diff --git a/examples/dns.c b/examples/dns.c
new file mode 100644
index 0000000000000000000000000000000000000000..027d675c5c5e80f2437882fa2b9adefbce70648d
--- /dev/null
+++ b/examples/dns.c
@@ -0,0 +1,85 @@
+#include "../hammer.h"
+
+bool is_zero(parse_result_t *p) {
+ return (0 == p->ast->uint);
+}
+
+bool validate_dns(parse_result_t *p) {
+
+}
+
+int main(int argc, char **argv) {
+
+ const parser_t dns_header = sequence(bits(16, false), // ID
+ bits(1, false), // QR
+ bits(4, false), // opcode
+ bits(1, false), // AA
+ bits(1, false), // TC
+ bits(1, false), // RD
+ bits(1, false), // RA
+ ignore(attr_bool(bits(3, false), is_zero)), // Z
+ bits(4, false), // RCODE
+ uint16(), // QDCOUNT
+ uint16(), // ANCOUNT
+ uint16(), // NSCOUNT
+ uint16(), // ARCOUNT
+ NULL);
+
+ const parser_t *dns_question = sequence(length_value(uint8(), uint8()), // QNAME
+ uint16(), // QTYPE
+ uint16(), // QCLASS
+ NULL);
+
+ const parser_t *letter = choice(range('a', 'z'),
+ range('A', 'Z'),
+ NULL);
+
+ const parser_t *let_dig = choice(letter,
+ range('0', '9'),
+ NULL);
+
+ const parser_t *ldh_str = many1(choice(let_dig,
+ ch('-'),
+ NULL));
+
+ const parser_t *label = sequence(letter,
+ optional(sequence(optional(ldh_str),
+ let_dig,
+ NULL)),
+ NULL);
+
+ /**
+ * You could write it like this ...
+ * parser_t *indirect_subdomain = indirect();
+ * const parser_t *subdomain = choice(label,
+ * sequence(indirect_subdomain,
+ * ch('.'),
+ * label,
+ * NULL),
+ * NULL);
+ * bind_indirect(indirect_subdomain, subdomain);
+ *
+ * ... but this is easier and equivalent
+ */
+
+ parser_t *subdomain = sepBy1(label, ch('.'));
+
+ const parser_t *domain = choice(subdomain,
+ ch(' '),
+ NULL);
+
+ const parser_t *dns_rr = sequence(domain, // NAME
+ uint16(), // TYPE
+ uint16(), // CLASS
+ uint32(), // TTL
+ length_value(uint16(), uint8()) // RDLENGTH+RDATA
+ NULL);
+
+
+ const parser_t *dns_message = attr_bool(sequence(dns_header,
+ dns_question,
+ many(dns_rr),
+ end_p(),
+ NULL),
+ validate_dns);
+}
diff --git a/src/hammer.c b/src/hammer.c
index eb418fe0fc408ac6ec77d672d0dba7295c7e0fa0..5bd1ae1008a7dfd75db81ff81e219a37c461b1f3 100644
--- a/src/hammer.c
+++ b/src/hammer.c
@@ -336,7 +336,31 @@ const parser_t* whitespace(const parser_t* p) {
return ret;
}
-const parser_t* action(const parser_t* p, const action_t a) { return &unimplemented; }
+typedef struct {
+ const parser_t *p;
+ action_t action;
+} parse_action_t;
+
+static parse_result_t* parse_action(void *env, parse_state_t *state) {
+ parse_action_t *a = (parse_action_t*)env;
+ if (a->p && a->action) {
+ parse_result_t *tmp = do_parse(a->p, state);
+ //parsed_token_t *tok = a->action(do_parse(a->p, state));
+ const parsed_token_t *tok = a->action(tmp);
+ return make_result(state, (parsed_token_t*)tok);
+ } else // either the parser's missing or the action's missing
+ return NULL;
+}
+
+const parser_t* action(const parser_t* p, const action_t a) {
+ parser_t *res = g_new(parser_t, 1);
