Add a lexer for JSON

Our JSON parser is a three stage parser.  The first stage tokenizes the stream
into a set of lexical tokens.  Since the lexical grammar is regular, we can
use a finite state machine to model it.  The state machine will emit tokens
as they are identified.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/json-lexer.h b/json-lexer.h
new file mode 100644
index 0000000000..3b50c4634b
--- /dev/null
+++ b/json-lexer.h
@@ -0,0 +1,50 @@
+/*
+ * JSON lexer
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_JSON_LEXER_H
+#define QEMU_JSON_LEXER_H
+
+#include "qstring.h"
+#include "qlist.h"
+
+typedef enum json_token_type {
+    JSON_OPERATOR = 100,
+    JSON_INTEGER,
+    JSON_FLOAT,
+    JSON_KEYWORD,
+    JSON_STRING,
+    JSON_ESCAPE,
+    JSON_SKIP,
+} JSONTokenType;
+
+typedef struct JSONLexer JSONLexer;
+
+typedef void (JSONLexerEmitter)(JSONLexer *, QString *, JSONTokenType, int x, int y);
+
+struct JSONLexer
+{
+    JSONLexerEmitter *emit;
+    int state;
+    QString *token;
+    int x, y;
+};
+
+void json_lexer_init(JSONLexer *lexer, JSONLexerEmitter func);
+
+int json_lexer_feed(JSONLexer *lexer, const char *buffer, size_t size);
+
+int json_lexer_flush(JSONLexer *lexer);
+
+void json_lexer_destroy(JSONLexer *lexer);
+
+#endif