| Copyright | Will Thompson and Iñaki García Etxebarria |
|---|---|
| License | LGPL-2.1 |
| Maintainer | Iñaki García Etxebarria |
| Safe Haskell | Safe-Inferred |
| Language | Haskell2010 |
GI.GLib.Structs.MarkupParseContext
Description
A parse context is used to parse a stream of bytes that you expect to contain marked-up text.
See markupParseContextNew, MarkupParser, and so on for more details.
Synopsis
- newtype MarkupParseContext = MarkupParseContext (ManagedPtr MarkupParseContext)
- markupParseContextEndParse :: (HasCallStack, MonadIO m) => MarkupParseContext -> m ()
- markupParseContextFree :: (HasCallStack, MonadIO m) => MarkupParseContext -> m ()
- markupParseContextGetElement :: (HasCallStack, MonadIO m) => MarkupParseContext -> m Text
- markupParseContextGetElementStack :: (HasCallStack, MonadIO m) => MarkupParseContext -> m [Text]
- markupParseContextGetPosition :: (HasCallStack, MonadIO m) => MarkupParseContext -> m (Int32, Int32)
- markupParseContextGetUserData :: (HasCallStack, MonadIO m) => MarkupParseContext -> m (Ptr ())
- markupParseContextNew :: (HasCallStack, MonadIO m) => MarkupParser -> [MarkupParseFlags] -> Ptr () -> DestroyNotify -> m MarkupParseContext
- markupParseContextParse :: (HasCallStack, MonadIO m) => MarkupParseContext -> Text -> Int64 -> m ()
- markupParseContextPop :: (HasCallStack, MonadIO m) => MarkupParseContext -> m (Ptr ())
- markupParseContextPush :: (HasCallStack, MonadIO m) => MarkupParseContext -> MarkupParser -> Ptr () -> m ()
- markupParseContextRef :: (HasCallStack, MonadIO m) => MarkupParseContext -> m MarkupParseContext
- markupParseContextUnref :: (HasCallStack, MonadIO m) => MarkupParseContext -> m ()
Exported types
newtype MarkupParseContext Source #
Memory-managed wrapper type.
Constructors
| MarkupParseContext (ManagedPtr MarkupParseContext) |
Instances
Methods
Click to display all available methods, including inherited ones
Methods
endParse, free, parse, pop, push, ref, unref.
Getters
getElement, getElementStack, getPosition, getUserData.
Setters
None.
endParse
markupParseContextEndParse Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m () | (Can throw |
Signals to the MarkupParseContext that all data has been fed into the parse context with markupParseContextParse.
This function reports an error if the document isn't complete, for example if elements are still open.
free
markupParseContextFree Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m () |
Frees a MarkupParseContext.
This function can't be called from inside one of the MarkupParser functions or while a subparser is pushed.
getElement
markupParseContextGetElement Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m Text | Returns: the name of the currently open element, or |
Retrieves the name of the currently open element.
If called from the start_element or end_element handlers this will give the element_name as passed to those functions. For the parent elements, see markupParseContextGetElementStack.
Since: 2.2
getElementStack
markupParseContextGetElementStack Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m [Text] | Returns: the element stack, which must not be modified |
Retrieves the element stack from the internal state of the parser.
The returned SList is a list of strings where the first item is the currently open tag (as would be returned by markupParseContextGetElement) and the next item is its immediate parent.
This function is intended to be used in the start_element and end_element handlers where markupParseContextGetElement would merely return the name of the element that is being processed.
Since: 2.16
getPosition
markupParseContextGetPosition Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m (Int32, Int32) |
Retrieves the current line number and the number of the character on that line. Intended for use in error messages; there are no strict semantics for what constitutes the "current" line number other than "the best number we could come up with for error messages."
getUserData
markupParseContextGetUserData Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m (Ptr ()) | Returns: the provided user_data. The returned data belongs to the markup context and will be freed when |
Returns the user_data associated with context.
This will either be the user_data that was provided to markupParseContextNew or to the most recent call of markupParseContextPush.
