buf_t, fb);
         return NULL;
     }
     UINT n;
@@ -40,7 +50,35 @@ mp_lexer_t *mp_lexer_new_from_file(const char *filename, mp_lexer_file_buf_t *fb
     return mp_lexer_new(filename, fb, (mp_lexer_stream_next_char_t)file_buf_next_char, (mp_lexer_stream_close_t)file_buf_close);
 }
 
+/******************************************************************************/
+// implementation of import
+
+#include "ff.h"
+
 mp_lexer_t *mp_import_open_file(qstr mod_name) {
-    printf("import not implemented\n");
+    vstr_t *vstr = vstr_new();
+    FRESULT res;
+
+    // look for module in src/
+    vstr_printf(vstr, "0:/src/%s.py", qstr_str(mod_name));
+    res = f_stat(vstr_str(vstr), NULL);
+    if (res == FR_OK) {
+        // found file
+        return mp_lexer_new_from_file(vstr_str(vstr)); // TODO does lexer need to copy the string? can we free it here?
+    }
+
+    // look for module in /
+    vstr_reset(vstr);
+    vstr_printf(vstr, "0:/%s.py", qstr_str(mod_name));
+    res = f_stat(vstr_str(vstr), NULL);
+    if (res == FR_OK) {
+        // found file
+        return mp_lexer_new_from_file(vstr_str(vstr)); // TODO does lexer need to copy the string? can we free it here?
+    }
+
+    // could not find file
+    vstr_free(vstr);
+    printf("import %s: could not find file in src/ or /\n", qstr_str(mod_name));
+
     return NULL;
 }
diff --git a/stm/lexerfatfs.h b/stm/lexerfatfs.h
index f1fe5ad485..55902a3006 100644
--- a/stm/lexerfatfs.h
+++ b/stm/lexerfatfs.h
@@ -1,8 +1 @@
-typedef struct _mp_lexer_file_buf_t {
-    FIL fp;
-    char buf[20];
-    uint16_t len;
-    uint16_t pos;
-} mp_lexer_file_buf_t;
-
-mp_lexer_t *mp_lexer_new_from_file(const char *filename, mp_lexer_file_buf_t *fb);
+mp_lexer_t *mp_lexer_new_from_file(const char *filename);
diff --git a/stm/main.c b/stm/main.c
index d8649f5797..4b6aaf76f9 100644
--- a/stm/main.c
+++ b/stm/main.c
@@ -455,8 +455,7 @@ void do_repl(void) {
 }
 
 bool do_file(const char *filename) {
-    mp_lexer_file_buf_t fb;
-    mp_lexer_t *lex = mp_lexer_new_from_file(filename, &fb);
+    mp_lexer_t *lex = mp_lexer_new_from_file(filename);
 
     if (lex == NULL) {
         printf("could not open file '%s' for reading\n", filename);