Free DFA at end of integration tests

.build.yml

@@ -0,0 +1,18 @@
+image: alpine/edge
+packages:
+  - clang
+  - cmake
+  - compiler-rt
+  - ninja
+sources:
+  - https://git.sr.ht/~cdo/regex-engine
+tasks:
+  - configure: |
+      cd regex-engine
+      cmake -GNinja -Bbuild -DSANITIZERS=on -DCMAKE_BUILD_TYPE=Debug -DCMAKE_C_COMPILER=clang
+  - build: |
+      cd regex-engine
+      scripts/build.sh
+  - test: |
+      cd regex-engine
+      scripts/test.sh

CMakeLists.txt

@@ -8,7 +8,6 @@ enable_testing()
 
 function(set_default_target_options target)
   set_property(TARGET ${target} PROPERTY C_STANDARD 11)
-  set_property(TARGET ${target} PROPERTY C_EXTENSIONS OFF)
   target_compile_options(${target} PRIVATE -Wall -Wextra -pedantic)
   if(${SANITIZERS})
 	target_compile_options(${target} PRIVATE -fsanitize=address,undefined)
@@ -19,4 +18,3 @@ endfunction()
 add_subdirectory(lib)
 add_subdirectory(tests)
 add_subdirectory(demo)
-add_subdirectory(benchmarks)

README

@@ -7,8 +7,8 @@ so here we are.
 
                                Grammar
 
-The engine does not support any specific standard's syntax, unless by
+This engine is not going to be strictly supporting any standard
-coincidence.  The grammar I've implemented for expressions is:
+syntax; the expression syntax I intend to support follows.
 
 	regex ::= sequence ( '|' sequence )*
 	sequence ::= term+
@@ -23,7 +23,7 @@ coincidence.  The grammar I've implemented for expressions is:
 
 The build uses CMake.  There are two scripts, build.sh and test.sh,
 which will (much to everybody's shock) build the project and run the
-tests.  I use Clang but the code is ISO C11 so it should compile just
+tests.  I use Clang but the code is ISO C11, it should compile just
 fine with GCC.  You might need to faff with CMakeLists.txt to get it
 to work with another compiler due to command-line flag nonsense.
 

benchmarks/CMakeLists.txt

@@ -1,20 +0,0 @@
-add_library(benchmarking benchmarking.c)
-set_default_target_options(benchmarking)
-target_include_directories(benchmarking PUBLIC include)
-
-function(add_benchmark_suite source)
-  string(REGEX REPLACE ".c$" "" name ${source})
-  add_executable(${name} ${source})
-  set_default_target_options(${name})
-  target_link_libraries(${name} PRIVATE lib benchmarking m)
-endfunction()
-
-function(add_benchmark_suites)
-  foreach(source ${ARGN})
-	add_benchmark_suite(${source})
-  endforeach()
-endfunction()
-
-add_benchmark_suites(
-  matching_benchmarks.c
-)

benchmarks/benchmarking.c

@@ -1,85 +0,0 @@
-/*
- * Copyright (c) Camden Dixie O'Brien
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-#include "benchmarking.h"
-
-#include <assert.h>
-#include <math.h>
-#include <stdio.h>
-
-#define SWAP(x, y) \
-	do { \
-		const double tmp = x; \
-		x = y; \
-		y = tmp; \
-	} while (0)
-
-clock_t benchmark_start, benchmark_end;
-
-static void sort(double *xs, int n)
-{
-	if (n <= 0)
-		return;
-
-	const double pivot = xs[(n - 1) / 2];
-	int lt = 0;
-	int eq = 0;
-	int gt = n - 1;
-	while (eq <= gt) {
-		if (xs[eq] < pivot) {
-			SWAP(xs[eq], xs[lt]);
-			++lt;
-			++eq;
-		} else if (xs[eq] > pivot) {
-			SWAP(xs[eq], xs[gt]);
-			--gt;
-		} else {
-			++eq;
-		}
-	}
-
-	sort(xs, lt);
-	sort(xs + gt + 1, n - (gt + 1));
-}
-
-void benchmark_summarise(double *res, int reps, benchmark_summary_t *out)
-{
-	assert(reps > 0);
-
-	sort(res, reps);
-	const double median = res[reps / 2];
-
-	double sum = 0;
-	for (int i = 0; i < reps; ++i)
-		sum += res[i];
-	const double mean = sum / reps;
-
-	double diff_sum = 0;
-	for (int i = 0; i < reps; ++i)
-		diff_sum += pow(res[i] - mean, 2);
-	const double variance = diff_sum / (reps - 1);
-
-	out->reps = reps;
-	out->total = sum;
-	out->median = median;
-	out->mean = mean;
-	out->min = res[0];
-	out->max = res[reps - 1];
-	out->stddev = sqrt(variance);
-}
-
-void benchmark_print_header(void)
-{
-	printf(
-	    "%-12s %13s %13s %13s %13s %12s\n", "benchmark", "median (µs)",
-	    "mean (µs)", "min (µs)", "max (µs)", "stddev");
-}
-
-void benchmark_print(const char *name, const benchmark_summary_t *s)
-{
-	printf(
-	    "%-12s %12.2f %12.2f %12.2f %12.2f %12.2f\n", name, s->median,
-	    s->mean, s->min, s->max, s->stddev);
-}

benchmarks/include/benchmarking.h

@@ -1,50 +0,0 @@
-/*
- * Copyright (c) Camden Dixie O'Brien
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-#ifndef BENCHMARKING_H
-#define BENCHMARKING_H
-
-#include <time.h>
-
-typedef struct {
-	int reps;
-	double total, median, mean, min, max, stddev;
-} benchmark_summary_t;
-
-#define CLOCK_MICROS(c) (1000000 * (double)c / CLOCKS_PER_SEC)
-
-#define BENCHMARKING_BEGIN() benchmark_print_header()
-#define BENCHMARKING_END() 0
-
-#define START_CLOCK() \
-	do { \
-		benchmark_start = clock(); \
-	} while (0)
-
-#define STOP_CLOCK() \
-	do { \
-		benchmark_end = clock(); \
-	} while (0)
-
-#define RUN_BENCHMARK(reps, name, fn, ...) \
-	do { \
-		double res[reps]; \
-		for (int i = 0; i < reps; ++i) { \
-			fn(__VA_ARGS__); \
-			res[i] = CLOCK_MICROS(benchmark_end) \
-			    - CLOCK_MICROS(benchmark_start); \
-		} \
-		benchmark_summary_t summary; \
-		benchmark_summarise(res, reps, &summary); \
-		benchmark_print(name, &summary); \
-	} while (0)
-
-extern clock_t benchmark_start, benchmark_end;
-
-void benchmark_summarise(double *res, int reps, benchmark_summary_t *out);
-void benchmark_print_header(void);
-void benchmark_print(const char *name, const benchmark_summary_t *summary);
-
-#endif

benchmarks/matching_benchmarks.c

@@ -1,54 +0,0 @@
-/*
- * Copyright (c) Camden Dixie O'Brien
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-#include "benchmarking.h"
-#include "compile.h"
-
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/time.h>
-
-#define LEN 1000
-#define RANGE_FIRST 'a'
-#define RANGE_LAST 'z'
-
-#define CLAMP_CHAR(x) (RANGE_FIRST + x % (RANGE_LAST - RANGE_FIRST + 1))
-
-#define RUN_MATCHING_BENCHMARK(reps, name, regex) \
-	do { \
-		fsa_t fsa; \
-		compile(regex, strlen(regex), &fsa); \
-		RUN_BENCHMARK(reps, name, matching_benchmark, &fsa); \
-		fsa_free(&fsa); \
-	} while (0)
-
-static void matching_benchmark(const fsa_t *fsa)
-{
-	char s[LEN];
-	for (int j = 0; j < LEN; ++j)
-		s[j] = CLAMP_CHAR(rand());
-
-	volatile bool match;
-	START_CLOCK();
-	match = fsa_accepts(fsa, s, LEN);
-	STOP_CLOCK();
-	(void)match;
-}
-
-int main(void)
-{
-	struct timeval tv;
-	gettimeofday(&tv, NULL);
-	srand(tv.tv_usec);
-
-	BENCHMARKING_BEGIN();
-
-	RUN_MATCHING_BENCHMARK(10000, "foo or bar", ".*(foo|bar).*");
-	RUN_MATCHING_BENCHMARK(10000, "regex #1", ".*(abc!?)*|dd+.*");
-	RUN_MATCHING_BENCHMARK(10000, "regex #2", ".*(l|wh)?[aeiou]+.*");
-
-	return BENCHMARKING_END();
-}

demo/shitgrep.c

@@ -12,11 +12,6 @@
 
 #define BUFFER_START_CAPACITY 128
 
-#define PREFIX ".*("
-#define PREFIX_LEN 3
-#define SUFFIX ").*"
-#define SUFFIX_LEN 3
-
 int main(int argc, char *argv[])
 {
 	if (argc != 2) {
@@ -24,15 +19,8 @@ int main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
-	const int input_len = strlen(argv[1]);
-	const int regex_len = input_len + 6;
-	char *regex = malloc(regex_len);
-	memcpy(regex, PREFIX, PREFIX_LEN);
-	memcpy(regex + PREFIX_LEN, argv[1], input_len);
-	memcpy(regex + PREFIX_LEN + input_len, SUFFIX, SUFFIX_LEN);
-
 	fsa_t dfa;
-	if (!compile(regex, regex_len, &dfa)) {
+	if (!compile(argv[1], strlen(argv[1]), &dfa)) {
 		fprintf(stderr, "Failed to parse regex\n");
 		return EXIT_FAILURE;
 	}

lib/CMakeLists.txt

@@ -2,9 +2,11 @@ add_library(lib
   compile.c
   construct.c
   convert.c
+  desugar.c
   fsa.c
   min_heap.c
   parse.c
+  regex.c
 )
 set_default_target_options(lib)
 target_include_directories(lib PUBLIC include)

lib/compile.c

@@ -5,19 +5,21 @@
 
 #include "compile.h"
 
