Start better documenting C API

Doxyfile

@@ -0,0 +1,39 @@
+# Doxyfile 1.9.5
+
+# This file describes the settings to be used by the documentation system
+# doxygen (www.doxygen.org) for a project.
+#
+# All text after a double hash (##) is considered a comment and is placed in
+# front of the TAG it is preceding.
+#
+# All text after a single hash (#) is considered a comment and will be ignored.
+# The format is:
+# TAG = value [value, ...]
+# For lists, items can also be appended using:
+# TAG += value [value, ...]
+# Values that contain spaces should be placed between quotes (\" \").
+#
+# Note:
+#
+# Use doxygen to compare the used configuration file with the template
+# configuration file:
+# doxygen -x [configFile]
+
+# Non-default options
+PROJECT_NAME           = "Prism"
+OUTPUT_DIRECTORY       = doc
+JAVADOC_AUTOBRIEF      = YES
+OPTIMIZE_OUTPUT_FOR_C  = YES
+EXTRACT_ALL            = YES
+INPUT                  = src src/enc src/util include include/prism include/prism/enc include/prism/util
+HTML_OUTPUT            = c
+
+# Default options we might want to edit in the future
+HTML_STYLESHEET        =
+HTML_COLORSTYLE        = AUTO_LIGHT
+GENERATE_LATEX         = NO
+
+# Default options we definitely want to edit in the future
+WARN_IF_UNDOCUMENTED   = NO
+WARN_NO_PARAMDOC       = NO
+WARN_AS_ERROR          = NO

include/prism/diagnostic.h

@@ -8,7 +8,11 @@
 #include <stdlib.h>
 #include <assert.h>
 
-// This struct represents a diagnostic found during parsing.
+/**
+ * This struct represents a diagnostic found during parsing.
+ *
+ * @extends pm_list_node_t
+ */
 typedef struct {
     pm_list_node_t node;
     const uint8_t *start;

include/prism/parser.h

@@ -243,16 +243,24 @@ typedef enum {
     PM_COMMENT___END__
 } pm_comment_type_t;
 
-// This is a node in the linked list of comments that we've found while parsing.
+/**
+ * This is a node in the linked list of comments that we've found while parsing.
+ *
+ * @extends pm_list_node_t
+ */
 typedef struct pm_comment {
     pm_list_node_t node;
     const uint8_t *start;
     const uint8_t *end;
     pm_comment_type_t type;
 } pm_comment_t;
 
-// This is a node in the linked list of magic comments that we've found while
-// parsing.
+/**
+ * This is a node in the linked list of magic comments that we've found while
+ * parsing.
+ *
+ * @extends pm_list_node_t
+ */
 typedef struct {
     pm_list_node_t node;
     const uint8_t *key_start;

include/prism/util/pm_string.h

@@ -19,44 +19,82 @@ typedef struct {
 
 #define PM_EMPTY_STRING ((pm_string_t) { .type = PM_STRING_CONSTANT, .source = NULL, .length = 0 })
 
-// Initialize a shared string that is based on initial input.
+/**
+ * Initialize a shared string that is based on initial input.
+ *
+ * @memberof pm_string_t
+ */
 void pm_string_shared_init(pm_string_t *string, const uint8_t *start, const uint8_t *end);
 
-// Initialize an owned string that is responsible for freeing allocated memory.
+/**
+ * Initialize an owned string that is responsible for freeing allocated memory.
+ *
+ * @memberof pm_string_t
+ */
 void pm_string_owned_init(pm_string_t *string, uint8_t *source, size_t length);
 
-// Initialize a constant string that doesn't own its memory source.
+/**
+ * Initialize a constant string that doesn't own its memory source.
+ *
+ * @memberof pm_string_t
+ */
 void pm_string_constant_init(pm_string_t *string, const char *source, size_t length);
 
