Abstract out back-end stream functionality from lexer.

1 files changed, 55 insertions, 0 deletions

diff --git a/unix/lexerunix.c b/unix/lexerunix.c
new file mode 100644
index 000000000..617d92bb8
--- /dev/null
+++ b/unix/lexerunix.c
@@ -0,0 +1,55 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "misc.h"
+#include "lexer.h"
+
+typedef struct _str_buf_t {
+    bool free;                  // free src_beg when done
+    const char *src_beg;        // beginning of source
+    const char *src_cur;        // current location in source
+    const char *src_end;        // end (exclusive) of source
+} str_buf_t;
+
+unichar str_buf_next_char(str_buf_t *sb) {
+    if (sb->src_cur < sb->src_end) {
+        return *sb->src_cur++;
+    } else {
+        return PY_LEXER_CHAR_EOF;
+    }
+}
+
+void str_buf_free(str_buf_t *sb) {
+    if (sb) {
+        if (sb->free) {
+            m_free((char*)sb->src_beg);
+        }
+        m_free(sb);
+    }
+}
+
+py_lexer_t *py_lexer_new_from_str_len(const char *src_name, const char *str, uint len, bool free_str) {
+    str_buf_t *sb = m_new(str_buf_t, 1);
+    sb->free = free_str;
+    sb->src_beg = str;
+    sb->src_cur = str;
+    sb->src_end = str + len;
+    return py_lexer_new(src_name, sb, (py_lexer_stream_next_char_t)str_buf_next_char, (py_lexer_stream_free_t)str_buf_free);
+}
+
+py_lexer_t *py_lexer_new_from_file(const char *filename) {
+    int fd = open(filename, O_RDONLY);
+    if (fd < 0) {
+        printf("cannot open file %s\n", filename);
+        return NULL;
+    }
+    uint size = lseek(fd, 0, SEEK_END);
+    lseek(fd, 0, SEEK_SET);
+    char *data = m_new(char, size);
+    read(fd, data, size);
+    close(fd);
+
+    return py_lexer_new_from_str_len(filename, data, size, true);
+}