start signature help

9 files changed, 132 insertions, 31 deletions

diff --git a/autocomplete.c b/autocomplete.c
index 2955183..5045a3d 100644
--- a/autocomplete.c
+++ b/autocomplete.c
@@ -121,7 +121,7 @@ static void autocomplete_send_completion_request(Ted *ted, TextBuffer *buffer, B
 	request.data.completion = (LSPRequestCompletion) {
 		.position = {
 			.document = lsp_document_id(lsp, buffer->filename),
-			.pos = buffer_pos_to_lsp(buffer, pos)
+			.pos = buffer_pos_to_lsp_position(buffer, pos)
 		},
 		.context = {
 			.trigger_kind = lsp_trigger,
diff --git a/buffer.c b/buffer.c
index 7b569bd..9796eb5 100644
--- a/buffer.c
+++ b/buffer.c
@@ -1419,8 +1419,13 @@ static Status buffer_insert_lines(TextBuffer *buffer, u32 where, u32 number) {
 	return false;
 }
 
+LSPDocumentID buffer_lsp_document_id(TextBuffer *buffer) {
+	LSP *lsp = buffer_lsp(buffer);
+	return lsp_document_id(lsp, buffer->filename);
+}
+
 // LSP uses UTF-16 indices because Microsoft fucking loves UTF-16 and won't let it die
-LSPPosition buffer_pos_to_lsp(TextBuffer *buffer, BufferPos pos) {
+LSPPosition buffer_pos_to_lsp_position(TextBuffer *buffer, BufferPos pos) {
 	LSPPosition lsp_pos = {
 		.line = pos.line
 	};
@@ -1436,6 +1441,22 @@ LSPPosition buffer_pos_to_lsp(TextBuffer *buffer, BufferPos pos) {
 	return lsp_pos;
 }
 
+LSPDocumentPosition buffer_pos_to_lsp_document_position(TextBuffer *buffer, BufferPos pos) {
+	LSPDocumentPosition docpos = {
+		.document = buffer_lsp_document_id(buffer),
+		.pos = buffer_pos_to_lsp_position(buffer, pos)
+	};
+	return docpos;
+}
+
+LSPPosition buffer_cursor_pos_as_lsp_position(TextBuffer *buffer) {
+	return buffer_pos_to_lsp_position(buffer, buffer->cursor_pos);
+}
+
+LSPDocumentPosition buffer_cursor_pos_as_lsp_document_position(TextBuffer *buffer) {
+	return buffer_pos_to_lsp_document_position(buffer, buffer->cursor_pos);
+}
+
 static void buffer_send_lsp_did_change(LSP *lsp, TextBuffer *buffer, BufferPos pos,
 	u32 nchars_deleted, String32 new_text) {
 	if (!buffer_is_named_file(buffer))
@@ -1443,9 +1464,9 @@ static void buffer_send_lsp_did_change(LSP *lsp, TextBuffer *buffer, BufferPos p
 	LSPDocumentChangeEvent event = {0};
 	if (new_text.len > 0)
 		event.text = str32_to_utf8_cstr(new_text);
-	event.range.start = buffer_pos_to_lsp(buffer, pos);
+	event.range.start = buffer_pos_to_lsp_position(buffer, pos);
 	BufferPos pos_end = buffer_pos_advance(buffer, pos, nchars_deleted);
-	event.range.end = buffer_pos_to_lsp(buffer, pos_end);
+	event.range.end = buffer_pos_to_lsp_position(buffer, pos_end);
 	lsp_document_changed(lsp, buffer->filename, event);
 }
 
diff --git a/lsp-parse.c b/lsp-parse.c
index a6e932e..339c490 100644
--- a/lsp-parse.c
+++ b/lsp-parse.c
@@ -78,6 +78,28 @@ static bool parse_range(LSP *lsp, const JSON *json, JSONValue range_value, LSPRa
 }
 