-// Read the file indicated by the filepath parameter into source and load its
-// contents and size into the given pm_string_t.
-// The given pm_string_t should be freed using pm_string_free() when it is no longer used.
-//
-// We want to use demand paging as much as possible in order to avoid having to
-// read the entire file into memory (which could be detrimental to performance
-// for large files). This means that if we're on windows we'll use
-// `MapViewOfFile`, on POSIX systems that have access to `mmap` we'll use
-// `mmap`, and on other POSIX systems we'll use `read`.
+/**
+ * Read the file indicated by the filepath parameter into source and load its
+ * contents and size into the given `pm_string_t`. The given `pm_string_t`
+ * should be freed using `pm_string_free` when it is no longer used.
+ *
+ * We want to use demand paging as much as possible in order to avoid having to
+ * read the entire file into memory (which could be detrimental to performance
+ * for large files). This means that if we're on windows we'll use
+ * `MapViewOfFile`, on POSIX systems that have access to `mmap` we'll use
+ * `mmap`, and on other POSIX systems we'll use `read`.
+ *
+ * @memberof pm_string_t
+ */
 PRISM_EXPORTED_FUNCTION bool pm_string_mapped_init(pm_string_t *string, const char *filepath);
 
-// Returns the memory size associated with the string.
+/**
+ * Returns the memory size associated with the string.
+ *
+ * @memberof pm_string_t
+ */
 size_t pm_string_memsize(const pm_string_t *string);
 
-// Ensure the string is owned. If it is not, then reinitialize it as owned and
-// copy over the previous source.
+/**
+ * Ensure the string is owned. If it is not, then reinitialize it as owned and
+ * copy over the previous source.
+ *
+ * @memberof pm_string_t
+ */
 void pm_string_ensure_owned(pm_string_t *string);
 
-// Returns the length associated with the string.
+/**
+ * Returns the length associated with the string.
+ *
+ * @memberof pm_string_t
+ */
 PRISM_EXPORTED_FUNCTION size_t pm_string_length(const pm_string_t *string);
 
-// Returns the start pointer associated with the string.
+/**
+ * Returns the start pointer associated with the string.
+ *
+ * @memberof pm_string_t
+ */
 PRISM_EXPORTED_FUNCTION const uint8_t * pm_string_source(const pm_string_t *string);
 
-// Free the associated memory of the given string.
+/**
+ * Free the associated memory of the given string.
+ *
+ * @memberof pm_string_t
+ */
 PRISM_EXPORTED_FUNCTION void pm_string_free(pm_string_t *string);
 
-// Returns the size of the pm_string_t struct. This is necessary to allocate the
-// correct amount of memory in the FFI backend.
+/**
+ * Returns the size of the pm_string_t struct. This is necessary to allocate the
+ * correct amount of memory in the FFI backend.
+ */
 PRISM_EXPORTED_FUNCTION size_t pm_string_sizeof(void);
 
 #endif // PRISM_STRING_H

rakelib/rdoc.rake

@@ -5,7 +5,7 @@ require "rdoc/task"
 RDoc::Task.new do |rdoc|
   rdoc.main = "README.md"
   rdoc.markup = "markdown"
-  rdoc.rdoc_dir = "doc"
+  rdoc.rdoc_dir = "doc/ruby"
 
   rdoc.options << "--all"
   rdoc.options << "--coverage-report"

src/prism.c

@@ -1,5 +1,104 @@
 #include "prism.h"
 