+ res->fn = parse_action;
+ parse_action_t *env = g_new(parse_action_t, 1);
+ env->p = p;
+ env->action = a;
+ res->env = (void*)env;
+ return res;
+}
static parse_result_t* parse_charset(void *env, parse_state_t *state) {
uint8_t in = read_bits(&state->input_stream, 8, false);
@@ -783,7 +807,6 @@ const parser_t* epsilon_p() {
return res;
}
-
static parse_result_t* parse_indirect(void* env, parse_state_t* state) {
return do_parse(env, state);
}
@@ -798,7 +821,68 @@ parser_t* indirect() {
return res;
}
-const parser_t* attr_bool(const parser_t* p, attr_bool_t a) { return &unimplemented; }
+typedef struct {
+ const parser_t *p;
+ predicate_t pred;
+} attr_bool_t;
+
+static parse_result_t* parse_attr_bool(void *env, parse_state_t *state) {
+ attr_bool_t *a = (attr_bool_t*)env;
+ parse_result_t *res = do_parse(a->p, state);
+ if (res) {
+ if (a->pred(res))
+ return res;
+ else
+ return NULL;
+ } else
+ return NULL;
+}
+
+const parser_t* attr_bool(const parser_t* p, predicate_t pred) {
+ parser_t *res = g_new(parser_t, 1);
+ res->fn = parse_attr_bool;
+ attr_bool_t *env = g_new(attr_bool_t, 1);
+ env->p = p;
+ env->pred = pred;
+ res->env = (void*)env;
+ return res;
+}
+
+typedef struct {
+ const parser_t *length;
+ const parser_t *value;
+} lv_t;
+
+static parse_result_t* parse_length_value(void *env, parse_state_t *state) {
+ lv_t *lv = (lv_t*)env;
+ parse_result_t *len = do_parse(lv->length, state);
+ if (!len)
+ return NULL;
+ if (len->ast->token_type != TT_UINT)
+ errx(1, "Length parser must return an unsigned integer");
+ parser_t epsilon_local = {
+ .fn = parse_epsilon,
+ .env = NULL
+ };
+ repeat_t repeat = {
+ .p = lv->value,
+ .sep = &epsilon_local,
+ .count = len->ast->uint,
+ .min_p = false
+ };
+ return parse_many(&repeat, state);
+}
+
+const parser_t* length_value(const parser_t* length, const parser_t* value) {
+ parser_t *res = g_new(parser_t, 1);
+ res->fn = parse_length_value;
+ lv_t *env = g_new(lv_t, 1);
+ env->length = length;
+ env->value = value;
+ res->env = (void*)env;
+ return res;
+}
+
const parser_t* and(const parser_t* p) { return &unimplemented; }
static parse_result_t* parse_not(void* env, parse_state_t* state) {
@@ -881,7 +965,7 @@ static void test_range(void) {
static void test_int64(void) {
const parser_t *int64_ = int64();
- g_check_parse_ok(int64_, "\xff\xff\xff\xfe\x00\x00\x00\x00", 8, "s-0x200000000");
+ g_check_parse_ok(int64_, "\xff\xff\xff\xfe\x00\x00\x00\x00", 8, "s0x200000000");
g_check_parse_failed(int64_, "\xff\xff\xff\xfe\x00\x00\x00", 7);
}
@@ -962,15 +1046,52 @@ static void test_whitespace(void) {
g_check_parse_failed(whitespace_, "_a", 2);
}
-parse_result_t* upcase(parse_result_t *p) {
- return NULL; // shut compiler up
+#include <ctype.h>
+
+const parsed_token_t* upcase(parse_result_t *p) {
+ switch(p->ast->token_type) {
+ case TT_SEQUENCE:
+ {
+ parsed_token_t *ret = a_new_(p->arena, parsed_token_t, 1);
+ counted_array_t *seq = carray_new_sized(p->arena, p->ast->seq->used);
+ ret->token_type = TT_SEQUENCE;
+ for (size_t i=0; i<p->ast->seq->used; ++i) {
+ if (TT_UINT == ((parsed_token_t*)p->ast->seq->elements[i])->token_type) {
+ parsed_token_t *tmp = a_new_(p->arena, parsed_token_t, 1);
+ tmp->token_type = TT_UINT;
+ tmp->uint = toupper(((parsed_token_t*)p->ast->seq->elements[i])->uint);
+ carray_append(seq, tmp);
+ } else {
+ carray_append(seq, p->ast->seq->elements[i]);
+ }
+ }
+ ret->seq = seq;
+ return (const parsed_token_t*)ret;
+ }
+ case TT_UINT:
+ {
+ parsed_token_t *ret = a_new_(p->arena, parsed_token_t, 1);
+ ret->token_type = TT_UINT;
+ ret->uint = toupper(p->ast->uint);
+ return (const parsed_token_t*)ret;
+ }
+ default:
+ return p->ast;
+ }
}
static void test_action(void) {
- const parser_t *action_ = action(sequence(choice(ch('a'), ch('A'), NULL), choice(ch('b'), ch('B'), NULL), NULL), upcase);
-
- g_check_parse_ok(action_, "ab", 2, "(u0x41, u0x42)");
- g_check_parse_ok(action_, "AB", 2, "(u0x41, u0x42)");
+ const parser_t *action_ = action(sequence(choice(ch('a'),
+ ch('A'),
+ NULL),
+ choice(ch('b'),
+ ch('B'),
+ NULL),
+ NULL),
+ upcase);
+
+ g_check_parse_ok(action_, "ab", 2, "(u0x41 u0x42)");
+ g_check_parse_ok(action_, "AB", 2, "(u0x41 u0x42)");
}
static void test_not_in(void) {
diff --git a/src/hammer.h b/src/hammer.h
index 18388b61ab7942df18211d9cda3199c129c14771..a0b93e569bb85a394e248fba9bcf3a939afe9607 100644
--- a/src/hammer.h
+++ b/src/hammer.h
@@ -36,6 +36,7 @@ typedef enum token_type {
TT_SINT,
TT_UINT,
TT_SEQUENCE,
+ TT_USER = 64,
TT_ERR,
TT_MAX
} token_type_t;
@@ -59,173 +60,362 @@ typedef struct parsed_token {
double dbl;
float flt;
counted_array_t *seq; // a sequence of parsed_token_t's
+ void *user;
};
size_t index;
char bit_offset;
} parsed_token_t;
-
-
-/* If a parse fails, the parse result will be NULL.
- * If a parse is successful but there's nothing there (i.e., if end_p succeeds) then there's a parse result but its ast is NULL.
+/**
+ * The result of a successful parse.
+ * If a parse fails, the parse result will be NULL.
+ * If a parse is successful but there's nothing there (i.e., if end_p
+ * succeeds) then there's a parse result but its ast is NULL.
*/
typedef struct parse_result {
const parsed_token_t *ast;
arena_t arena;
} parse_result_t;
-/* Type of an action to apply to an AST, used in the action() parser. */
-typedef parse_result_t* (*action_t)(parse_result_t *p);
+/**
+ * Type of an action to apply to an AST, used in the action() parser.
+ * It can be any (user-defined) function that takes a parse_result_t*
+ * and returns a parsed_token_t*. (This is so that the user doesn't
+ * have to worry about memory allocation; action() does that for you.)
+ * Note that the tagged union in parsed_token_t* supports user-defined
+ * types, so you can create your own token types (corresponding to,
+ * say, structs) and stuff values for them into the void* in the
+ * tagged union in parsed_token_t.
