Merge: Prefix grammar

Update of the grammar to support the enhancement of literal strings and chars via prefixes (see issue #1734)

Pull-Request: #1851
Reviewed-by: Jean Privat <jean@pryen.org>

Author: privat

lib/markdown/markdown.nit

@@ -417,7 +417,7 @@ class MarkdownProcessor
 			end
 		else if c == '_' then
 			if c1 == '_' then
-				if c0 != ' ' or c2 != ' 'then
+				if c0 != ' ' or c2 != ' ' then
 					return new TokenStrongUnderscore(loc, pos, c)
 				else
 					return new TokenEmUnderscore(loc, pos, c)

src/parser/nit.sablecc3xx

@@ -91,6 +91,8 @@ extern_code_char
 	;
 extern_code_body = extern_code_char*;
 
+id = lowercase letter*;
+
 /*****************************************************************************/
 States
 /*****************************************************************************/
@@ -203,16 +205,16 @@ at='@';
 semi=';';
 
 classid = uppercase letter*;
-id = lowercase letter*;
+id = id;
 attrid = '_' lowercase letter*;
 
 integer = (number | hex_number | bin_number | oct_number) (('u' prec) | ('i' prec) |);
 float = digit* '.' digit+ | (digit+ | digit* '.' digit+) ('E'|'e') ('+'|'-'|) digit+;
-string = '"' str_body '"' | '"' '"' '"' long_str_body lsend1 | ''' ''' ''' long_sstr_body ''' ''' ''';
-start_string = '"' str_body '{' | '"' '"' '"' long_str_body lsend2;
+string = id? '"' str_body '"' id? | id? '"' '"' '"' long_str_body lsend1 | id? ''' ''' ''' long_sstr_body ''' ''' ''' id?;
+start_string = id? '"' str_body '{' | id? '"' '"' '"' long_str_body lsend2;
 mid_string = '}' str_body '{' | '}' '}' '}' long_str_body lsend2;
-end_string = '}' str_body '"' | '}' '}' '}' long_str_body lsend1;
-char = (''' [[any - '''] - '\'] ''') | (''' '\' any ''');
+end_string = '}' str_body '"' id? | '}' '}' '}' long_str_body lsend1 id? ;
+char = id? ((''' [[any - '''] - '\'] ''') | (''' '\' any ''')) id?;
 bad_string = ('"'|'}') str_body | '"' '"' '"' long_str_body | ''' ''' ''' long_sstr_body;
 bad_char = ''' '\'? any;