 
+static uint32_t *parse_trigger_characters(const JSON *json, JSONArray trigger_chars) {
+	uint32_t *array = NULL;
+	arr_reserve(array, trigger_chars.len);
+	for (u32 i = 0; i < trigger_chars.len; ++i) {
+		char character[8] = {0};
+		json_string_get(json,
+			json_array_get_string(json, trigger_chars, i),
+			character,
+			sizeof character);
+		if (*character) {
+			// the fact that they're called "trigger characters" makes
+			// me think multi-character triggers aren't allowed
+			// even though that would be nice in some languages,
+			// e.g. "::"
+			char32_t c = 0;
+			unicode_utf8_to_utf32(&c, character, strlen(character));
+			if (c) arr_add(array, c);
+		}
+	}
+	return array;
+}
+
 static void parse_capabilities(LSP *lsp, const JSON *json, JSONObject capabilities) {
 	LSPCapabilities *cap = &lsp->capabilities;
 	
@@ -88,26 +110,19 @@ static void parse_capabilities(LSP *lsp, const JSON *json, JSONObject capabiliti
 		JSONObject completion = completion_value.val.object;
 		
 		JSONArray trigger_chars = json_object_get_array(json, completion, "triggerCharacters");
-		for (u32 i = 0; i < trigger_chars.len; ++i) {
-			char character[8] = {0};
-			json_string_get(json,
-				json_array_get_string(json, trigger_chars, i),
-				character,
-				sizeof character);
-			if (*character) {
-				char32_t c = 0;
-				unicode_utf8_to_utf32(&c, character, strlen(character));
-				// the fact that they're called "trigger characters" makes
-				// me think multi-character triggers aren't allowed
-				// even though that would be nice in some languages,
-				// e.g. "::"
-				if (c) {
-					arr_add(lsp->trigger_chars, c);
-				}
-			}
-		}
+		lsp->completion_trigger_chars = parse_trigger_characters(json, trigger_chars);
 	}
 	
+	// check SignatureHelpOptions
+	JSONValue signature_help_value = json_object_get(json, capabilities, "signatureHelpProvider");
+	if (signature_help_value.type == JSON_OBJECT) {
+		cap->signature_help_support = true;
+		JSONObject signature_help = signature_help_value.val.object;
+		JSONArray trigger_chars = json_object_get_array(json, signature_help, "triggerCharacters");
+		lsp->signature_help_trigger_chars = parse_trigger_characters(json, trigger_chars);
+		JSONArray retrigger_chars = json_object_get_array(json, signature_help, "retriggerCharacters");
+		lsp->signature_help_retrigger_chars = parse_trigger_characters(json, retrigger_chars);
+	}
 	
 	JSONObject workspace = json_object_get_object(json, capabilities, "workspace");
 	// check WorkspaceFoldersServerCapabilities
diff --git a/lsp-write.c b/lsp-write.c
index ffa5337..835cfce 100644
--- a/lsp-write.c
+++ b/lsp-write.c
@@ -251,6 +251,8 @@ static const char *lsp_request_method(LSPRequest *request) {
 		return "textDocument/didChange";
 	case LSP_REQUEST_COMPLETION:
 		return "textDocument/completion";
+	case LSP_REQUEST_SIGNATURE_HELP:
+		return "textDocument/signatureHelp";
 	case LSP_REQUEST_WORKSPACE_FOLDERS:
 		return "workspace/workspaceFolders";
 	case LSP_REQUEST_DID_CHANGE_WORKSPACE_FOLDERS:
@@ -275,6 +277,7 @@ static bool request_type_is_notification(LSPRequestType type) {
 	case LSP_REQUEST_SHOW_MESSAGE:
 	case LSP_REQUEST_LOG_MESSAGE:
 	case LSP_REQUEST_COMPLETION:
+	case LSP_REQUEST_SIGNATURE_HELP:
 	case LSP_REQUEST_WORKSPACE_FOLDERS:
 		return false;
 	}
@@ -386,6 +389,10 @@ static void write_request(LSP *lsp, LSPRequest *request) {
 						write_obj_end(o);
 						write_key_bool(o, "contextSupport", true);
 					write_obj_end(o);
+					write_key_obj_start(o, "signatureHelp");
+						// we don't have context support because sending the activeSignatureHelp member is annoying
+						//write_key_bool(o, "contextSupport", true);
+					write_obj_end(o);
 				write_obj_end(o);
 				write_key_obj_start(o, "workspace");
 					write_key_bool(o, "workspaceFolders", true);
diff --git a/lsp.c b/lsp.c
index a490aad..9ec7ad7 100644
--- a/lsp.c
+++ b/lsp.c
@@ -447,7 +447,9 @@ void lsp_free(LSP *lsp) {
 	
 	arr_free(lsp->workspace_folders);
 	