+#include "parse.h"
+#include "desugar.h"
 #include "construct.h"
 #include "convert.h"
-#include "parse.h"
 
 bool compile(const char *regex, int len, fsa_t *dfa_out)
 {
-	parse_tree_t pt;
+	regex_t pt;
 	if (-1 == parse_expr(regex, len, &pt))
 		return false;
+	desugar_regex(&pt);
 
 	fsa_t nfa;
 	construct_nfa(&pt, &nfa);
-	parse_tree_free(&pt);
+	regex_free(&pt);
 
 	convert_to_dfa(&nfa, dfa_out);
 	fsa_free(&nfa);

lib/construct.c

@@ -25,9 +25,6 @@ static void add_fsa(fsa_t *f, const fsa_t *o, int *init_out, int *final_out)
 	}
 	memcpy(f->states + f->count, o->states, o->count * sizeof(fsa_state_t));
 
-	// Mark o's final state as non-final.
-	f->states[f->count].final = false;
-
 	// Retarget the rules of the copied states to refer to the new
 	// state indices.
 	for (int i = f->count; i < count; ++i) {
@@ -115,119 +112,62 @@ static void prepend_fsa(fsa_t *f, const fsa_t *o)
 	f->count = count;
 }
 
-static void construct_base(fsa_t *out)
+static void construct_base(fsa_t *out, int symbol)
 {
 	fsa_init(out);
+	const int id = fsa_add_state(out);
+	fsa_add_rule(out, id, out->initial, symbol);
+	out->initial = id;
 	out->states[0].final = true;
-	out->initial = fsa_add_state(out);
-}
-
-static void construct_symbol(fsa_t *out, int symbol)
-{
-	construct_base(out);
-	fsa_add_rule(out, out->initial, 0, symbol);
-}
-
-static bool in_class(const parse_class_t *class, char c)
-{
-	for (int i = 0; i < class->count; ++i) {
-		if (class->contents[i] == c)
-			return true;
-	}
-	return false;
-}
-
-static void construct_class(fsa_t *out, const parse_class_t *class)
-{
-	construct_base(out);
-	if (class->negated) {
-		for (int i = 0; i < CHAR_COUNT; ++i) {
-			if (!in_class(class, i))
-				fsa_add_rule(out, out->initial, 0, i);
-		}
-	} else {
-		for (int i = 0; i < class->count; ++i)
-			fsa_add_rule(out, out->initial, 0, class->contents[i]);
-	}
-}
-
-static void construct_wildcard(fsa_t *out)
-{
-	construct_base(out);
-	for (int i = 0; i < CHAR_COUNT; ++i)
-		fsa_add_rule(out, out->initial, 0, i);
-}
-
-static void base_quantify(fsa_t *out, int *init_out, int *final_out)
-{
-	fsa_t f;
-	memcpy(&f, out, sizeof(fsa_t));
-	construct_base(out);
-	add_fsa(out, &f, init_out, final_out);
-	fsa_add_rule(out, out->initial, *init_out, EPSILON);
-	fsa_add_rule(out, *final_out, 0, EPSILON);
 }
 
 static void construct_star(fsa_t *out)
 {
-	int sub_init, sub_final;
+	fsa_t f;
-	base_quantify(out, &sub_init, &sub_final);
+	memcpy(&f, out, sizeof(fsa_t));
-	fsa_add_rule(out, sub_final, sub_init, EPSILON);
+
-	fsa_add_rule(out, out->initial, 0, EPSILON);
+	construct_base(out, EPSILON);
+	int f_initial, f_final;
+	add_fsa(out, &f, &f_initial, &f_final);
+	fsa_add_rule(out, out->initial, f_initial, EPSILON);
+	fsa_add_rule(out, f_final, f_initial, EPSILON);
+	fsa_add_rule(out, f_final, 0, EPSILON);
 }
 
-static void construct_plus(fsa_t *out)
+static void construct_term(const regex_term_t *term, fsa_t *out)
-{
-	int sub_init, sub_final;
-	base_quantify(out, &sub_init, &sub_final);
-	fsa_add_rule(out, sub_final, sub_init, EPSILON);
-}
-
-static void construct_qmark(fsa_t *out)
-{
-	int sub_init, sub_final;
-	base_quantify(out, &sub_init, &sub_final);
-	fsa_add_rule(out, out->initial, 0, EPSILON);
-}
-
-static void construct_term(const parse_term_t *term, fsa_t *out)
 {
 	switch (term->type) {
-	case PARSE_TERM_EMPTY:
+	case REGEX_TERM_EMPTY:
-		construct_symbol(out, EPSILON);
+		construct_base(out, EPSILON);
 		break;
-	case PARSE_TERM_LITERAL:
+	case REGEX_TERM_LITERAL:
-		construct_symbol(out, term->literal);
+		construct_base(out, term->literal);
 		break;
-	case PARSE_TERM_SUBEXPR:
+	case REGEX_TERM_SUBEXPR:
 		construct_nfa(&term->subexpr, out);
 		break;
-	case PARSE_TERM_CLASS:
+	case REGEX_TERM_WILDCARD:
-		construct_class(out, &term->class);
+	case REGEX_TERM_CLASS:
-		break;
+		assert(false);
-	case PARSE_TERM_WILDCARD:
-		construct_wildcard(out);
 		break;
 	}
 
 	switch (term->quantifier) {
-	case PARSE_QUANTIFIER_NONE:
+	case REGEX_QUANTIFIER_NONE:
 		break;
-	case PARSE_QUANTIFIER_STAR:
+	case REGEX_QUANTIFIER_STAR:
 		construct_star(out);
 		break;
-	case PARSE_QUANTIFIER_PLUS:
+	case REGEX_QUANTIFIER_PLUS:
-		construct_plus(out);
+	case REGEX_QUANTIFIER_QMARK:
-		break;
+		assert(false);
-	case PARSE_QUANTIFIER_QMARK:
-		construct_qmark(out);
 		break;
 	}
 
 	assert(out->states[0].final);
 }
 
-static void construct_sequence(const parse_sequence_t *seq, fsa_t *out)
+static void construct_sequence(const regex_sequence_t *seq, fsa_t *out)
 {
 	assert(seq->count > 0);
 
@@ -261,7 +201,7 @@ static void construct_union(fsa_t *f, const fsa_t *o)
 	fsa_add_rule(f, final, 0, EPSILON);
 }
 
-void construct_nfa(const parse_tree_t *regex, fsa_t *out)
+void construct_nfa(const regex_t *regex, fsa_t *out)
 {
 	assert(regex->count > 0);
 

lib/convert.c

@@ -160,17 +160,13 @@ static void insert(table_t *table, int *nfa_states, int count, int dfa_state)
 	table->entries = calloc(table->capacity, sizeof(table_entry_t));
 	assert(NULL != table->entries);
 	for (int i = 0; i < old_capacity; ++i) {
-		if (0 != entries[i].nfa_state_count) {
+		if (0 != entries[i].nfa_state_count)
-			insert(
+			continue;
-			    table, entries[i].nfa_states, entries[i].nfa_state_count,
+		insert(
-			    entries[i].dfa_state);
+		    table, entries[i].nfa_states, entries[i].nfa_state_count,
-		}
+		    entries[i].dfa_state);
 	}
 	free(entries);
-
-	// Recurse to insert the entry now that the table has been
-	// expanded.
-	insert(table, nfa_states, count, dfa_state);
 }
 
