Better examples

4 files changed, 123 insertions, 17 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 69291e6..0c81004 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,9 +14,12 @@ set_target_properties(pom-shared PROPERTIES OUTPUT_NAME pom)
 add_executable(tests tests/errors.c tests/location.c tests/parsing.c tests/interpretation.c tests/main.c)
 target_include_directories(tests PRIVATE .)
 target_link_libraries(tests pom)
-add_executable(read_conf examples/read_conf.c)
-target_include_directories(read_conf PRIVATE .)
-target_link_libraries(read_conf pom)
+add_executable(example_read_conf examples/read_conf.c)
+target_include_directories(example_read_conf PRIVATE .)
+target_link_libraries(example_read_conf pom)
+add_executable(example_custom_alloc examples/custom_alloc.c)
+target_include_directories(example_custom_alloc PRIVATE .)
+target_link_libraries(example_custom_alloc pom)
 
 install(TARGETS pom pom-shared DESTINATION lib)
 install(FILES pom.pc DESTINATION lib)
diff --git a/examples/conf.pom b/examples/conf.pom
index 6011308..fe9fe2f 100644
--- a/examples/conf.pom
+++ b/examples/conf.pom
@@ -1 +1,17 @@
-things = \,,,76
+indentation-type = tabs
+show-line-numbers = yes
+tab-size = 4
+font-size = "18"
+
+[file-extensions]
+C = .c
+Cpp = .cpp, .h, .hpp
+
+[plug-in.edit-over-ssh]
+path = ~/misc/edit-over-ssh.so
+enabled = yes
+
+[plug-in.wrap-text]
+path = ~/misc/wrap_text_v3.5.7.so
+enabled = no
+
diff --git a/examples/custom_alloc.c b/examples/custom_alloc.c
new file mode 100644
index 0000000..42843ce
--- /dev/null
+++ b/examples/custom_alloc.c
@@ -0,0 +1,93 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdalign.h>
+#include <stddef.h>
+#include <string.h>
+
+#include <pom.h>
+
+// Custom memory allocation functions
+typedef struct {
+	uint64_t allocations, frees;
+	size_t memory_used;
+	alignas(max_align_t) char memory[100000];
+} Memory;
+static void *my_calloc(void *udata, size_t nmemb, size_t sz) {
+	Memory *my_memory = udata;
+	char *mem = (char *)my_memory->memory + my_memory->memory_used;
+	size_t new_memory_used = my_memory->memory_used;
+	while ((uintptr_t)mem & 7)
+		mem++, new_memory_used++;
+	new_memory_used += 8 + nmemb * sz;
+	if (new_memory_used > sizeof my_memory->memory) {
+		// out of memory: return NULL
+		return NULL;
+	}
+	my_memory->allocations++;
+	my_memory->memory_used = new_memory_used;
+	// store size of allocation
+	*(uint64_t *)mem = nmemb * sz;
+	return mem + sizeof (uint64_t);
+}
+static void my_free(void *udata, void *ptr) {
+	if (!ptr) {
+		// free must do nothing when null pointer is passed
+		return;
+	}
+	Memory *my_memory = udata;
+	my_memory->frees++;
+}
+
+static void *my_realloc(void *udata, void *ptr, size_t new_size) {
+	if (!ptr) {
+		// realloc(ptr = NULL) is equivalent to malloc
+		return my_calloc(udata, new_size, 1);
+	}
+	// inefficient but correct realloc implementation:
+	//  just free the old memory and allocate brand new memory
+	size_t old_size = ((uint64_t *)ptr)[-1];
+	void *new_ptr = my_calloc(udata, new_size, 1);
+	if (!new_ptr) {
+		// out-of-memory: return NULL
+		return NULL;
+	}
+	memcpy(new_ptr, ptr, old_size);
+	my_free(udata, ptr);
+	return new_ptr;
+}
+
+int main(void) {
+	pom_error *error;
+	pom_settings settings = {0};
+	// set allocation functions
+	settings.calloc = my_calloc;
+	settings.realloc = my_realloc;
+	settings.free = my_free;
+	static Memory my_memory;
+	// set udata pointer which is passed to the functions
+	settings.allocator_udata = &my_memory;
+
+	pom_conf *conf = pom_load_string(&settings, "conf.pom",
+		"foo = bar\n"
+		"[core]\n"
+		"list = 1,6,78,9\n",
+		 &error);
+	if (!conf) {
+		pom_error_print(error);
+		// error must be freed with custom allocation function
+		my_free(&my_memory, error);
+		return EXIT_FAILURE;
+	}
+	char **list = pom_conf_get_list(conf, "core.list");
+	for (size_t i = 0; list[i]; i++)
+		printf("- %s\n",list[i]);
+	// lists must be freed with custom allocation function
+	my_free(&my_memory, list);
+	pom_conf_free(conf);
+	if (my_memory.allocations != my_memory.frees) {
+		// if this ever happens, it's a bug in libpom
+		fprintf(stderr, "libpom is leaking memory!!!\n");
+		return EXIT_FAILURE;
+	}
+	return 0;
+}
diff --git a/examples/read_conf.c b/examples/read_conf.c
index d96e190..8f290f6 100644
--- a/examples/read_conf.c
+++ b/examples/read_conf.c
@@ -1,24 +1,18 @@
 #include <stdlib.h>
-#include <string.h>
-#include <inttypes.h>
-
 #include <pom.h>
 
-int main(int argc, char **argv) {
+int main(void) {
 	pom_error *error;
-	pom_settings settings = {0};
-	strcpy(settings.error_lang, "fr");
-	pom_conf *conf = pom_load_path(&settings, argc >= 2 ? argv[1] : "conf.pom", &error);
+	pom_conf *conf = pom_load_path(NULL, "conf.pom", &error);
 	if (!conf) {
 		pom_error_print(error);
 		free(error);
 		return EXIT_FAILURE;
 	}
-	char **list = pom_conf_get_list(conf, "things");
-	for (size_t i = 0; list[i]; i++) {
-		printf("%s\n",list[i]);
-	}
-	free(list);
-	pom_conf_print(conf);
+	const char *indentation_type = pom_conf_get(conf, "indentation-type");
+	if (indentation_type)
+		printf("Indenting with %s\n", indentation_type);
+	else
+		printf("No indentation type set!\n");
 	pom_conf_free(conf);
 }