Better parser errors on syntax errors. Will show line number, description and where the error happened.

Test function for delimited string if they will break reprising.

4 files changed, 81 insertions, 28 deletions

diff --git a/tikzit/src/common/TikzGraphAssembler.h b/tikzit/src/common/TikzGraphAssembler.h
index adaf443..a0c8a0d 100644
--- a/tikzit/src/common/TikzGraphAssembler.h
+++ b/tikzit/src/common/TikzGraphAssembler.h
@@ -41,6 +41,8 @@
 - (BOOL)parseTikz:(NSString*)tikz;
 - (BOOL)parseTikz:(NSString*)tikz forGraph:(Graph*)gr;
 
+- (BOOL)testTikz:(NSString*)tikz;
+
 - (void)prepareNode;
 - (void)finishNode;
 
diff --git a/tikzit/src/common/TikzGraphAssembler.m b/tikzit/src/common/TikzGraphAssembler.m
index 7d8d0e7..050b5fe 100644
--- a/tikzit/src/common/TikzGraphAssembler.m
+++ b/tikzit/src/common/TikzGraphAssembler.m
@@ -34,8 +34,16 @@ extern int yylex_destroy(void);
 static NSLock *parseLock = nil;
 static id currentAssembler = nil;
 
+int yylineno;
+int yyleng;
+int lineno;
+int tokenpos;
+char *yystr;
+char linebuff[500];
+
+
 void yyerror(const char *str) {
-	NSLog(@"Parse error: %s", str);
+    NSLog(@"Parse error on line %i: %s\n%s\n%@\n", lineno, str, linebuff, [[@"" stringByPaddingToLength:(tokenpos-yyleng) withString: @" " startingAtIndex:0] stringByAppendingString:[@"" stringByPaddingToLength:yyleng withString: @"^" startingAtIndex:0]]);
 	if (currentAssembler != nil) {
         NSError *error = [NSError errorWithDomain:@"net.sourceforge.tikzit"
                                      code:TZ_ERR_PARSE
@@ -81,6 +89,10 @@ int yywrap() {
 
 - (BOOL)parseTikz:(NSString*)tikz forGraph:(Graph*)gr {
 	[parseLock lock];
+    
+    lineno = 1;
+    tokenpos = 0;
+    linebuff[0] = 0;
 	
 	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
 	currentAssembler = self;
@@ -93,12 +105,14 @@ int yywrap() {
 	
 	// the node map keeps track of the mapping of names to nodes
 	nodeMap = [[NSMutableDictionary alloc] init];
-	
-	// do the parsing
-	yy_scan_string([tikz UTF8String]);
-	yyparse();   
-	yylex_destroy();
-	
+    
+	// do the parsing if actual input
+    if([tikz length] > 0){
+        yy_scan_string([tikz UTF8String]);
+        yyparse();
+        yylex_destroy();
+    }
+    
 	[nodeMap release];
 	nodeMap = nil;
 	
@@ -110,6 +124,22 @@ int yywrap() {
 	return (graph != nil);
 }
 
+- (BOOL)testTikz:(NSString *)tikz{
+    BOOL r;
+    
+    NSString * testTikz = [NSString stringWithFormat: @"{%@}", tikz];
+    
+	yy_scan_string([testTikz UTF8String]);
+	yylex();
+    
+    r = !(yyleng < [testTikz length]);
+    
+    [testTikz autorelease];
+	yylex_destroy();
+    
+    return r;
+}
+
 - (void)prepareNode {
 	currentNode = [[Node alloc] init];
 }
diff --git a/tikzit/src/common/tikzlexer.lm b/tikzit/src/common/tikzlexer.lm
index 9af0c8d..8f34ace 100644
--- a/tikzit/src/common/tikzlexer.lm
+++ b/tikzit/src/common/tikzlexer.lm
@@ -1,4 +1,6 @@
 %option nounput
+%option yylineno
+
 %{
 //
 //  tikzparser.l
@@ -30,48 +32,62 @@
 #include "tikzparser.h"
 #endif
 
+extern char linebuff[500];
+extern int lineno;
+extern yy_size_t yyleng;
+extern int tokenpos;
 