+ */
+typedef const parsed_token_t* (*action_t)(parse_result_t *p);
-/* Type of a boolean attribute-checking function, used in the attr_bool() parser. */
-typedef int (*attr_bool_t)(void *env);
+/**
+ * Type of a boolean attribute-checking function, used in the
+ * attr_bool() parser. It can be any (user-defined) function that takes
+ * a parse_result_t* and returns true or false.
+ */
+typedef bool (*predicate_t)(parse_result_t *p);
typedef struct parser {
parse_result_t* (*fn)(void *env, parse_state_t *state);
void *env;
} parser_t;
+/**
+ * Top-level function to call a parser that has been built over some
+ * piece of input (of known size).
+ */
parse_result_t* parse(const parser_t* parser, const uint8_t* input, size_t length);
-/* Given a string, returns a parser that parses that string value. */
+/**
+ * Given a string, returns a parser that parses that string value.
+ *
+ * Result token type: TT_BYTES
+ */
const parser_t* token(const uint8_t *str, const size_t len);
-/* Given a single character, returns a parser that parses that character. */
+/**
+ * Given a single character, returns a parser that parses that
+ * character.
+ *
+ * Result token type: TT_UINT
+ */
const parser_t* ch(const uint8_t c);
-/* Given two single-character bounds, lower and upper, returns a parser that parses a single character within the range [lower, upper] (inclusive). */
+/**
+ * Given two single-character bounds, lower and upper, returns a parser
+ * that parses a single character within the range [lower, upper]
+ * (inclusive).
+ *
+ * Result token type: TT_UINT
+ */
const parser_t* range(const uint8_t lower, const uint8_t upper);
-/* Returns a parser that parses the specified number of bits. sign == true if signed, false if unsigned. */
+/**
+ * Returns a parser that parses the specified number of bits. sign ==
+ * true if signed, false if unsigned.
+ *
+ * Result token type: TT_SINT if sign == true, TT_UINT if sign == false
+ */
const parser_t* bits(size_t len, bool sign);
-/* Returns a parser that parses a signed 8-byte integer value. */
+/**
+ * Returns a parser that parses a signed 8-byte integer value.
+ *
+ * Result token type: TT_SINT
+ */
const parser_t* int64();
-/* Returns a parser that parses a signed 4-byte integer value. */
+/**
+ * Returns a parser that parses a signed 4-byte integer value.
+ *
+ * Result token type: TT_SINT
+ */
const parser_t* int32();
-/* Returns a parser that parses a signed 2-byte integer value. */
+/**
+ * Returns a parser that parses a signed 2-byte integer value.
+ *
+ * Result token type: TT_SINT
+ */
const parser_t* int16();
-/* Returns a parser that parses a signed 1-byte integer value. */
+/**
+ * Returns a parser that parses a signed 1-byte integer value.
+ *
+ * Result token type: TT_SINT
+ */
const parser_t* int8();
-/* Returns a parser that parses an unsigned 8-byte integer value. */
+/**
+ * Returns a parser that parses an unsigned 8-byte integer value.
+ *
+ * Result token type: TT_UINT
+ */
const parser_t* uint64();
-/* Returns a parser that parses an unsigned 4-byte integer value. */
+/**
+ * Returns a parser that parses an unsigned 4-byte integer value.
+ *
+ * Result token type: TT_UINT
+ */
const parser_t* uint32();
-/* Returns a parser that parses an unsigned 2-byte integer value. */
+/**
+ * Returns a parser that parses an unsigned 2-byte integer value.
+ *
+ * Result token type: TT_UINT
+ */
const parser_t* uint16();
-/* Returns a parser that parses an unsigned 1-byte integer value. */
+/**
+ * Returns a parser that parses an unsigned 1-byte integer value.
+ *
+ * Result token type: TT_UINT
+ */
const parser_t* uint8();
-/* Given another parser, p, returns a parser that skips any whitespace and then applies p. */
+/**
+ * Given another parser, p, returns a parser that skips any whitespace
+ * and then applies p.