Since: 2.18
new
markupParseContextNew Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParser |
|
| -> [MarkupParseFlags] |
|
| -> Ptr () |
|
| -> DestroyNotify |
|
| -> m MarkupParseContext | Returns: a new |
Creates a new parse context. A parse context is used to parse marked-up documents. You can feed any number of documents into a context, as long as no errors occur; once an error occurs, the parse context can't continue to parse text (you have to free it and create a new parse context).
parse
markupParseContextParse Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> Text |
|
| -> Int64 |
|
| -> m () | (Can throw |
Feed some data to the MarkupParseContext.
The data need not be valid UTF-8; an error will be signaled if it's invalid. The data need not be an entire document; you can feed a document into the parser incrementally, via multiple calls to this function. Typically, as you receive data from a network connection or file, you feed each received chunk of data into this function, aborting the process if an error occurs. Once an error is reported, no further data may be fed to the MarkupParseContext; all errors are fatal.
pop
markupParseContextPop Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m (Ptr ()) | Returns: the user data passed to |
Completes the process of a temporary sub-parser redirection.
This function exists to collect the user_data allocated by a matching call to markupParseContextPush. It must be called in the end_element handler corresponding to the start_element handler during which markupParseContextPush was called. You must not call this function from the error callback -- the userData is provided directly to the callback in that case.
This function is not intended to be directly called by users interested in invoking subparsers. Instead, it is intended to be used by the subparsers themselves to implement a higher-level interface.
Since: 2.18
push
markupParseContextPush Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> MarkupParser |
|
| -> Ptr () |
|
| -> m () |
Temporarily redirects markup data to a sub-parser.
This function may only be called from the start_element handler of a MarkupParser. It must be matched with a corresponding call to markupParseContextPop in the matching end_element handler (except in the case that the parser aborts due to an error).
All tags, text and other data between the matching tags is redirected to the subparser given by parser. userData is used as the user_data for that parser. userData is also passed to the error callback in the event that an error occurs. This includes errors that occur in subparsers of the subparser.
The end tag matching the start tag for which this call was made is handled by the previous parser (which is given its own user_data) which is why markupParseContextPop is provided to allow "one last access" to the userData provided to this function. In the case of error, the userData provided here is passed directly to the error callback of the subparser and markupParseContextPop should not be called. In either case, if userData was allocated then it ought to be freed from both of these locations.
This function is not intended to be directly called by users interested in invoking subparsers. Instead, it is intended to be used by the subparsers themselves to implement a higher-level interface.
As an example, see the following implementation of a simple parser that counts the number of tags encountered.
C code
typedef struct { gint tag_count; } CounterData; static void counter_start_element (GMarkupParseContext *context, const gchar *element_name, const gchar **attribute_names, const gchar **attribute_values, gpointer user_data, GError **error) { CounterData *data = user_data; data->tag_count++; } static void counter_error (GMarkupParseContext *context, GError *error, gpointer user_data) { CounterData *data = user_data; g_slice_free (CounterData, data); } static GMarkupParser counter_subparser = { counter_start_element, NULL, NULL, NULL, counter_error };In order to allow this parser to be easily used as a subparser, the following interface is provided:
C code
void start_counting (GMarkupParseContext *context) { CounterData *data = g_slice_new (CounterData); data->tag_count = 0; g_markup_parse_context_push (context, &counter_subparser, data); } gint end_counting (GMarkupParseContext *context) { CounterData *data = g_markup_parse_context_pop (context); int result; result = data->tag_count; g_slice_free (CounterData, data); return result; }The subparser would then be used as follows:
C code
static void start_element (context, element_name, ...) { if (strcmp (element_name, "count-these") == 0) start_counting (context); // else, handle other tags... } static void end_element (context, element_name, ...) { if (strcmp (element_name, "count-these") == 0) g_print ("Counted %d tags\n", end_counting (context)); // else, handle other tags... }Since: 2.18
ref
markupParseContextRef Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m MarkupParseContext | Returns: the same |
Increases the reference count of context.
Since: 2.36
unref
markupParseContextUnref Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => MarkupParseContext |
|
| -> m () |
Decreases the reference count of context. When its reference count drops to 0, it is freed.
Since: 2.36