From 976205f9da21acab80c7bc8ce2e0163d97084f11 Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Tue, 4 Jun 2013 22:14:06 +0200
Subject: [PATCH] hook up LALR backend stub
---
src/Makefile | 1 +
src/backends/lalr.c | 86 +++++++++++++++++++++++++++++++++++++++++++++
src/hammer.c | 1 +
src/hammer.h | 8 ++---
src/internal.h | 1 +
5 files changed, 93 insertions(+), 4 deletions(-)
create mode 100644 src/backends/lalr.c
diff --git a/src/Makefile b/src/Makefile
index 7fac881a..1a2bff35 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -28,6 +28,7 @@ PARSERS := \
BACKENDS := \
packrat \
llk \
+ lalr \
regex
HAMMER_PARTS := \
diff --git a/src/backends/lalr.c b/src/backends/lalr.c
new file mode 100644
index 00000000..22cd3890
--- /dev/null
+++ b/src/backends/lalr.c
@@ -0,0 +1,86 @@
+#include <assert.h>
+#include "../internal.h"
+#include "../cfgrammar.h"
+#include "../parsers/parser_internal.h"
+
+
+
+void h_lalr_free(HParser *parser)
+{
+ // XXX free data structures
+ parser->backend_data = NULL;
+ parser->backend = PB_PACKRAT;
+}
+
+
+/* LALR table generation */
+
+int h_lalr_compile(HAllocator* mm__, HParser* parser, const void* params)
+{
+ return -1;
+}
+
+
+/* LR driver */
+
+HParseResult *h_lr_parse(HAllocator* mm__, const HParser* parser, HInputStream* stream)
+{
+ return NULL;
+}
+
+
+
+
+HParserBackendVTable h__lalr_backend_vtable = {
+ .compile = h_lalr_compile,
+ .parse = h_lr_parse,
+ .free = h_lalr_free
+};
+
+
+
+
+// dummy!
+int test_lalr(void)
+{
+ /* for k=2:
+
+ S -> A | B
+ A -> X Y a
+ B -> Y b
+ X -> x | ''
+ Y -> y -- for k=3 use "yy"
+ */
+
+ // XXX make LALR example
+ HParser *X = h_optional(h_ch('x'));
+ HParser *Y = h_sequence(h_ch('y'), h_ch('y'), NULL);
+ HParser *A = h_sequence(X, Y, h_ch('a'), NULL);
+ HParser *B = h_sequence(Y, h_ch('b'), NULL);
+ HParser *p = h_choice(A, B, NULL);
+
+ HCFGrammar *g = h_cfgrammar(&system_allocator, p);
+
+ if(g == NULL) {
+ fprintf(stderr, "h_cfgrammar failed\n");
+ return 1;
+ }
+
+ h_pprint_grammar(stdout, g, 0);
+ // print states of the LR(0) automaton
+ // print LALR(1) table
+
+ if(h_compile(p, PB_LALR, NULL)) {
+ fprintf(stderr, "does not compile\n");
+ return 2;
+ }
+
+
+ HParseResult *res = h_parse(p, (uint8_t *)"xyya", 4);
+ if(res)
+ h_pprint(stdout, res->ast, 0, 2);
+ else
+ printf("no parse\n");
+
+ return 0;
+}
diff --git a/src/hammer.c b/src/hammer.c
index 5f941429..7d5b4e90 100644
--- a/src/hammer.c
+++ b/src/hammer.c
@@ -30,6 +30,7 @@ static HParserBackendVTable *backends[PB_MAX + 1] = {
&h__packrat_backend_vtable,
&h__regex_backend_vtable,
&h__llk_backend_vtable,
+ &h__lalr_backend_vtable,
};
diff --git a/src/hammer.h b/src/hammer.h
index 455684cc..a5ebcfff 100644
--- a/src/hammer.h
+++ b/src/hammer.h
@@ -34,11 +34,11 @@ typedef struct HParseState_ HParseState;
typedef enum HParserBackend_ {
PB_MIN = 0,
PB_PACKRAT = PB_MIN, // PB_MIN is always the default.
- PB_REGULAR, //
- PB_LLk, //
- PB_LALR, // Not Implemented
+ PB_REGULAR,
+ PB_LLk,
+ PB_LALR,
PB_GLR, // Not Implemented
- PB_MAX = PB_LLk
+ PB_MAX = PB_LALR
} HParserBackend;
typedef enum HTokenType_ {
diff --git a/src/internal.h b/src/internal.h
index 926bf02a..01861f5e 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -219,6 +219,7 @@ struct HBitWriter_ {
// Backends {{{
extern HParserBackendVTable h__packrat_backend_vtable;
extern HParserBackendVTable h__llk_backend_vtable;
+extern HParserBackendVTable h__lalr_backend_vtable;
// }}}
// TODO(thequux): Set symbol visibility for these functions so that they aren't exported.
--
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