PowerShell: use keyword api

This commit reverts the keyword type that was removed in a previous PR
and use keyword api.

Close universal-ctags#3479

parsers/powershell.c

@@ -57,8 +57,7 @@ typedef enum eTokenType {
 	TOKEN_SEMICOLON,
 	TOKEN_COLON,
 	TOKEN_COMMA,
-	TOKEN_KEYWORD_FUNCTION,
-	TOKEN_KEYWORD_CLASS,
+	TOKEN_KEYWORD,
 	TOKEN_OPEN_PAREN,
 	TOKEN_OPERATOR,
 	TOKEN_IDENTIFIER,
@@ -72,8 +71,24 @@ typedef enum eTokenType {
 	TOKEN_VARIABLE
 } tokenType;
 
+enum {
+	KEYWORD_function,
+	KEYWORD_filter,
+	KEYWORD_class,
+};
+
+/* We need an integer that is not an unsigned to allow KEYWORD_NONE. */
+typedef int keywordId;
+
+static const keywordTable PowerShellKeywordTable[] = {
+	{ "function",	KEYWORD_function },
+	{ "filter",		KEYWORD_filter },
+	{ "class",		KEYWORD_class },
+};
+
 typedef struct {
 	tokenType		type;
+	keywordId		keyword;
 	vString *		string;
 	vString *		scope;
 	unsigned long	lineNumber;
@@ -163,6 +178,7 @@ static tokenInfo *newToken (void)
 	tokenInfo *const token = xMalloc (1, tokenInfo);
 
 	token->type			= TOKEN_UNDEFINED;
+	token->keyword		= KEYWORD_NONE;
 	token->string		= vStringNew ();
 	token->scope		= vStringNew ();
 	token->lineNumber   = getInputLineNumber ();
@@ -229,17 +245,6 @@ static void parseIdentifier (vString *const string, const int firstChar)
 	ungetcToInputFile (c);
 }
 
-static bool isTokenFunction (vString *const name)
-{
-	return (strcasecmp (vStringValue (name), "function") == 0 ||
-			strcasecmp (vStringValue (name), "filter") == 0);
-}
-
-static bool isTokenClass (vString *const name)
-{
-	return strcasecmp (vStringValue (name), "class") == 0;
-}
-
 static bool isSpace (int c)
 {
 	return (c == '\t' || c == ' ' || c == '\v' ||
@@ -377,12 +382,12 @@ static void readToken (tokenInfo *const token)
 			else
 			{
 				parseIdentifier (token->string, c);
-				if (isTokenFunction (token->string))
-					token->type = TOKEN_KEYWORD_FUNCTION;
-				else if (isTokenClass (token->string))
-					token->type = TOKEN_KEYWORD_CLASS;
-				else
+				token->keyword = lookupCaseKeyword (
+						vStringValue (token->string), getInputLanguage ());
+				if (token->keyword == KEYWORD_NONE)
 					token->type = TOKEN_IDENTIFIER;
+				else
+					token->type = TOKEN_KEYWORD;
 			}
 			break;
 	}
@@ -619,12 +624,20 @@ static void enterScope (tokenInfo *const parentToken,
 				enterScope (token, NULL, KIND_GHOST_INDEX);
 				break;
 
-			case TOKEN_KEYWORD_FUNCTION:
-				readNext = parseFunction (token);
-				break;
+			case TOKEN_KEYWORD:
+				switch (token->keyword)
+				{
+					case KEYWORD_function:
+					case KEYWORD_filter:
+						readNext = parseFunction (token);
+						break;
 
-			case TOKEN_KEYWORD_CLASS:
-				readNext = parseClass (token);
+					case KEYWORD_class:
+						readNext = parseClass (token);
+						break;
+
+					default: break;
+				}
 				break;
 
 			case TOKEN_VARIABLE:
@@ -664,5 +677,7 @@ extern parserDefinition* PowerShellParser (void)
 	def->kindCount  = ARRAY_SIZE (PowerShellKinds);
 	def->extensions = extensions;
 	def->parser     = findPowerShellTags;
+	def->keywordTable = PowerShellKeywordTable;
+	def->keywordCount = ARRAY_SIZE (PowerShellKeywordTable);
 	return def;
 }