+ *
+ * Result token type: p's result type
+ */
const parser_t* whitespace(const parser_t* p);
-/* Given another parser, p, and a function f, returns a parser that applies p, then applies f to everything in the AST of p's result. */
+/**
+ * Given another parser, p, and a function f, returns a parser that
+ * applies p, then applies f to everything in the AST of p's result.
+ *
+ * Result token type: any
+ */
const parser_t* action(const parser_t* p, const action_t a);
-/* Parse a single character *NOT* in charset */
+/**
+ * Parse a single character *NOT* in the given charset.
+ *
+ * Result token type: TT_UINT
+ */
const parser_t* not_in(const uint8_t *charset, int length);
-/* A no-argument parser that succeeds if there is no more input to parse. */
+/**
+ * A no-argument parser that succeeds if there is no more input to
+ * parse.
+ *
+ * Result token type: None. The parse_result_t exists but its AST is NULL.
+ */
const parser_t* end_p();
-/* This parser always fails. */
+/**
+ * This parser always fails.
+ *
+ * Result token type: NULL. Always.
+ */
const parser_t* nothing_p();
-/* Given an null-terminated list of parsers, apply each parser in order. The parse succeeds only if all parsers succeed. */
+/**
+ * Given a null-terminated list of parsers, apply each parser in order.
+ * The parse succeeds only if all parsers succeed.
+ *
+ * Result token type: TT_SEQUENCE
+ */
const parser_t* sequence(const parser_t* p, ...) __attribute__((sentinel));
-/* Given an array of parsers, p_array, apply each parser in order. The first parser to succeed is the result; if no parsers succeed, the parse fails. */
+/**
+ * Given an array of parsers, p_array, apply each parser in order. The
+ * first parser to succeed is the result; if no parsers succeed, the
+ * parse fails.
+ *
+ * Result token type: The type of the first successful parser's result.
+ */
const parser_t* choice(const parser_t* p, ...) __attribute__((sentinel));
-/* Given two parsers, p1 and p2, this parser succeeds in the following cases:
+/**
+ * Given two parsers, p1 and p2, this parser succeeds in the following
+ * cases:
* - if p1 succeeds and p2 fails
* - if both succeed but p1's result is as long as or shorter than p2's
+ *
+ * Result token type: p1's result type.
*/
const parser_t* butnot(const parser_t* p1, const parser_t* p2);
-/* Given two parsers, p1 and p2, this parser succeeds in the following cases:
+/**
+ * Given two parsers, p1 and p2, this parser succeeds in the following
+ * cases:
* - if p1 succeeds and p2 fails
* - if both succeed but p2's result is shorter than p1's
+ *
+ * Result token type: p1's result type.
*/
const parser_t* difference(const parser_t* p1, const parser_t* p2);
-/* Given two parsers, p1 and p2, this parser succeeds if *either* p1 or p2 succeed, but not if they both do.
+/**
+ * Given two parsers, p1 and p2, this parser succeeds if *either* p1 or
+ * p2 succeed, but not if they both do.
+ *
+ * Result token type: The type of the result of whichever parser succeeded.
*/
const parser_t* xor(const parser_t* p1, const parser_t* p2);
-/* Given a parser, p, this parser succeeds for zero or more repetitions of p. */
+/**
+ * Given a parser, p, this parser succeeds for zero or more repetitions
+ * of p.
+ *
+ * Result token type: TT_SEQUENCE
+ */
const parser_t* many(const parser_t* p);
-/* Given a parser, p, this parser succeeds for one or more repetitions of p. */
+/**
+ * Given a parser, p, this parser succeeds for one or more repetitions
+ * of p.
+ *
+ * Result token type: TT_SEQUENCE
+ */
const parser_t* many1(const parser_t* p);
-/* Given a parser, p, this parser succeeds for exactly N repetitions of p. */
+/**
+ * Given a parser, p, this parser succeeds for exactly N repetitions
+ * of p.