-	arr_free(lsp->trigger_chars);
+	arr_free(lsp->completion_trigger_chars);
+	arr_free(lsp->signature_help_trigger_chars);
+	arr_free(lsp->signature_help_retrigger_chars);
 	memset(lsp, 0, sizeof *lsp);
 	free(lsp);
 }
diff --git a/lsp.h b/lsp.h
index 5452dc2..1c75861 100644
--- a/lsp.h
+++ b/lsp.h
@@ -33,6 +33,7 @@ typedef enum {
 	LSP_REQUEST_DID_CLOSE, // textDocument/didClose
 	LSP_REQUEST_DID_CHANGE, // textDocument/didChange
 	LSP_REQUEST_COMPLETION, // textDocument/completion
+	LSP_REQUEST_SIGNATURE_HELP, // textDocument/signatureHelp
 	LSP_REQUEST_DID_CHANGE_WORKSPACE_FOLDERS, // workspace/didChangeWorkspaceFolders
 	
 	// server-to-client
@@ -82,12 +83,15 @@ typedef struct {
 	LSPPosition pos;
 } LSPDocumentPosition;
 
-typedef enum {
-	LSP_TRIGGER_NONE = 0, // not actually defined in LSP spec
-	LSP_TRIGGER_INVOKED = 1,
-	LSP_TRIGGER_CHARACTER = 2,
-	LSP_TRIGGER_INCOMPLETE = 3
-} LSPCompletionTriggerKind;
+
+// these triggers are used for completion context and signature help context.
+#define LSP_TRIGGER_NONE 0 // not actually defined in LSP spec
+#define LSP_TRIGGER_INVOKED 1
+#define LSP_TRIGGER_CHARACTER 2
+#define LSP_TRIGGER_INCOMPLETE 3
+#define LSP_TRIGGER_CONTENT_CHANGE 3
+typedef u8 LSPCompletionTriggerKind;
+typedef u8 LSPSignatureHelpTriggerKind;
 
 typedef struct {
 	LSPCompletionTriggerKind trigger_kind;
@@ -100,6 +104,10 @@ typedef struct {
 } LSPRequestCompletion;
 
 typedef struct {
+	LSPDocumentPosition position;
+} LSPRequestSignatureHelp;
+
+typedef struct {
 	LSPDocumentID *removed; // dynamic array
 	LSPDocumentID *added; // dynamic array
 } LSPRequestDidChangeWorkspaceFolders;
@@ -115,6 +123,7 @@ typedef struct {
 		LSPRequestDidClose close;
 		LSPRequestDidChange change;
 		LSPRequestCompletion completion;
+		LSPRequestSignatureHelp signature_help;
 		// LSP_REQUEST_SHOW_MESSAGE or LSP_REQUEST_LOG_MESSAGE
 		LSPRequestMessage message;
 		LSPRequestDidChangeWorkspaceFolders change_workspace_folders;
@@ -263,6 +272,7 @@ typedef struct {
 } LSPDocumentData;
 