+/**
+ * @mainpage
+ *
+ * Prism is a parser for the Ruby programming language. It is designed to be
+ * portable, error tolerant, and maintainable. It is written in C99 and has no
+ * dependencies. It is currently being integrated into
+ * [CRuby](https://github.com/ruby/ruby),
+ * [JRuby](https://github.com/jruby/jruby),
+ * [TruffleRuby](https://github.com/oracle/truffleruby),
+ * [Sorbet](https://github.com/sorbet/sorbet), and
+ * [Syntax Tree](https://github.com/ruby-syntax-tree/syntax_tree).
+ *
+ * @section getting-started Getting started
+ *
+ * If you're vendoring this project and compiling it statically then as long as
+ * you have a C99 compiler you will be fine. If you're linking against it as
+ * shared library, then you should compile with `-fvisibility=hidden` and
+ * `-DPRISM_EXPORT_SYMBOLS` to tell prism to make only its public interface
+ * visible.
+ *
+ * @section parsing Parsing
+ * 
+ * In order to parse Ruby code, the structures and functions that you're going
+ * to want to use and be aware of are:
+ *
+ * * @ref pm_parser_t - the main parser structure
+ * * @ref pm_parser_init - initialize a parser
+ * * @ref pm_parse - parse and return the root node
+ * * @ref pm_node_destroy - deallocate the root node returned by `pm_parse`
+ * * @ref pm_parser_free - free the internal memory of the parser
+ *
+ * Putting all of this together would look something like:
+ *
+ * ```c
+ * void parse(const uint8_t *source, size_t length) {
+ *     pm_parser_t parser;
+ *     pm_parser_init(&parser, source, length, NULL);
+ *
+ *     pm_node_t *root = pm_parse(&parser);
+ *     printf("PARSED!\n");
+ *
+ *     pm_node_destroy(root);
+ *     pm_parser_free(&parser);
+ * }
+ * ```
+ *
+ * All of the nodes "inherit" from `pm_node_t` by embedding those structures as
+ * their first member. This means you can downcast and upcast any node in the
+ * tree to a `pm_node_t`.
+ *
+ * @section serializing Serializing
+ *
+ * Prism provides the ability to serialize the AST and its related metadata into
+ * a binary format. This format is designed to be portable to different
+ * languages and runtimes so that you only need to make one FFI call in order to
+ * parse Ruby code. The structures and functions that you're going to want to
+ * use and be aware of are:
+ *
+ * * @ref pm_buffer_t - a small buffer object that will hold the serialized AST
+ * * @ref pm_buffer_free - free the memory associated with the buffer
+ * * @ref pm_serialize - serialize the AST into a buffer
+ * * @ref pm_parse_serialize - parse and serialize the AST into a buffer
+ *
+ * Putting all of this together would look something like:
+ *
+ * ```c
+ * void serialize(const uint8_t *source, size_t length) {
+ *     pm_buffer_t buffer = { 0 };
+ *
+ *     pm_parse_serialize(source, length, &buffer, NULL);
+ *     printf("SERIALIZED!\n");
+ *
+ *     pm_buffer_free(&buffer);
+ * }
+ * ```
+ *
+ * @section inspecting Inspecting
+ *
+ * Prism provides the ability to inspect the AST by pretty-printing nodes. You
+ * can do this with the `pm_prettyprint` function, which you would use like:
+ *
+ * ```c
+ * void prettyprint(const uint8_t *source, size_t length) {
+ *     pm_parser_t parser;
+ *     pm_parser_init(&parser, source, length, NULL);
+ *
+ *     pm_node_t *root = pm_parse(&parser);
+ *     pm_buffer_t buffer = { 0 };
+ *
+ *     pm_prettyprint(&buffer, &parser, root);
+ *     printf("*.s%\n", (int) buffer.length, buffer.value);
+ *
+ *     pm_buffer_free(&buffer);
+ *     pm_node_destroy(root);
+ *     pm_parser_free(&parser);
+ * }
+ * ```
+ */
+
 // The prism version and the serialization format.
 const char *
 pm_version(void) {
@@ -15716,7 +15815,9 @@ pm_parser_free(pm_parser_t *parser) {
     }
 }
 
-// Parse the Ruby source associated with the given parser and return the tree.
+/**
+ * Parse the Ruby source associated with the given parser and return the tree.
+ */
 PRISM_EXPORTED_FUNCTION pm_node_t *
 pm_parse(pm_parser_t *parser) {
     return parse_program(parser);