+ *
+ * Result token type: TT_SEQUENCE
+ */
const parser_t* repeat_n(const parser_t* p, const size_t n);
-/* Given a parser, p, this parser succeeds with the value p parsed or with an empty result. */
+/**
+ * Given a parser, p, this parser succeeds with the value p parsed or
+ * with an empty result.
+ *
+ * Result token type: If p succeeded, the type of its result; if not, TT_NONE.
+ */
const parser_t* optional(const parser_t* p);
-/* Given a parser, p, this parser succeeds if p succeeds, but doesn't include p's result in the result. */
+/**
+ * Given a parser, p, this parser succeeds if p succeeds, but doesn't
+ * include p's result in the result.
+ *
+ * Result token type: None. The parse_result_t exists but its AST is NULL.
+ */
const parser_t* ignore(const parser_t* p);
-/* Given a parser, p, and a parser for a separator, sep, this parser matches a (possibly empty) list of things that p can parse, separated by sep.
- * For example, if p is repeat1(range('0','9')) and sep is ch(','), sepBy(p, sep) will match a comma-separated list of integers.
+/**
+ * Given a parser, p, and a parser for a separator, sep, this parser
+ * matches a (possibly empty) list of things that p can parse,
+ * separated by sep.
+ * For example, if p is repeat1(range('0','9')) and sep is ch(','),
+ * sepBy(p, sep) will match a comma-separated list of integers.
+ *
+ * Result token type: TT_SEQUENCE
*/
const parser_t* sepBy(const parser_t* p, const parser_t* sep);
-/* Given a parser, p, and a parser for a separator, sep, this parser matches a list of things that p can parse, separated by sep. Unlike sepBy, this ensures that the result has at least one element.
+/**
+ * Given a parser, p, and a parser for a separator, sep, this parser matches a list of things that p can parse, separated by sep. Unlike sepBy, this ensures that the result has at least one element.
* For example, if p is repeat1(range('0','9')) and sep is ch(','), sepBy1(p, sep) will match a comma-separated list of integers.
+ *
+ * Result token type: TT_SEQUENCE
*/
const parser_t* sepBy1(const parser_t* p, const parser_t* sep);
-/* This parser always returns a zero length match, i.e., empty string. */
+/**
+ * This parser always returns a zero length match, i.e., empty string.
+ *
+ * Result token type: None. The parse_result_t exists but its AST is NULL.
+ */
const parser_t* epsilon_p();
-/* This parser attaches an attribute function, which returns true or false, to a parser. The function is evaluated over the parser's result AST.
+/**
+ * This parser applies its first argument to read an unsigned integer
+ * value, then applies its second argument that many times. length
+ * should parse an unsigned integer value; this is checked at runtime.
+ * Specifically, the token_type of the returned token must be TT_UINT.
+ * In future we might relax this to include TT_USER but don't count on it.
+ *
+ * Result token type: TT_SEQUENCE
+ */
+const parser_t* length_value(const parser_t* length, const parser_t* value);
+
+/**
+ * This parser attaches a predicate function, which returns true or
+ * false, to a parser. The function is evaluated over the parser's
+ * result.
* The parse only succeeds if the attribute function returns true.
+ *
+ * Result token type: p's result type if pred succeeded, NULL otherwise.
*/
-const parser_t* attr_bool(const parser_t* p, const attr_bool_t a);
+const parser_t* attr_bool(const parser_t* p, predicate_t pred);
-/* The 'and' parser is a predicate. It asserts that a conditional syntax is satisfied, but consumes no input.
+/**
+ * The 'and' parser asserts that a conditional syntax is satisfied,
+ * but doesn't consume that conditional syntax.
* This is useful for lookahead. As an example:
*
- * Suppose you already have a parser, hex_p, that parses numbers in hexadecimal format (including the leading '0x'). Then
+ * Suppose you already have a parser, hex_p, that parses numbers in
+ * hexadecimal format (including the leading '0x'). Then
* sequence(and(token((const uint8_t*)"0x", 2)), hex_p)
- * checks to see whether there is a leading "0x", *does not* consume the "0x", and then applies hex_p to parse the hex-formatted number.