 typedef struct {
+	bool signature_help_support;
 	bool completion_support;
 	// support for multiple root folders
 	// sadly, as of me writing this, clangd and rust-analyzer don't support this
@@ -316,7 +326,11 @@ typedef struct LSP {
 	//                never accessed in main thread before `initialized = true`.
 	LSPCapabilities capabilities;
 	// thread-safety: same as `capabilities`
-	char32_t *trigger_chars; // dynamic array of "trigger characters"
+	char32_t *completion_trigger_chars; // dynamic array
+	// thread-safety: same as `capabilities`
+	char32_t *signature_help_trigger_chars; // dynamic array
+	// thread-safety: same as `capabilities`
+	char32_t *signature_help_retrigger_chars; // dynamic array
 	SDL_mutex *workspace_folders_mutex;
 		LSPDocumentID *workspace_folders; // dynamic array of root directories of LSP workspace folders
 	SDL_mutex *error_mutex;
diff --git a/main.c b/main.c
index e10d6c3..3f028f6 100644
--- a/main.c
+++ b/main.c
@@ -5,6 +5,8 @@
      - hover
      - go to definition using LSP
      - find usages
+- go through signature help capabilities
+- separate signature-help setting (dont use trigger-characters)
 - check if there are any other non-optional/nice-to-have-support-for server-to-client requests
 - do something with lsp->error
 - document lsp.h and lsp.c.
@@ -138,6 +140,7 @@ bool tag_goto(Ted *ted, char const *tag);
 #include "tags.c"
 #include "menu.c"
 #include "autocomplete.c"
+#include "signature-help.c"
 #include "command.c"
 #include "config.c"
 #include "session.c"
@@ -768,13 +771,33 @@ int main(int argc, char **argv) {
 						char32_t last_char = 0;
 						unicode_utf8_to_utf32(&last_char, &text[last_code_point],
 							strlen(text) - last_code_point);
-						arr_foreach_ptr(lsp->trigger_chars, char32_t, c) {
+						arr_foreach_ptr(lsp->completion_trigger_chars, char32_t, c) {
 							if (*c == last_char) {
 								autocomplete_open(ted, last_char);
 								break;
 							}
 						}
 						
+						bool signature_help = false;
+						arr_foreach_ptr(lsp->signature_help_trigger_chars, char32_t, c) {
+							if (*c == last_char) {
+								signature_help = true;
+								break;
+							}
+						}
+						
+						if (ted->signature_help.open) {
+							arr_foreach_ptr(lsp->signature_help_retrigger_chars, char32_t, c) {
+								if (*c == last_char) {
+									signature_help = true;
+									break;
+								}
+							}
+						}
+						
+						if (signature_help)
+							signature_help_open(ted, last_char);
+						
 						if (settings->identifier_trigger_characters && is_word(last_char)
 							&& !is_digit(last_char))
 							autocomplete_open(ted, last_char);
diff --git a/signature-help.c b/signature-help.c
new file mode 100644
index 0000000..df8c564
--- /dev/null
+++ b/signature-help.c
@@ -0,0 +1,12 @@
+// deals with textDocument/signatureHelp LSP requests
+
+void signature_help_open(Ted *ted, char32_t trigger) {
+	(void)trigger; // for now we don't send context
+	TextBuffer *buffer = ted->active_buffer;
+	if (!buffer) return;
+	LSP *lsp = buffer_lsp(buffer);
+	LSPRequest request  = {.type = LSP_REQUEST_SIGNATURE_HELP};
+	LSPRequestSignatureHelp *s = &request.data.signature_help;
+	s->position = buffer_cursor_pos_as_lsp_document_position(buffer);
+	lsp_send_request(lsp, &request);
+}
diff --git a/ted.h b/ted.h
index 8d5d40c..7cfdbd4 100644
--- a/ted.h
+++ b/ted.h
@@ -417,6 +417,11 @@ typedef struct {
 	Rect rect; // rectangle where the autocomplete menu is (needed to avoid interpreting autocomplete clicks as other clicks)
 } Autocomplete;
 
+// "signature help" (LSP) is thing that shows the current parameter, etc.
+typedef struct {
+	bool open;
+} SignatureHelp;
+
 
 typedef struct Ted {
 	struct LSP *lsps[TED_LSP_MAX + 1];
@@ -463,6 +468,7 @@ typedef struct Ted {
 	bool find; // is the find or find+replace menu open?
 	bool replace; // is the find+replace menu open?
 	bool find_regex, find_case_sensitive; // find options
+	SignatureHelp signature_help;
 	u32 find_flags; // flags used last time search term was compiled
 	pcre2_code *find_code;
 	pcre2_match_data *find_match_data;
@@ -542,6 +548,7 @@ Settings *ted_active_settings(Ted *ted);
 Settings *ted_get_settings(Ted *ted, const char *path, Language lang);
 void ted_load_configs(Ted *ted, bool reloading);
 struct LSP *ted_get_lsp(Ted *ted, const char *path, Language lang);
+struct LSP *ted_active_lsp(Ted *ted);
 struct LSP *ted_get_lsp_by_id(Ted *ted, u32 id);
 static TextBuffer *find_search_buffer(Ted *ted);
 // first, we read all config files, then we parse them.