 static bool lookup_or_create(

lib/desugar.c

@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) Camden Dixie O'Brien
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+#include "desugar.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+static void desugar_class(regex_term_t *term)
+{
+	assert(!term->class.negated);
+
+	const int count = term->class.count;
+	regex_sequence_t *alternatives
+	    = malloc(count * sizeof(regex_sequence_t));
+	assert(NULL != alternatives);
+
+	for (int i = 0; i < count; ++i) {
+		regex_term_t *terms = malloc(sizeof(regex_term_t));
+		terms[0].quantifier = REGEX_QUANTIFIER_NONE;
+		terms[0].type = REGEX_TERM_LITERAL;
+		terms[0].literal = term->class.contents[i];
+		alternatives[i].count = alternatives[i].capacity = 1;
+		alternatives[i].contents = terms;
+	}
+
+	regex_class_free(&term->class);
+	term->type = REGEX_TERM_SUBEXPR;
+	term->subexpr.count = term->subexpr.capacity = count;
+	term->subexpr.contents = alternatives;
+}
+
+static void deep_copy_term(regex_term_t *dst, regex_term_t *src);
+
+static void deep_copy_sequence(regex_sequence_t *dst, regex_sequence_t *src)
+{
+	dst->count = dst->capacity = src->count;
+	dst->contents = malloc(dst->capacity * sizeof(regex_term_t));
+	assert(NULL != dst->contents);
+
+	for (int i = 0; i < dst->count; ++i)
+		deep_copy_term(&dst->contents[i], &src->contents[i]);
+}
+
+static void deep_copy_term(regex_term_t *dst, regex_term_t *src)
+{
+	assert(REGEX_TERM_WILDCARD != src->type);
+	assert(REGEX_TERM_CLASS != src->type);
+
+	memcpy(dst, src, sizeof(regex_term_t));
+	if (REGEX_TERM_SUBEXPR == src->type) {
+		dst->subexpr.capacity = src->subexpr.count;
+		dst->subexpr.contents
+		    = malloc(dst->subexpr.capacity * sizeof(regex_sequence_t));
+		assert(NULL != dst->subexpr.contents);
+
+		for (int i = 0; i < dst->subexpr.count; ++i) {
+			deep_copy_sequence(
+			    &dst->subexpr.contents[i], &src->subexpr.contents[i]);
+		}
+	}
+}
+
+static void desugar_plus(regex_term_t *term)
+{
+	regex_sequence_t *alternatives = malloc(sizeof(regex_sequence_t));
+	assert(NULL != alternatives);
+
+	alternatives[0].count = alternatives[0].capacity = 2;
+	alternatives[0].contents = malloc(2 * sizeof(regex_term_t));
+	assert(NULL != alternatives[0].contents);
+
+	memcpy(&alternatives[0].contents[0], term, sizeof(regex_term_t));
+	deep_copy_term(&alternatives[0].contents[1], term);
+	alternatives[0].contents[0].quantifier = REGEX_QUANTIFIER_NONE;
+	alternatives[0].contents[1].quantifier = REGEX_QUANTIFIER_STAR;
+
+	term->quantifier = REGEX_QUANTIFIER_NONE;
+	term->type = REGEX_TERM_SUBEXPR;
+	term->subexpr.count = term->subexpr.capacity = 1;
+	term->subexpr.contents = alternatives;
+}
+
+static void desugar_qmark(regex_term_t *term)
+{
+	regex_sequence_t *alternatives = malloc(2 * sizeof(regex_sequence_t));
+	assert(NULL != alternatives);
+
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = malloc(sizeof(regex_term_t));
+	assert(NULL != alternatives[0].contents);
+	alternatives[0].contents[0].quantifier = REGEX_QUANTIFIER_NONE;
+	alternatives[0].contents[0].type = REGEX_TERM_EMPTY;
+
+	alternatives[1].count = alternatives[0].capacity = 1;
+	alternatives[1].contents = malloc(sizeof(regex_term_t));
+	assert(NULL != alternatives[1].contents);
+	memcpy(&alternatives[1].contents[0], term, sizeof(regex_term_t));
+	alternatives[1].contents[0].quantifier = REGEX_QUANTIFIER_NONE;
+
+	term->quantifier = REGEX_QUANTIFIER_NONE;
+	term->type = REGEX_TERM_SUBEXPR;
+	term->subexpr.count = term->subexpr.capacity = 2;
+	term->subexpr.contents = alternatives;
+}
+
+static void desugar_term(regex_term_t *term)
+{
+	switch (term->type) {
+	case REGEX_TERM_WILDCARD:
+		assert(false);
+		break;
+	case REGEX_TERM_CLASS:
+		desugar_class(term);
+		break;
+
+	case REGEX_TERM_SUBEXPR:
+		desugar_regex(&term->subexpr);
+		break;
+
+	case REGEX_TERM_LITERAL:
+	case REGEX_TERM_EMPTY:
+		break;
+	}
+
+	switch (term->quantifier) {
+	case REGEX_QUANTIFIER_PLUS:
+		desugar_plus(term);
+		break;
+	case REGEX_QUANTIFIER_QMARK:
+		desugar_qmark(term);
+		break;
+
+	case REGEX_QUANTIFIER_NONE:
+	case REGEX_QUANTIFIER_STAR:
+		break;
+	}
+}
+
+void desugar_regex(regex_t *regex)
+{
+	for (int i = 0; i < regex->count; ++i) {
+		for (int j = 0; j < regex->contents[i].count; ++j) {
+			desugar_term(&regex->contents[i].contents[j]);
+		}
+	}
+}

lib/fsa.c

@@ -33,8 +33,7 @@ int fsa_add_state(fsa_t *fsa)
 {
 	if (fsa->count >= fsa->capacity) {
 		fsa->capacity *= 2;
-		fsa->states
+		fsa->states = realloc(fsa->states, fsa->capacity);
-		    = realloc(fsa->states, fsa->capacity * sizeof(fsa_state_t));
 		assert(NULL != fsa->states);
 	}
 
@@ -57,8 +56,7 @@ void fsa_add_rule(fsa_t *fsa, int from, int to, int input)
 	fsa_state_t *state = &fsa->states[from];
 	if (state->count >= state->capacity) {
 		state->capacity *= 2;
-		state->rules
+		state->rules = realloc(state->rules, state->capacity);
-		    = realloc(state->rules, state->capacity * sizeof(fsa_rule_t));
 		assert(NULL != state->rules);
 	}
 

lib/include/construct.h

@@ -7,8 +7,8 @@
 #define CONSTRUCT_H
 
 #include "fsa.h"
-#include "parse.h"
+#include "regex.h"
 
-void construct_nfa(const parse_tree_t *regex, fsa_t *out);
+void construct_nfa(const regex_t *regex, fsa_t *out);
 
 #endif

lib/include/desugar.h

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) Camden Dixie O'Brien
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+#ifndef DESUGAR_H
+#define DESUGAR_H
+
+#include "regex.h"
+
+void desugar_regex(regex_t *regex);
+
+#endif

lib/include/parse.h

@@ -6,53 +6,10 @@
 #ifndef PARSE_H
 #define PARSE_H
 
-#include <stdbool.h>
+#include "regex.h"
 
 #define PARSE_FAIL (-1)
 
-typedef struct {
+int parse_expr(const char *input, int rem, regex_t *out);
-	bool negated;
-	int count, capacity;
-	char *contents;
-} parse_class_t;
-
-typedef enum {
-	PARSE_QUANTIFIER_NONE,
-	PARSE_QUANTIFIER_STAR,
-	PARSE_QUANTIFIER_PLUS,
-	PARSE_QUANTIFIER_QMARK,
-} parse_quantifier_t;
-
-typedef enum {
-	PARSE_TERM_WILDCARD,
-	PARSE_TERM_CLASS,
-	PARSE_TERM_LITERAL,
-	PARSE_TERM_SUBEXPR,
-	PARSE_TERM_EMPTY,
-} parse_term_type_t;
-
-struct _parse_term;
-typedef struct {
-	int count, capacity;
-	struct _parse_term *contents;
-} parse_sequence_t;
-
-typedef struct {
-	int count, capacity;
-	parse_sequence_t *contents;
-} parse_tree_t;
-
-typedef struct _parse_term {
-	parse_quantifier_t quantifier;
-	parse_term_type_t type;
-	union {
-		parse_class_t class;
-		char literal;
-		parse_tree_t subexpr;
-	};
-} parse_term_t;
-
-int parse_expr(const char *input, int rem, parse_tree_t *out);
-void parse_tree_free(const parse_tree_t *t);
 
 #endif

lib/include/regex.h

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) Camden Dixie O'Brien
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+#ifndef REGEX_H
+#define REGEX_H
+
+#include <stdbool.h>
+
+typedef struct {
+	bool negated;
+	int count, capacity;
+	char *contents;
+} regex_class_t;
+
+typedef enum {
+	REGEX_QUANTIFIER_NONE,
+	REGEX_QUANTIFIER_STAR,
+	REGEX_QUANTIFIER_PLUS,
+	REGEX_QUANTIFIER_QMARK,
+} regex_quantifier_t;
+
+typedef enum {
+	REGEX_TERM_WILDCARD,
+	REGEX_TERM_CLASS,
+	REGEX_TERM_LITERAL,
+	REGEX_TERM_SUBEXPR,
+	REGEX_TERM_EMPTY,
+} regex_term_type_t;
+
+struct _regex_term;
+typedef struct {
+	int count, capacity;
+	struct _regex_term *contents;
+} regex_sequence_t;
+
+typedef struct {
+	int count, capacity;
+	regex_sequence_t *contents;
+} regex_t;
+
+typedef struct _regex_term {
+	regex_quantifier_t quantifier;
+	regex_term_type_t type;
+	union {
+		regex_class_t class;
+		char literal;
+		regex_t subexpr;
+	};
+} regex_term_t;
+
+void regex_free(const regex_t *t);
+void regex_class_free(const regex_class_t *c);
+
+#endif

lib/parse.c

@@ -45,7 +45,7 @@ static int parse_literal(const char *input, int rem, char *out)
 	}
 }
 
-static int parse_class(const char *input, int rem, parse_class_t *out)
+static int parse_class(const char *input, int rem, regex_class_t *out)
 {
 	int result, used = 0;
 
@@ -87,7 +87,7 @@ static int parse_class(const char *input, int rem, parse_class_t *out)
 	return out->count > 0 ? used : -1;
 }
 
-static int parse_term(const char *input, int rem, parse_term_t *out)
+static int parse_term(const char *input, int rem, regex_term_t *out)
 {
 	int result, used = 0;
 
@@ -95,7 +95,7 @@ static int parse_term(const char *input, int rem, parse_term_t *out)
 		return PARSE_FAIL;
 
 	if ('.' == input[0]) {
-		out->type = PARSE_TERM_WILDCARD;
+		out->type = REGEX_TERM_WILDCARD;
 		++used;
 	} else if ('(' == input[0]) {
 		++used;
@@ -103,7 +103,7 @@ static int parse_term(const char *input, int rem, parse_term_t *out)
 		result = parse_expr(input + used, rem - used, &out->subexpr);
 		if (PARSE_FAIL == result)
 			return PARSE_FAIL;
-		out->type = PARSE_TERM_SUBEXPR;
+		out->type = REGEX_TERM_SUBEXPR;
 		used += result;
 
 		if (')' != input[used])
@@ -113,54 +113,54 @@ static int parse_term(const char *input, int rem, parse_term_t *out)
 		result = parse_class(input + used, rem - used, &out->class);
 		if (PARSE_FAIL == result)
 			return PARSE_FAIL;
-		out->type = PARSE_TERM_CLASS;
+		out->type = REGEX_TERM_CLASS;
 		used += result;
 	} else {
 		result = parse_literal(input + used, rem - used, &out->literal);
 		if (PARSE_FAIL == result)
 			return PARSE_FAIL;
-		out->type = PARSE_TERM_LITERAL;
+		out->type = REGEX_TERM_LITERAL;
 		used += result;
 	}
 
 	if (used < rem) {
 		switch (input[used]) {
 		case '*':
-			out->quantifier = PARSE_QUANTIFIER_STAR;
+			out->quantifier = REGEX_QUANTIFIER_STAR;
 			++used;
 			break;
 		case '+':
-			out->quantifier = PARSE_QUANTIFIER_PLUS;
+			out->quantifier = REGEX_QUANTIFIER_PLUS;
 			++used;
 			break;
 		case '?':
-			out->quantifier = PARSE_QUANTIFIER_QMARK;
+			out->quantifier = REGEX_QUANTIFIER_QMARK;
 			++used;
 			break;
 		default:
-			out->quantifier = PARSE_QUANTIFIER_NONE;
+			out->quantifier = REGEX_QUANTIFIER_NONE;
 		}
 	} else {
-		out->quantifier = PARSE_QUANTIFIER_NONE;
+		out->quantifier = REGEX_QUANTIFIER_NONE;
 	}
 
 	return used;
 }
 
-static int parse_sequence(const char *input, int rem, parse_sequence_t *out)
+static int parse_sequence(const char *input, int rem, regex_sequence_t *out)
 {
 	int result, used = 0;
 
 	out->count = 0;
 	out->capacity = SEQUENCE_START_CAPACITY;
-	out->contents = malloc(out->capacity * sizeof(parse_term_t));
+	out->contents = malloc(out->capacity * sizeof(regex_term_t));
 	assert(NULL != out->contents);
 
 	while (used < rem) {
 		if (out->count >= out->capacity) {
 			out->capacity *= 2;
 			out->contents = realloc(
-			    out->contents, out->capacity * sizeof(parse_term_t));
+			    out->contents, out->capacity * sizeof(regex_term_t));
 			assert(NULL != out->contents);
 		}
 
@@ -175,13 +175,13 @@ static int parse_sequence(const char *input, int rem, parse_sequence_t *out)
 	return out->count > 0 ? used : -1;
 }
 
-int parse_expr(const char *input, int rem, parse_tree_t *out)
+int parse_expr(const char *input, int rem, regex_t *out)
 {
 	int result, used = 0;
 
 	out->count = 0;
 	out->capacity = TREE_START_CAPACITY;
-	out->contents = malloc(out->capacity * sizeof(parse_sequence_t));
+	out->contents = malloc(out->capacity * sizeof(regex_sequence_t));
 	assert(NULL != out->contents);
 
 	result = parse_sequence(input + used, rem - used, &out->contents[0]);
@@ -198,7 +198,7 @@ int parse_expr(const char *input, int rem, parse_tree_t *out)
 		if (out->count >= out->capacity) {
 			out->capacity *= 2;
 			out->contents = realloc(
-			    out->contents, out->capacity * sizeof(parse_sequence_t));
+			    out->contents, out->capacity * sizeof(regex_sequence_t));
 			assert(NULL != out->contents);
 		}
 
@@ -212,37 +212,3 @@ int parse_expr(const char *input, int rem, parse_tree_t *out)
 
 	return used;
 }
-
-static void class_free(const parse_class_t *c)
-{
-	if (NULL != c->contents)
-		free(c->contents);
-}
-
-static void sequence_free(const parse_sequence_t *s)
-{
-	if (NULL != s->contents) {
-		for (int i = 0; i < s->count; ++i) {
-			switch (s->contents[i].type) {
-			case PARSE_TERM_CLASS:
-				class_free(&s->contents[i].class);
-				break;
-			case PARSE_TERM_SUBEXPR:
-				parse_tree_free(&s->contents[i].subexpr);
-				break;
-			default:
-				break;
-			}
-		}
-		free(s->contents);
-	}
-}
-
-void parse_tree_free(const parse_tree_t *t)
-{
-	if (NULL != t->contents) {
-		for (int i = 0; i < t->count; ++i)
-			sequence_free(&t->contents[i]);
-		free(t->contents);
-	}
-}

lib/regex.c

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) Camden Dixie O'Brien
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+#include "regex.h"
+
+#include <stdlib.h>
+
+static void sequence_free(const regex_sequence_t *s)
+{
+	if (NULL != s->contents) {
+		for (int i = 0; i < s->count; ++i) {
+			switch (s->contents[i].type) {
+			case REGEX_TERM_CLASS:
+				regex_class_free(&s->contents[i].class);
+				break;
+			case REGEX_TERM_SUBEXPR:
+				regex_free(&s->contents[i].subexpr);
+				break;
+			default:
+				break;
+			}
+		}
+		free(s->contents);
+	}
+}
+
+void regex_free(const regex_t *t)
+{
+	if (NULL != t->contents) {
+		for (int i = 0; i < t->count; ++i)
+			sequence_free(&t->contents[i]);
+		free(t->contents);
+	}
+}
+
+void regex_class_free(const regex_class_t *c)
+{
+	if (NULL != c->contents)
+		free(c->contents);
+}

scripts/entr.sh

@@ -1,4 +1,4 @@
 #!/bin/sh
 cd "$(git rev-parse --show-toplevel)"
 find . -not \( -path './.git' -prune \) -not \( -path './build' -prune \) \
-	| entr -cs 'scripts/build.sh && scripts/test.sh'
+	| entr -s 'clear && scripts/build.sh && scripts/test.sh'

tests/CMakeLists.txt

@@ -19,6 +19,7 @@ endfunction()
 add_test_suites(
   construct_tests.c
   convert_tests.c
+  desugar_tests.c
   fsa_tests.c
   integration_tests.c
   min_heap_tests.c

tests/construct_tests.c

@@ -34,13 +34,13 @@ static bool accepts(const fsa_t *nfa, const char *input)
 
 static void test_empty_expression(void)
 {
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_EMPTY;
+	terms[0].type = REGEX_TERM_EMPTY;
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
 	alternatives[0].count = alternatives[0].capacity = 1;
 	alternatives[0].contents = terms;
-	const parse_tree_t regex
+	const regex_t regex
 	    = { .count = 1, .capacity = 1, .contents = alternatives };
 
 	fsa_t fsa;
@@ -49,45 +49,20 @@ static void test_empty_expression(void)
 	ASSERT_TRUE(accepts(&fsa, ""));
 	ASSERT_FALSE(accepts(&fsa, "a"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
-	fsa_free(&fsa);
-}
-
-static void test_wildcard(void)
-{
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_WILDCARD;
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
-	alternatives[0].count = alternatives[0].capacity = 1;
-	alternatives[0].contents = terms;
-	const parse_tree_t regex
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
-
-	fsa_t fsa;
-	construct_nfa(&regex, &fsa);
-
-	ASSERT_TRUE(accepts(&fsa, "a"));
-	ASSERT_TRUE(accepts(&fsa, "b"));
-	ASSERT_TRUE(accepts(&fsa, "c"));
-	ASSERT_TRUE(accepts(&fsa, "d"));
-	ASSERT_FALSE(accepts(&fsa, ""));
-	ASSERT_FALSE(accepts(&fsa, "aa"));
-
-	parse_tree_free(&regex);
 	fsa_free(&fsa);
 }
 
 static void test_literal_expression(void)
 {
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_LITERAL;
+	terms[0].type = REGEX_TERM_LITERAL;
 	terms[0].literal = 'a';
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
 	alternatives[0].count = alternatives[0].capacity = 1;
 	alternatives[0].contents = terms;
-	const parse_tree_t regex
+	const regex_t regex
 	    = { .count = 1, .capacity = 1, .contents = alternatives };
 
 	fsa_t fsa;
@@ -96,27 +71,26 @@ static void test_literal_expression(void)
 	ASSERT_TRUE(accepts(&fsa, "a"));
 	ASSERT_FALSE(accepts(&fsa, "b"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
 	fsa_free(&fsa);
 }
 
 static void test_sequence(void)
 {
-	parse_term_t *terms = malloc(3 * sizeof(parse_term_t));
+	regex_term_t *terms = malloc(3 * sizeof(regex_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_LITERAL;
+	terms[0].type = REGEX_TERM_LITERAL;
 	terms[0].literal = 'a';
-	terms[1].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[1].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[1].type = PARSE_TERM_LITERAL;
+	terms[1].type = REGEX_TERM_LITERAL;
 	terms[1].literal = 'b';
-	terms[2].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[2].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[2].type = PARSE_TERM_LITERAL;
+	terms[2].type = REGEX_TERM_LITERAL;
 	terms[2].literal = 'c';
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
 	alternatives[0].count = alternatives[0].capacity = 3;
 	alternatives[0].contents = terms;
-	parse_tree_t regex
+	regex_t regex = { .count = 1, .capacity = 1, .contents = alternatives };
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
 
 	fsa_t fsa;
 	construct_nfa(&regex, &fsa);
@@ -127,25 +101,24 @@ static void test_sequence(void)
 	ASSERT_FALSE(accepts(&fsa, "d"));
 	ASSERT_FALSE(accepts(&fsa, "abcd"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
 	fsa_free(&fsa);
 }
 
 static void test_union(void)
 {
 	const char *literals = "abc";
-	parse_sequence_t *alternatives = malloc(3 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(3 * sizeof(regex_sequence_t));
 	for (int i = 0; i < 3; ++i) {
-		parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
+		regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
-		terms[0].quantifier = PARSE_QUANTIFIER_NONE;
+		terms[0].quantifier = REGEX_QUANTIFIER_NONE;
-		terms[0].type = PARSE_TERM_LITERAL;
+		terms[0].type = REGEX_TERM_LITERAL;
 		terms[0].literal = literals[i];
 
 		alternatives[i].count = alternatives[i].capacity = 1;
 		alternatives[i].contents = terms;
 	}
-	parse_tree_t regex
+	regex_t regex = { .count = 3, .capacity = 3, .contents = alternatives };
-	    = { .count = 3, .capacity = 3, .contents = alternatives };
 
 	fsa_t fsa;
 	construct_nfa(&regex, &fsa);
@@ -156,21 +129,20 @@ static void test_union(void)
 	ASSERT_FALSE(accepts(&fsa, "d"));
 	ASSERT_FALSE(accepts(&fsa, "aa"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
 	fsa_free(&fsa);
 }
 
 static void test_star(void)
 {
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_STAR;
+	terms[0].quantifier = REGEX_QUANTIFIER_STAR;
-	terms[0].type = PARSE_TERM_LITERAL;
+	terms[0].type = REGEX_TERM_LITERAL;
 	terms[0].literal = 'a';
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
 	alternatives[0].count = alternatives[0].capacity = 1;
 	alternatives[0].contents = terms;
-	parse_tree_t regex
+	regex_t regex = { .count = 1, .capacity = 1, .contents = alternatives };
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
 
 	fsa_t fsa;
 	construct_nfa(&regex, &fsa);
@@ -180,78 +152,29 @@ static void test_star(void)
 	ASSERT_TRUE(accepts(&fsa, "aaaaaa"));
 	ASSERT_FALSE(accepts(&fsa, "b"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
-	fsa_free(&fsa);
-}
-
-static void test_plus(void)
-{
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_PLUS;
-	terms[0].type = PARSE_TERM_LITERAL;
-	terms[0].literal = 'a';
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
-	alternatives[0].count = alternatives[0].capacity = 1;
-	alternatives[0].contents = terms;
-	parse_tree_t regex
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
-
-	fsa_t fsa;
-	construct_nfa(&regex, &fsa);
-
-	ASSERT_TRUE(accepts(&fsa, "a"));
-	ASSERT_TRUE(accepts(&fsa, "aaaaaa"));
-	ASSERT_FALSE(accepts(&fsa, ""));
-	ASSERT_FALSE(accepts(&fsa, "b"));
-
-	parse_tree_free(&regex);
-	fsa_free(&fsa);
-}
-
-static void test_qmark(void)
-{
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_QMARK;
-	terms[0].type = PARSE_TERM_LITERAL;
-	terms[0].literal = 'a';
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
-	alternatives[0].count = alternatives[0].capacity = 1;
-	alternatives[0].contents = terms;
-	parse_tree_t regex
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
-
-	fsa_t fsa;
-	construct_nfa(&regex, &fsa);
-
-	ASSERT_TRUE(accepts(&fsa, ""));
-	ASSERT_TRUE(accepts(&fsa, "a"));
-	ASSERT_FALSE(accepts(&fsa, "aa"));
-	ASSERT_FALSE(accepts(&fsa, "b"));
-
-	parse_tree_free(&regex);
 	fsa_free(&fsa);
 }
 
 static void test_subexpression(void)
 {
-	parse_term_t *inner_terms = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *inner_terms = malloc(1 * sizeof(regex_term_t));
-	inner_terms[0].quantifier = PARSE_QUANTIFIER_NONE;
+	inner_terms[0].quantifier = REGEX_QUANTIFIER_NONE;
-	inner_terms[0].type = PARSE_TERM_LITERAL;
+	inner_terms[0].type = REGEX_TERM_LITERAL;
 	inner_terms[0].literal = 'a';
-	parse_sequence_t *inner_alternatives
+	regex_sequence_t *inner_alternatives
-	    = malloc(1 * sizeof(parse_sequence_t));
+	    = malloc(1 * sizeof(regex_sequence_t));
 	inner_alternatives[0].count = inner_alternatives[0].capacity = 1;
 	inner_alternatives[0].contents = inner_terms;
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_SUBEXPR;
+	terms[0].type = REGEX_TERM_SUBEXPR;
 	terms[0].subexpr.count = terms[0].subexpr.capacity = 1;
 	terms[0].subexpr.contents = inner_alternatives;
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
 	alternatives[0].count = alternatives[0].capacity = 1;
 	alternatives[0].contents = terms;
-	parse_tree_t regex
+	regex_t regex = { .count = 1, .capacity = 1, .contents = alternatives };
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
 
 	fsa_t fsa;
 	construct_nfa(&regex, &fsa);
@@ -259,108 +182,42 @@ static void test_subexpression(void)
 	ASSERT_TRUE(accepts(&fsa, "a"));
 	ASSERT_FALSE(accepts(&fsa, "b"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
-	fsa_free(&fsa);
-}
-
-static void test_class(void)
-{
-	char *class_contents = malloc(3);
-	class_contents[0] = 'a';
-	class_contents[1] = 'b';
-	class_contents[2] = 'c';
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_CLASS;
-	terms[0].class.negated = false;
-	terms[0].class.count = terms[0].class.capacity = 3;
-	terms[0].class.contents = class_contents;
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
-	alternatives[0].count = alternatives[0].capacity = 1;
-	alternatives[0].contents = terms;
-	const parse_tree_t regex
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
-
-	fsa_t fsa;
-	construct_nfa(&regex, &fsa);
-
-	ASSERT_TRUE(accepts(&fsa, "a"));
-	ASSERT_TRUE(accepts(&fsa, "b"));
-	ASSERT_TRUE(accepts(&fsa, "c"));
-	ASSERT_FALSE(accepts(&fsa, ""));
-	ASSERT_FALSE(accepts(&fsa, "aa"));
-	ASSERT_FALSE(accepts(&fsa, "d"));
-
-	parse_tree_free(&regex);
-	fsa_free(&fsa);
-}
-
-static void test_negated_class(void)
-{
-	char *class_contents = malloc(3);
-	class_contents[0] = 'a';
-	class_contents[1] = 'b';
-	class_contents[2] = 'c';
-	parse_term_t *terms = malloc(1 * sizeof(parse_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_CLASS;
-	terms[0].class.negated = true;
-	terms[0].class.count = terms[0].class.capacity = 3;
-	terms[0].class.contents = class_contents;
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
-	alternatives[0].count = alternatives[0].capacity = 1;
-	alternatives[0].contents = terms;
-	const parse_tree_t regex
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
-
-	fsa_t fsa;
-	construct_nfa(&regex, &fsa);
-
-	ASSERT_TRUE(accepts(&fsa, "d"));
-	ASSERT_TRUE(accepts(&fsa, "e"));
-	ASSERT_FALSE(accepts(&fsa, "a"));
-	ASSERT_FALSE(accepts(&fsa, "b"));
-	ASSERT_FALSE(accepts(&fsa, "c"));
-	ASSERT_FALSE(accepts(&fsa, ""));
-	ASSERT_FALSE(accepts(&fsa, "aa"));
-
-	parse_tree_free(&regex);
 	fsa_free(&fsa);
 }
 
 static void test_sequence_containing_starred_union(void)
 {
 	// ab(c|d)*
-	parse_term_t *inner_terms0 = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *inner_terms0 = malloc(1 * sizeof(regex_term_t));
-	inner_terms0[0].quantifier = PARSE_QUANTIFIER_NONE;
+	inner_terms0[0].quantifier = REGEX_QUANTIFIER_NONE;
-	inner_terms0[0].type = PARSE_TERM_LITERAL;
+	inner_terms0[0].type = REGEX_TERM_LITERAL;
 	inner_terms0[0].literal = 'c';
-	parse_term_t *inner_terms1 = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *inner_terms1 = malloc(1 * sizeof(regex_term_t));
-	inner_terms1[0].quantifier = PARSE_QUANTIFIER_NONE;
+	inner_terms1[0].quantifier = REGEX_QUANTIFIER_NONE;
-	inner_terms1[0].type = PARSE_TERM_LITERAL;
+	inner_terms1[0].type = REGEX_TERM_LITERAL;
 	inner_terms1[0].literal = 'd';
-	parse_sequence_t *inner_alternatives
+	regex_sequence_t *inner_alternatives
-	    = malloc(2 * sizeof(parse_sequence_t));
+	    = malloc(2 * sizeof(regex_sequence_t));
 	inner_alternatives[0].count = inner_alternatives[0].capacity = 1;
 	inner_alternatives[0].contents = inner_terms0;
 	inner_alternatives[1].count = inner_alternatives[1].capacity = 1;
 	inner_alternatives[1].contents = inner_terms1;
-	parse_term_t *terms = malloc(3 * sizeof(parse_term_t));
+	regex_term_t *terms = malloc(3 * sizeof(regex_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_LITERAL;
+	terms[0].type = REGEX_TERM_LITERAL;
 	terms[0].literal = 'a';
-	terms[1].quantifier = PARSE_QUANTIFIER_NONE;
+	terms[1].quantifier = REGEX_QUANTIFIER_NONE;
-	terms[1].type = PARSE_TERM_LITERAL;
+	terms[1].type = REGEX_TERM_LITERAL;
 	terms[1].literal = 'b';
-	terms[2].quantifier = PARSE_QUANTIFIER_STAR;
+	terms[2].quantifier = REGEX_QUANTIFIER_STAR;
-	terms[2].type = PARSE_TERM_SUBEXPR;
+	terms[2].type = REGEX_TERM_SUBEXPR;
 	terms[2].subexpr.count = terms[2].subexpr.capacity = 2;
 	terms[2].subexpr.contents = inner_alternatives;
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
 	alternatives[0].count = alternatives[0].capacity = 3;
 	alternatives[0].contents = terms;
-	parse_tree_t regex
+	regex_t regex = { .count = 1, .capacity = 1, .contents = alternatives };
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
 
 	fsa_t fsa;
 	construct_nfa(&regex, &fsa);
@@ -376,7 +233,7 @@ static void test_sequence_containing_starred_union(void)
 	ASSERT_FALSE(accepts(&fsa, "d"));
 	ASSERT_FALSE(accepts(&fsa, "foo"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
 	fsa_free(&fsa);
 }
 
@@ -384,24 +241,23 @@ static void
 test_union_of_single_term_and_sequence_containing_starred_term(void)
 {
 	// a|b*c
-	parse_term_t *terms0 = malloc(1 * sizeof(parse_term_t));
+	regex_term_t *terms0 = malloc(1 * sizeof(regex_term_t));
-	terms0[0].quantifier = PARSE_QUANTIFIER_NONE;
+	terms0[0].quantifier = REGEX_QUANTIFIER_NONE;
-	terms0[0].type = PARSE_TERM_LITERAL;
+	terms0[0].type = REGEX_TERM_LITERAL;
 	terms0[0].literal = 'a';
-	parse_term_t *terms1 = malloc(2 * sizeof(parse_term_t));
+	regex_term_t *terms1 = malloc(2 * sizeof(regex_term_t));
-	terms1[0].quantifier = PARSE_QUANTIFIER_STAR;
+	terms1[0].quantifier = REGEX_QUANTIFIER_STAR;
-	terms1[0].type = PARSE_TERM_LITERAL;
+	terms1[0].type = REGEX_TERM_LITERAL;
 	terms1[0].literal = 'b';
-	terms1[1].quantifier = PARSE_QUANTIFIER_NONE;
+	terms1[1].quantifier = REGEX_QUANTIFIER_NONE;
-	terms1[1].type = PARSE_TERM_LITERAL;
+	terms1[1].type = REGEX_TERM_LITERAL;
 	terms1[1].literal = 'c';
-	parse_sequence_t *alternatives = malloc(2 * sizeof(parse_sequence_t));
+	regex_sequence_t *alternatives = malloc(2 * sizeof(regex_sequence_t));
 	alternatives[0].count = alternatives[0].capacity = 1;
 	alternatives[0].contents = terms0;
 	alternatives[1].count = alternatives[1].capacity = 2;
 	alternatives[1].contents = terms1;
-	parse_tree_t regex
+	regex_t regex = { .count = 2, .capacity = 2, .contents = alternatives };
-	    = { .count = 2, .capacity = 2, .contents = alternatives };
 
 	fsa_t fsa;
 	construct_nfa(&regex, &fsa);
@@ -413,49 +269,7 @@ test_union_of_single_term_and_sequence_containing_starred_term(void)
 	ASSERT_FALSE(accepts(&fsa, "foo"));
 	ASSERT_FALSE(accepts(&fsa, "ba"));
 
-	parse_tree_free(&regex);
+	regex_free(&regex);
-	fsa_free(&fsa);
-}
-
-static void test_sequence_of_subexpr_a_or_empty_and_b(void)
-{
-	// (a|ε)b
-	parse_term_t *inner_terms0 = malloc(1 * sizeof(parse_term_t));
-	inner_terms0[0].quantifier = PARSE_QUANTIFIER_NONE;
-	inner_terms0[0].type = PARSE_TERM_LITERAL;
-	inner_terms0[0].literal = 'a';
-	parse_term_t *inner_terms1 = malloc(1 * sizeof(parse_term_t));
-	inner_terms1[0].quantifier = PARSE_QUANTIFIER_NONE;
-	inner_terms1[0].type = PARSE_TERM_EMPTY;
-	parse_sequence_t *inner_alternatives
-	    = malloc(2 * sizeof(parse_sequence_t));
-	inner_alternatives[0].count = inner_alternatives[0].capacity = 1;
-	inner_alternatives[0].contents = inner_terms0;
-	inner_alternatives[1].count = inner_alternatives[1].capacity = 1;
-	inner_alternatives[1].contents = inner_terms1;
-	parse_term_t *terms = malloc(2 * sizeof(parse_term_t));
-	terms[0].quantifier = PARSE_QUANTIFIER_NONE;
-	terms[0].type = PARSE_TERM_SUBEXPR;
-	terms[0].subexpr.count = terms[0].subexpr.capacity = 2;
-	terms[0].subexpr.contents = inner_alternatives;
-	terms[1].quantifier = PARSE_QUANTIFIER_NONE;
-	terms[1].type = PARSE_TERM_LITERAL;
-	terms[1].literal = 'b';
-	parse_sequence_t *alternatives = malloc(1 * sizeof(parse_sequence_t));
-	alternatives[0].count = alternatives[0].capacity = 2;
-	alternatives[0].contents = terms;
-	parse_tree_t regex
-	    = { .count = 1, .capacity = 1, .contents = alternatives };
-
-	fsa_t fsa;
-	construct_nfa(&regex, &fsa);
-
-	ASSERT_TRUE(accepts(&fsa, "ab"));
-	ASSERT_TRUE(accepts(&fsa, "b"));
-	ASSERT_FALSE(accepts(&fsa, ""));
-	ASSERT_FALSE(accepts(&fsa, "a"));
-
-	parse_tree_free(&regex);
 	fsa_free(&fsa);
 }
 
@@ -466,20 +280,14 @@ int main(void)
 	// Base cases
 	test_empty_expression();
 	test_literal_expression();
-	test_wildcard();
 	test_sequence();
 	test_union();
 	test_star();
-	test_plus();
-	test_qmark();
 	test_subexpression();
-	test_class();
-	test_negated_class();
 