+ * checks to see whether there is a leading "0x", *does not* consume
+ * the "0x", and then applies hex_p to parse the hex-formatted number.
+ *
+ * 'and' succeeds if p succeeds, and fails if p fails.
*
- * 'and' succeeds if p succeeds, and fails if p fails. Like 'ignore', 'and' does not attach a result to the AST.
+ * Result token type: None. The parse_result_t exists but its AST is NULL.
*/
const parser_t* and(const parser_t* p);
-/* The 'not' parser is a predicate. It asserts that a conditional syntax is *not* satisfied, and consumes no input.
+/**
+ * The 'not' parser asserts that a conditional syntax is *not*
+ * satisfied, but doesn't consume that conditional syntax.
* As a somewhat contrived example:
*
* Since 'choice' applies its arguments in order, the following parser:
* sequence(ch('a'), choice(ch('+'), token((const uint8_t*)"++"), NULL), ch('b'), NULL)
- * will not parse "a++b", because once choice() has succeeded, it will not backtrack and try other alternatives if a later parser in the sequence
- * fails.
- * Instead, you can force the use of the second alternative by turning the ch('+') alternative into a sequence with not:
+ * will not parse "a++b", because once choice() has succeeded, it will
+ * not backtrack and try other alternatives if a later parser in the
+ * sequence fails.
+ * Instead, you can force the use of the second alternative by turning
+ * the ch('+') alternative into a sequence with not:
* sequence(ch('a'), choice(sequence(ch('+'), not(ch('+')), NULL), token((const uint8_t*)"++")), ch('b'), NULL)
- * If the input string is "a+b", the first alternative is applied; if the input string is "a++b", the second alternative is applied.
+ * If the input string is "a+b", the first alternative is applied; if
+ * the input string is "a++b", the second alternative is applied.
+ *
+ * Result token type: None. The parse_result_t exists but its AST is NULL.
*/
const parser_t* not(const parser_t* p);
/**
- * Create a parser that just calls out to another, as yet unknown, parser.
+ * Create a parser that just calls out to another, as yet unknown,
+ * parser.
* Note that the inner parser gets bound later, with bind_indirect.
* This can be used to create recursive parsers.
+ *
+ * Result token type: the type of whatever parser is bound to it with
+ * bind_indirect().
*/
parser_t *indirect();
/**
- * Set the inner parser of an indirect. See comments on indirect for details.
+ * Set the inner parser of an indirect. See comments on indirect for
+ * details.
*/
void bind_indirect(parser_t* indirect, parser_t* inner);
diff --git a/src/internal.h b/src/internal.h
index 4cd5bf6dcf9c323daddefd6d2778805243962096..09970e01a01f45665924b412e3ae8aab379f4009 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -26,7 +26,7 @@
#else
#define assert_message(check, message) do { \
if (!(check)) \
- errx(1, "Assertation failed (programmer error): %s", message); \
+ errx(1, "Assertion failed (programmer error): %s", message); \
} while(0)
#endif
#define false 0
diff --git a/src/pprint.c b/src/pprint.c
index 250ecfbef104842374aaf98308984183d50240ef..ac0d02db611f7fbe1c91d5ca4d3397fc3d738558 100644
--- a/src/pprint.c
+++ b/src/pprint.c
@@ -94,6 +94,10 @@ static inline void append_buf_c(struct result_buf *buf, char v) {
static void unamb_sub(const parsed_token_t* tok, struct result_buf *buf) {
char* tmpbuf;
int len;
+ if (!tok) {
+ append_buf(buf, "NULL", 4);
+ return;
+ }
switch (tok->token_type) {
case TT_NONE:
append_buf(buf, "null", 4);