 %}
 %%
-\n                             /* ignore end of line */;
-[ \t]+                         /* ignore whitespace */;
-\\begin                        return LATEXBEGIN;
-\\end                          return LATEXEND;
-\{tikzpicture\}                return TIKZPICTURE;
-\{pgfonlayer\}                 return PGFONLAYER;
-\(                             return LEFTPARENTHESIS;
-\)                             return RIGHTPARENTHESIS;		       
-\[                             return LEFTBRACKET;
-\]                             return RIGHTBRACKET;
-;                              return SEMICOLON;
-,                              return COMMA;
-\.                             return FULLSTOP;
-=                              return EQUALS;
-\\draw                         return DRAW;
-to                             return TO;
-\\node                         return NODE;
-\\path                         return PATH;
-node                           return ALTNODE;
-rectangle                      return RECTANGLE;
-at                             return AT;
+%\n                             /* ignore end of line */;
+\n.*    {   strcpy(linebuff, yytext+1);
+            lineno++;
+            tokenpos = 0;
+            yyless(1);
+        }
+[ ]+                           { tokenpos += yyleng; } /* ignore whitespace */;
+[\t]+                          { tokenpos += 4*yyleng; } /* ignore whitespace */;
+\\begin                        { tokenpos += yyleng; return LATEXBEGIN; }
+\\end                          { tokenpos += yyleng; return LATEXEND; }
+\{tikzpicture\}                { tokenpos += yyleng; return TIKZPICTURE; }
+\{pgfonlayer\}                 { tokenpos += yyleng; return PGFONLAYER; }
+\(                             { tokenpos += yyleng; return LEFTPARENTHESIS; }
+\)                             { tokenpos += yyleng; return RIGHTPARENTHESIS; }	       
+\[                             { tokenpos += yyleng; return LEFTBRACKET; }
+\]                             { tokenpos += yyleng; return RIGHTBRACKET; }
+;                              { tokenpos += yyleng; return SEMICOLON; }
+,                              { tokenpos += yyleng; return COMMA; }
+\.                             { tokenpos += yyleng; return FULLSTOP; }
+=                              { tokenpos += yyleng; return EQUALS; }
+\\draw                         { tokenpos += yyleng; return DRAW; }
+to                             { tokenpos += yyleng; return TO; }
+\\node                         { tokenpos += yyleng; return NODE; }
+\\path                         { tokenpos += yyleng; return PATH; }
+node                           { tokenpos += yyleng; return ALTNODE; }
+rectangle                      { tokenpos += yyleng; return RECTANGLE; }
+at                             { tokenpos += yyleng; return AT; }
 
 [0-9]+ {
+    tokenpos += yyleng;
 	yylval.nsstr=[NSString stringWithUTF8String:yytext];
 	return NATURALNUMBER;
 }
 
 (\-?[0-9]*\.[0-9]+)|(\-?[0-9]+) {
+    tokenpos += yyleng;
 	yylval.nsstr=[NSString stringWithUTF8String:yytext];
 	return REALNUMBER;
 }
 
 \\?[a-zA-Z<>\-\'][a-zA-Z<>\-\'0-9]* { //'
+    tokenpos += yyleng;
 	yylval.nsstr=[NSString stringWithUTF8String:yytext];
 	return LWORD;
 }
 
 
 \"[^\"]*\" /* " */ {
+    tokenpos += yyleng;
 	yylval.nsstr=[NSString stringWithUTF8String:yytext];
 	return QUOTEDSTRING;
 }
@@ -93,8 +109,10 @@ at                             return AT;
 	}
 	
 	NSString *s = [buf copy];
+    yyleng += 1 + [buf length];
 	[s autorelease];
 	yylval.nsstr = s;
+    tokenpos += yyleng;
 	return DELIMITEDSTRING;
 }
 
diff --git a/tikzit/src/common/tikzparser.ym b/tikzit/src/common/tikzparser.ym
index 532b6c8..487cfd4 100644
--- a/tikzit/src/common/tikzparser.ym
+++ b/tikzit/src/common/tikzparser.ym
@@ -29,6 +29,9 @@
 #import "TikzGraphAssembler.h"
 #import "GraphElementProperty.h"
 	
+extern char* yystr;
+extern int yylineno;
+extern int tokenpos;
 extern int yylex(void);
 extern void yyerror(const char *str);