 	// Compound expressions
 	test_sequence_containing_starred_union();
 	test_union_of_single_term_and_sequence_containing_starred_term();
-	test_sequence_of_subexpr_a_or_empty_and_b();
 
 	return TESTING_END();
 }

tests/desugar_tests.c

@@ -0,0 +1,357 @@
+/*
+ * Copyright (c) Camden Dixie O'Brien
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+#include "desugar.h"
+#include "testing.h"
+
+#include <stddef.h>
+
+static void a_is_unchanged(void)
+{
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
+	terms[0].type = REGEX_TERM_LITERAL;
+	terms[0].literal = 'a';
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	ASSERT_EQ(1, t.contents[0].count);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ('a', t.contents[0].contents[0].literal);
+
+	regex_free(&t);
+}
+
+static void abc_is_unchanged(void)
+{
+	regex_term_t *terms = malloc(3 * sizeof(regex_term_t));
+	terms[0].type = REGEX_TERM_LITERAL;
+	terms[0].literal = 'a';
+	terms[1].type = REGEX_TERM_LITERAL;
+	terms[1].literal = 'b';
+	terms[2].type = REGEX_TERM_LITERAL;
+	terms[2].literal = 'c';
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 3;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	ASSERT_EQ(3, t.contents[0].count);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ('a', t.contents[0].contents[0].literal);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[1].type);
+	ASSERT_EQ('b', t.contents[0].contents[1].literal);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[2].type);
+	ASSERT_EQ('c', t.contents[0].contents[2].literal);
+
+	regex_free(&t);
+}
+
+static void a_star_is_unchanged(void)
+{
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_STAR;
+	terms[0].type = REGEX_TERM_LITERAL;
+	terms[0].literal = 'a';
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	ASSERT_EQ(1, t.contents[0].count);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_QUANTIFIER_STAR, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ('a', t.contents[0].contents[0].literal);
+
+	regex_free(&t);
+}
+
+static void a_or_b_or_c_is_unchanged(void)
+{
+	const char *literals = "abc";
+	regex_sequence_t *alternatives = malloc(3 * sizeof(regex_sequence_t));
+	for (int i = 0; i < 3; ++i) {
+		regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+		terms[0].quantifier = REGEX_QUANTIFIER_NONE;
+		terms[0].type = REGEX_TERM_LITERAL;
+		terms[0].literal = literals[i];
+
+		alternatives[i].count = alternatives[i].capacity = 1;
+		alternatives[i].contents = terms;
+	}
+	regex_t t = { .count = 3, .capacity = 3, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(3, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	for (int i = 0; i < 3; ++i) {
+		ASSERT_EQ(1, t.contents[i].count);
+		ASSERT_NOT_NULL(t.contents[i].contents);
+		ASSERT_EQ(
+		    REGEX_QUANTIFIER_NONE, t.contents[i].contents[0].quantifier);
+		ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[i].contents[0].type);
+		ASSERT_EQ(literals[i], t.contents[i].contents[0].literal);
+	}
+
+	regex_free(&t);
+}
+
+static void subexpr_a_is_unchanged(void)
+{
+	regex_term_t *inner_terms = malloc(1 * sizeof(regex_term_t));
+	inner_terms[0].quantifier = REGEX_QUANTIFIER_NONE;
+	inner_terms[0].type = REGEX_TERM_LITERAL;
+	inner_terms[0].literal = 'a';
+	regex_sequence_t *inner_alternatives
+	    = malloc(1 * sizeof(regex_sequence_t));
+	inner_alternatives[0].count = inner_alternatives[0].capacity = 1;
+	inner_alternatives[0].contents = inner_terms;
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
+	terms[0].type = REGEX_TERM_SUBEXPR;
+	terms[0].subexpr.count = terms[0].subexpr.capacity = 1;
+	terms[0].subexpr.contents = inner_alternatives;
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	ASSERT_EQ(1, t.contents[0].count);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, t.contents[0].contents[0].type);
+
+	const regex_t *inner = &t.contents[0].contents[0].subexpr;
+	ASSERT_EQ(1, inner->count);
+	ASSERT_NOT_NULL(inner->contents);
+	ASSERT_EQ(1, inner->contents[0].count);
+	ASSERT_NOT_NULL(inner->contents[0].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[0].contents[0].type);
+	ASSERT_EQ('a', inner->contents[0].contents[0].literal);
+
+	regex_free(&t);
+}
+
+static void a_plus_becomes_subexpr_aa_star(void)
+{
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_PLUS;
+	terms[0].type = REGEX_TERM_LITERAL;
+	terms[0].literal = 'a';
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	ASSERT_EQ(1, t.contents[0].count);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, t.contents[0].contents[0].type);
+
+	const regex_t *inner = &t.contents[0].contents[0].subexpr;
+	ASSERT_EQ(1, inner->count);
+	ASSERT_NOT_NULL(inner->contents);
+	ASSERT_EQ(2, inner->contents[0].count);
+	ASSERT_NOT_NULL(inner->contents[0].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[0].contents[0].type);
+	ASSERT_EQ('a', inner->contents[0].contents[0].literal);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_STAR, inner->contents[0].contents[1].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[0].contents[1].type);
+	ASSERT_EQ('a', inner->contents[0].contents[1].literal);
+
+	regex_free(&t);
+}
+
+static void a_qmark_becomes_subexpr_empty_or_a(void)
+{
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_QMARK;
+	terms[0].type = REGEX_TERM_LITERAL;
+	terms[0].literal = 'a';
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	ASSERT_EQ(1, t.contents[0].count);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, t.contents[0].contents[0].type);
+
+	const regex_t *inner = &t.contents[0].contents[0].subexpr;
+	ASSERT_EQ(2, inner->count);
+	ASSERT_NOT_NULL(inner->contents);
+	ASSERT_EQ(1, inner->contents[0].count);
+	ASSERT_NOT_NULL(inner->contents[0].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_EMPTY, inner->contents[0].contents[0].type);
+	ASSERT_EQ(1, inner->contents[1].count);
+	ASSERT_NOT_NULL(inner->contents[1].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[1].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[1].contents[0].type);
+	ASSERT_EQ('a', inner->contents[1].contents[0].literal);
+
+	regex_free(&t);
+}
+
+static void class_abc_becomes_subexpr_a_or_b_or_c(void)
+{
+	char *options = malloc(3 * sizeof(char));
+	options[0] = 'a';
+	options[1] = 'b';
+	options[2] = 'c';
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
+	terms[0].type = REGEX_TERM_CLASS;
+	terms[0].class.negated = false;
+	terms[0].class.count = terms[0].class.capacity = 3;
+	terms[0].class.contents = options;
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_NOT_NULL(t.contents);
+	ASSERT_EQ(1, t.contents[0].count);
+	ASSERT_NOT_NULL(t.contents[0].contents);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, t.contents[0].contents[0].type);
+
+	const regex_t *inner = &t.contents[0].contents[0].subexpr;
+	ASSERT_EQ(3, inner->count);
+	ASSERT_NOT_NULL(inner->contents);
+	ASSERT_EQ(1, inner->contents[0].count);
+	ASSERT_NOT_NULL(inner->contents[0].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[0].contents[0].type);
+	ASSERT_EQ('a', inner->contents[0].contents[0].literal);
+	ASSERT_EQ(1, inner->contents[1].count);
+	ASSERT_NOT_NULL(inner->contents[1].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[1].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[1].contents[0].type);
+	ASSERT_EQ('b', inner->contents[1].contents[0].literal);
+	ASSERT_EQ(1, inner->contents[2].count);
+	ASSERT_NOT_NULL(inner->contents[2].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[2].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[2].contents[0].type);
+	ASSERT_EQ('c', inner->contents[2].contents[0].literal);
+
+	regex_free(&t);
+}
+
+static void subexpr_a_qmark_becomes_subexpr_subexpr_empty_or_a(void)
+{
+	regex_term_t *inner_terms = malloc(1 * sizeof(regex_term_t));
+	inner_terms[0].quantifier = REGEX_QUANTIFIER_QMARK;
+	inner_terms[0].type = REGEX_TERM_LITERAL;
+	inner_terms[0].literal = 'a';
+	regex_sequence_t *inner_alternatives
+	    = malloc(1 * sizeof(regex_sequence_t));
+	inner_alternatives[0].count = inner_alternatives[0].capacity = 1;
+	inner_alternatives[0].contents = inner_terms;
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_NONE;
+	terms[0].type = REGEX_TERM_SUBEXPR;
+	terms[0].subexpr.count = terms[0].subexpr.capacity = 1;
+	terms[0].subexpr.contents = inner_alternatives;
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t t = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	desugar_regex(&t);
+
+	ASSERT_EQ(1, t.count);
+	ASSERT_EQ(1, t.contents[0].count);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, t.contents[0].contents[0].type);
+
+	const regex_t *inner;
+
+	inner = &t.contents[0].contents[0].subexpr;
+	ASSERT_EQ(1, inner->count);
+	ASSERT_EQ(1, inner->contents[0].count);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, inner->contents[0].contents[0].type);
+
+	inner = &inner->contents[0].contents[0].subexpr;
+	ASSERT_EQ(2, inner->count);
+	ASSERT_NOT_NULL(inner->contents);
+	ASSERT_EQ(1, inner->contents[0].count);
+	ASSERT_NOT_NULL(inner->contents[0].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_EMPTY, inner->contents[0].contents[0].type);
+	ASSERT_EQ(1, inner->contents[1].count);
+	ASSERT_NOT_NULL(inner->contents[1].contents);
+	ASSERT_EQ(
+	    REGEX_QUANTIFIER_NONE, inner->contents[1].contents[0].quantifier);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[1].contents[0].type);
+	ASSERT_EQ('a', inner->contents[1].contents[0].literal);
+
+	regex_free(&t);
+}
+
+int main(void)
+{
+	TESTING_BEGIN();
+	a_is_unchanged();
+	abc_is_unchanged();
+	a_star_is_unchanged();
+	a_or_b_or_c_is_unchanged();
+	subexpr_a_is_unchanged();
+	a_plus_becomes_subexpr_aa_star();
+	a_qmark_becomes_subexpr_empty_or_a();
+	class_abc_becomes_subexpr_a_or_b_or_c();
+	subexpr_a_qmark_becomes_subexpr_subexpr_empty_or_a();
+	return TESTING_END();
+}

tests/integration_tests.c

@@ -47,54 +47,11 @@ static void test_arbitrary_regex_1(void)
 	fsa_free(&dfa);
 }
 
-static void test_arbitrary_regex_2(void)
-{
-	fsa_t dfa;
-	const char *regex = "(l|wh)?[aeiou]+";
-	const bool success = compile(regex, strlen(regex), &dfa);
-	ASSERT_TRUE(success);
-	ASSERT_ACCEPTS(&dfa, "laaaa");
-	ASSERT_ACCEPTS(&dfa, "eeeee");
-	ASSERT_ACCEPTS(&dfa, "iii");
-	ASSERT_ACCEPTS(&dfa, "whooo");
-	ASSERT_ACCEPTS(&dfa, "u");
-	ASSERT_REJECTS(&dfa, "wh");
-	ASSERT_REJECTS(&dfa, "lxxx");
-	fsa_free(&dfa);
-}
-
-static void test_system_header_include_regex(void)
-{
-	fsa_t dfa;
-	const char *regex = "#include <[abcdefghijklmnopqrstuvwxyz]+\\.h>";
-	const bool success = compile(regex, strlen(regex), &dfa);
-	ASSERT_TRUE(success);
-	ASSERT_ACCEPTS(&dfa, "#include <stdio.h>");
-	ASSERT_REJECTS(&dfa, "#include \"foo.h\"");
-	fsa_free(&dfa);
-}
-
-static void test_quoted_string_regex(void)
-{
-	fsa_t dfa;
-	const char *regex = "'(\\\\'|[^'])*'";
-	const bool success = compile(regex, strlen(regex), &dfa);
-	ASSERT_TRUE(success);
-	ASSERT_ACCEPTS(&dfa, "''");
-	ASSERT_ACCEPTS(&dfa, "'foo bar baz'");
-	ASSERT_ACCEPTS(&dfa, "'foo \\'bar\\' baz'");
-	ASSERT_REJECTS(&dfa, "'foo 'bar' baz'");
-	fsa_free(&dfa);
-}
-
 int main(void)
 {
 	TESTING_BEGIN();
 	test_foo_or_bar_regex();
 	test_even_number_of_Is_regex();
 	test_arbitrary_regex_1();
-	test_arbitrary_regex_2();
-	test_system_header_include_regex();
-	test_quoted_string_regex();
 	return TESTING_END();
 }

tests/parse_tests.c

@@ -10,268 +10,268 @@
 
 static void a_has_1_alternative(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("a", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void a_pipe_b_has_2_alternatives(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("a|b", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(2, t.count);
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void a_pipe_b_pipe_c_has_3_alternatives(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("a|b|c", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(3, t.count);
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void a_is_parsed_as_unquantified_literal(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("a", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
 	ASSERT_EQ('a', t.contents[0].contents[0].literal);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void b_is_parsed_as_unquantified_literal(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("b", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
 	ASSERT_EQ('b', t.contents[0].contents[0].literal);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void abc_is_parsed_as_sequence_of_unquantified_literals(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("abc", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(3, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
 	ASSERT_EQ('a', t.contents[0].contents[0].literal);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[1].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[1].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[1].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[1].type);
 	ASSERT_EQ('b', t.contents[0].contents[1].literal);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[2].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[2].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[2].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[2].type);
 	ASSERT_EQ('c', t.contents[0].contents[2].literal);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void dot_is_parsed_as_unquantified_wildcard_term(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING(".", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_WILDCARD, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_WILDCARD, t.contents[0].contents[0].type);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void backslash_dot_is_parsed_as_unquantified_literal(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("\\.", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
 	ASSERT_EQ('.', t.contents[0].contents[0].literal);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void backslash_backslash_is_parsed_as_unquantified_literal(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("\\\\", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[0].type);
 	ASSERT_EQ('\\', t.contents[0].contents[0].literal);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void a_pipe_b_in_parens_is_parsed_as_subexpr_term(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("(a|b)", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_SUBEXPR, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, t.contents[0].contents[0].type);
 
-	const parse_tree_t *inner = &t.contents[0].contents[0].subexpr;
+	const regex_t *inner = &t.contents[0].contents[0].subexpr;
 	ASSERT_EQ(2, inner->count);
 
 	ASSERT_EQ(1, inner->contents[0].count);
 	ASSERT_EQ(
-	    PARSE_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, inner->contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[0].contents[0].type);
 	ASSERT_EQ('a', inner->contents[0].contents[0].literal);
 
 	ASSERT_EQ(1, inner->contents[1].count);
 	ASSERT_EQ(
-	    PARSE_QUANTIFIER_NONE, inner->contents[1].contents[0].quantifier);
+	    REGEX_QUANTIFIER_NONE, inner->contents[1].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, inner->contents[1].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[1].contents[0].type);
 	ASSERT_EQ('b', inner->contents[1].contents[0].literal);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void a_in_parens_b_is_parsed_as_sequence_with_subexpr_term(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("(a)b", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(2, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_SUBEXPR, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_SUBEXPR, t.contents[0].contents[0].type);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[1].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[1].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, t.contents[0].contents[1].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, t.contents[0].contents[1].type);
 	ASSERT_EQ('b', t.contents[0].contents[1].literal);
 
-	const parse_tree_t *inner = &t.contents[0].contents[0].subexpr;
+	const regex_t *inner = &t.contents[0].contents[0].subexpr;
 	ASSERT_EQ(1, inner->contents[0].count);
 	ASSERT_EQ(
-	    PARSE_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
+	    REGEX_QUANTIFIER_NONE, inner->contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_LITERAL, inner->contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_LITERAL, inner->contents[0].contents[0].type);
 	ASSERT_EQ('a', inner->contents[0].contents[0].literal);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void dot_star_is_parsed_as_star_quantified_wildcard(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING(".*", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_STAR, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_STAR, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_WILDCARD, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_WILDCARD, t.contents[0].contents[0].type);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void dot_plus_is_parsed_as_plus_quantified_wildcard(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING(".+", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_PLUS, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_PLUS, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_WILDCARD, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_WILDCARD, t.contents[0].contents[0].type);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void dot_question_mark_is_parsed_as_qmrk_quantified_wildcard(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING(".?", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_QMARK, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_QMARK, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_WILDCARD, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_WILDCARD, t.contents[0].contents[0].type);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void a_in_brackets_is_parsed_as_class_containing_only_a(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("[a]", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_CLASS, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_CLASS, t.contents[0].contents[0].type);
 	ASSERT_FALSE(t.contents[0].contents[0].class.negated);
 	ASSERT_EQ(1, t.contents[0].contents[0].class.count);
 	ASSERT_NOT_NULL(t.contents[0].contents[0].class.contents);
 	ASSERT_EQ('a', t.contents[0].contents[0].class.contents[0]);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 static void caret_a_in_brackets_parses_as_negated_class(void)
 {
-	parse_tree_t t;
+	regex_t t;
 	const int result = PARSE_EXPR_STRING("[^a]", &t);
 	ASSERT_NE(-1, result);
 	ASSERT_EQ(1, t.count);
 	ASSERT_NOT_NULL(t.contents);
 
 	ASSERT_EQ(1, t.contents[0].count);
-	ASSERT_EQ(PARSE_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
+	ASSERT_EQ(REGEX_QUANTIFIER_NONE, t.contents[0].contents[0].quantifier);
-	ASSERT_EQ(PARSE_TERM_CLASS, t.contents[0].contents[0].type);
+	ASSERT_EQ(REGEX_TERM_CLASS, t.contents[0].contents[0].type);
 	ASSERT_TRUE(t.contents[0].contents[0].class.negated);
 	ASSERT_EQ(1, t.contents[0].contents[0].class.count);
 	ASSERT_NOT_NULL(t.contents[0].contents[0].class.contents);
 	ASSERT_EQ('a', t.contents[0].contents[0].class.contents[0]);
 
-	parse_tree_free(&t);
+	regex_free(&t);
 }
 
 int main(void)