Implement multiline and hints support

[linenoise.git] / stringbuf.h

diff --git a/stringbuf.h b/stringbuf.h
new file mode 100644 (file)
index 0000000..8a04622
--- /dev/null
+++ b/stringbuf.h
@@ -0,0 +1,133 @@
+#ifndef STRINGBUF_H
+#define STRINGBUF_H
+
+/* (c) 2017 Workware Systems Pty Ltd  -- All Rights Reserved */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @file
+ * A stringbuf is a resizing, null terminated string buffer.
+ *
+ * The buffer is reallocated as necessary.
+ *
+ * In general it is *not* OK to call these functions with a NULL pointer
+ * unless stated otherwise.
+ *
+ * If USE_UTF8 is defined, supports utf8.
+ */
+
+/**
+ * The stringbuf structure should not be accessed directly.
+ * Use the functions below.
+ */
+typedef struct {
+       int remaining;  /**< Allocated, but unused space */
+       int last;               /**< Index of the null terminator (and thus the length of the string) */
+#ifdef USE_UTF8
+       int chars;              /**< Count of characters */
+#endif
+       char *data;             /**< Allocated memory containing the string or NULL for empty */
+} stringbuf;
+
+/**
+ * Allocates and returns a new stringbuf with no elements.
+ */
+stringbuf *sb_alloc(void);
+
+/**
+ * Frees a stringbuf.
+ * It is OK to call this with NULL.
+ */
+void sb_free(stringbuf *sb);
+
+/**
+ * Returns an allocated copy of the stringbuf
+ */
+stringbuf *sb_copy(stringbuf *sb);
+
+/**
+ * Returns the length of the buffer.
+ * 
+ * Returns 0 for both a NULL buffer and an empty buffer.
+ */
+static inline int sb_len(stringbuf *sb) {
+       return sb->last;
+}
+
+/**
+ * Returns the utf8 character length of the buffer.
+ * 
+ * Returns 0 for both a NULL buffer and an empty buffer.
+ */
+static inline int sb_chars(stringbuf *sb) {
+#ifdef USE_UTF8
+       return sb->chars;
+#else
+       return sb->last;
+#endif
+}
+
+/**
+ * Appends a null terminated string to the stringbuf
+ */
+void sb_append(stringbuf *sb, const char *str);
+
+/**
+ * Like sb_append() except does not require a null terminated string.
+ * The length of 'str' is given as 'len'
+ *
+ * Note that in utf8 mode, characters will *not* be counted correctly
+ * if a partial utf8 sequence is added with sb_append_len()
+ */
+void sb_append_len(stringbuf *sb, const char *str, int len);
+
+/**
+ * Returns a pointer to the null terminated string in the buffer.
+ *
+ * Note this pointer only remains valid until the next modification to the
+ * string buffer.
+ *
+ * The returned pointer can be used to update the buffer in-place
+ * as long as care is taken to not overwrite the end of the buffer.
+ */
+static inline char *sb_str(const stringbuf *sb)
+{
+       return sb->data;
+}
+
+/**
+ * Inserts the given string *before* (zero-based) 'index' in the stringbuf.
+ * If index is past the end of the buffer, the string is appended,
+ * just like sb_append()
+ */
+void sb_insert(stringbuf *sb, int index, const char *str);
+
+/**
+ * Delete 'len' bytes in the string at the given index.
+ *
+ * Any bytes past the end of the buffer are ignored.
+ * The buffer remains null terminated.
+ *
+ * If len is -1, deletes to the end of the buffer.
+ */
+void sb_delete(stringbuf *sb, int index, int len);
+
+/**
+ * Clear to an empty buffer.
+ */
+void sb_clear(stringbuf *sb);
+
+/**
+ * Return an allocated copy of buffer and frees 'sb'.
+ *
+ * If 'sb' is empty, returns an allocated copy of "".
+ */
+char *sb_to_string(stringbuf *sb);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif