1 files changed, 71 insertions, 0 deletions
diff --git a/src/parse_productions.h b/src/parse_productions.h
new file mode 100644
index 00000000..df3ae9c9
--- /dev/null
+++ b/src/parse_productions.h
@@ -0,0 +1,71 @@
+/**\file parse_tree.h
+
+    Programmatic representation of fish code.
+*/
+
+#ifndef FISH_PARSE_TREE_CONSTRUCTION_H
+#define FISH_PARSE_TREE_CONSTRUCTION_H
+
+#include "parse_tree.h"
+#include <inttypes.h>
+
+namespace parse_productions
+{
+
+#define MAX_PRODUCTIONS 5
+#define MAX_SYMBOLS_PER_PRODUCTION 6
+
+typedef uint32_t production_tag_t;
+
+/* A production is an array of unsigned char. Symbols are encoded directly as their symbol value. Keywords are encoded with an offset of LAST_TOKEN_OR_SYMBOL + 1. So essentially we glom together keywords and symbols. */
+typedef uint8_t production_element_t;
+
+/* An index into a production option list */
+typedef uint8_t production_option_idx_t;
+
+/* A production is an array of production elements */
+typedef production_element_t const production_t[MAX_SYMBOLS_PER_PRODUCTION];
+
+/* A production options is an array of (possible) productions */
+typedef production_t production_options_t[MAX_PRODUCTIONS];
+
+/* Resolve the type from a production element */
+inline parse_token_type_t production_element_type(production_element_t elem)
+{
+    if (elem > LAST_TOKEN_OR_SYMBOL)
+    {
+        return parse_token_type_string;
+    }
+    else
+    {
+        return static_cast<parse_token_type_t>(elem);
+    }
+}
+
+/* Resolve the keyword from a production element */
+inline parse_keyword_t production_element_keyword(production_element_t elem)
+{
+    if (elem > LAST_TOKEN_OR_SYMBOL)
+    {
+        // First keyword is LAST_TOKEN_OR_SYMBOL + 1
+        return static_cast<parse_keyword_t>(elem - LAST_TOKEN_OR_SYMBOL - 1);
+    }
+    else
+    {
+        return parse_keyword_none;
+    }
+}
+
+/* Check if an element is valid */
+inline bool production_element_is_valid(production_element_t elem)
+{
+    return elem != token_type_invalid;
+}
+
+/* Fetch a production. We are passed two input tokens. The first input token is guaranteed to not be invalid; the second token may be invalid if there's no more tokens. */
+const production_t *production_for_token(parse_token_type_t node_type, const parse_token_t &input1, const parse_token_t &input2, production_option_idx_t *out_which_production, wcstring *out_error_text);
+
+}
+
+
+#endif