diff --git a/src/SConscript b/src/SConscript
index 38ace12a179f34bf540f7c9bf2322ce449583772..b7e6159bb5d78bdef4d2b1e4c19e63fc1370f105 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -22,6 +22,7 @@ parsers = ['parsers/%s.c'%s for s in
['action',
'and',
'attr_bool',
+ 'bind',
'bits',
'butnot',
'ch',
diff --git a/src/hammer.h b/src/hammer.h
index b0ce75d20d74d65b8a64e5a25694ef8696acf4ad..716ab6d01aad890217e6c5583186bc8773aeff70 100644
--- a/src/hammer.h
+++ b/src/hammer.h
@@ -122,6 +122,19 @@ typedef struct HParseResult_ {
*/
typedef struct HBitWriter_ HBitWriter;
+typedef struct HCFChoice_ HCFChoice;
+typedef struct HRVMProg_ HRVMProg;
+typedef struct HParserVtable_ HParserVtable;
+
+// TODO: Make this internal
+typedef struct HParser_ {
+ const HParserVtable *vtable;
+ HParserBackend backend;
+ void* backend_data;
+ void *env;
+ HCFChoice *desugared; /* if the parser can be desugared, its desugared form */
+} HParser;
+
/**
* Type of an action to apply to an AST, used in the action() parser.
* It can be any (user-defined) function that takes a HParseResult*
@@ -141,18 +154,12 @@ typedef HParsedToken* (*HAction)(const HParseResult *p, void* user_data);
*/
typedef bool (*HPredicate)(HParseResult *p, void* user_data);
-typedef struct HCFChoice_ HCFChoice;
-typedef struct HRVMProg_ HRVMProg;
-typedef struct HParserVtable_ HParserVtable;
-
-// TODO: Make this internal
-typedef struct HParser_ {
- const HParserVtable *vtable;
- HParserBackend backend;
- void* backend_data;
- void *env;
- HCFChoice *desugared; /* if the parser can be desugared, its desugared form */
-} HParser;
+/**
+ * Type of a parser that depends on the result of a previous parser,
+ * used in h_bind(). The void* argument is passed through from h_bind() and can
+ * be used to arbitrarily parameterize the function further.
+ */
+typedef HParser* (*HContinuation)(const HParsedToken *x, void *env);
// {{{ Stuff for benchmarking
typedef struct HParserTestcase_ {
@@ -663,6 +670,17 @@ HAMMER_FN_DECL(HParser*, h_put_value, const HParser *p, const char* name);
*/
HAMMER_FN_DECL(HParser*, h_get_value, const char* name);
+/**
+ * Monadic bind for HParsers, i.e.:
+ * Sequencing where later parsers may depend on the result(s) of earlier ones.
+ *
+ * Run p and call the result x. Then run k(env,x). Fail if p fails or if
+ * k(env,x) fails.
+ *
+ * Result: the result of k(x,env).
+ */
+HAMMER_FN_DECL(HParser*, h_bind, const HParser *p, HContinuation k, void *env);
+
/**
* Free the memory allocated to an HParseResult when it is no longer needed.
*/
diff --git a/src/parsers/bind.c b/src/parsers/bind.c
new file mode 100644
index 0000000000000000000000000000000000000000..ccbf6da8cd5aa067fd6413e67e320bab8e92a49a
--- /dev/null
+++ b/src/parsers/bind.c
@@ -0,0 +1,42 @@
+#include "parser_internal.h"
+
+typedef struct {
+ const HParser *p;
+ HContinuation k;
+ void *env;
+} BindEnv;
+
+static HParseResult *parse_bind(void *be_, HParseState *state) {
+ BindEnv *be = be_;
+
+ HParseResult *res = h_do_parse(be->p, state);
+ if(!res)
+ return NULL;
+
+ HParser *kx = be->k(res->ast, be->env);
+ return h_do_parse(kx, state);
+}
+
+static const HParserVtable bind_vt = {
+ .parse = parse_bind,
+ .isValidRegular = h_false,
+ .isValidCF = h_false,
+ .compile_to_rvm = h_not_regular,
+};
+
+HParser *h_bind(const HParser *p, HContinuation k, void *env)
+{
+ return h_bind__m(&system_allocator, p, k, env);
+}
+
+HParser *h_bind__m(HAllocator *mm__,
+ const HParser *p, HContinuation k, void *env)
+{
+ BindEnv *be = h_new(BindEnv, 1);
+
+ be->p = p;
+ be->k = k;
+ be->env = env;
+
+ return h_new_parser(mm__, &bind_vt, be);
+}
diff --git a/src/t_parser.c b/src/t_parser.c
index 191996cc838191dd07030fd045d56069af29892e..25495e34194b785cd3d713344e026aa4f0c4d2fc 100644
--- a/src/t_parser.c
+++ b/src/t_parser.c
@@ -568,6 +568,34 @@ static void test_permutation(gconstpointer backend) {
g_check_parse_failed(po2, be, "ccc", 3);
}
+static HParser *f_test_bind(const HParsedToken *p, void *env) {
+ uint8_t one = (uintptr_t)env;
+
+ assert(p);
+ assert(p->token_type == TT_SEQUENCE);
+
+ int v=0;
+ for(size_t i=0; i<p->seq->used; i++) {
+ assert(p->seq->elements[i]->token_type == TT_UINT);
+ v = v*10 + p->seq->elements[i]->uint - '0';
+ }
+
+ return h_ch(one - 1 + v);
+}
+static void test_bind(gconstpointer backend) {
+ HParserBackend be = (HParserBackend)GPOINTER_TO_INT(backend);
+ const HParser *digit = h_ch_range('0', '9');
+ const HParser *nat = h_many1(digit);
+ const HParser *p = h_bind(nat, f_test_bind, (void *)(uintptr_t)'a');
+
+ g_check_parse_match(p, be, "1a", 2, "u0x61");
+ g_check_parse_match(p, be, "2b", 2, "u0x62");
+ g_check_parse_match(p, be, "26z", 3, "u0x7a");
+ g_check_parse_failed(p, be, "1x", 2);
+ g_check_parse_failed(p, be, "29y", 3);
+ g_check_parse_failed(p, be, "@", 1);
+}
+
void register_parser_tests(void) {
g_test_add_data_func("/core/parser/packrat/token", GINT_TO_POINTER(PB_PACKRAT), test_token);
g_test_add_data_func("/core/parser/packrat/ch", GINT_TO_POINTER(PB_PACKRAT), test_ch);
@@ -617,6 +645,7 @@ void register_parser_tests(void) {
g_test_add_data_func("/core/parser/packrat/endianness", GINT_TO_POINTER(PB_PACKRAT), test_endianness);
g_test_add_data_func("/core/parser/packrat/putget", GINT_TO_POINTER(PB_PACKRAT), test_put_get);
g_test_add_data_func("/core/parser/packrat/permutation", GINT_TO_POINTER(PB_PACKRAT), test_permutation);
+ g_test_add_data_func("/core/parser/packrat/bind", GINT_TO_POINTER(PB_PACKRAT), test_bind);
g_test_add_data_func("/core/parser/llk/token", GINT_TO_POINTER(PB_LLk), test_token);
g_test_add_data_func("/core/parser/llk/ch", GINT_TO_POINTER(PB_LLk), test_ch);