Make the parser/lexer reentrant

No more locking!  Also, the interface for TikzGraphAssembler is much
simpler.

Changes to OSX code are completely untested.

17 files changed, 246 insertions, 262 deletions

diff --git a/tikzit/.gitignore b/tikzit/.gitignore
index 6802e27..644b16b 100644
--- a/tikzit/.gitignore
+++ b/tikzit/.gitignore
@@ -17,6 +17,7 @@ Makefile.in
 /missing
 /src/tikzit
 /src/tikzit.res
+/src/common/tikzlexer.h
 /src/common/tikzlexer.m
 /src/common/tikzparser.m
 /src/common/tikzparser.h
diff --git a/tikzit/src/Makefile.am b/tikzit/src/Makefile.am
index 6ffaa26..e869686 100644
--- a/tikzit/src/Makefile.am
+++ b/tikzit/src/Makefile.am
@@ -127,7 +127,7 @@ common/tikzlexer.m: common/tikzlexer.lm
 	$(AM_V_GEN)$(LEX) -o $@ $^
 
 common/tikzparser.m: common/tikzparser.ym
-	$(AM_V_GEN)$(YACC) --defines=common/tikzparser.h --output=$@ $^
+	$(AM_V_GEN)$(YACC) --output=$@ $^
 
 common/tikzparser.h: common/tikzparser.m
 
diff --git a/tikzit/src/common/TikzGraphAssembler+Parser.h b/tikzit/src/common/TikzGraphAssembler+Parser.h
index 683e3e2..efceae9 100644
--- a/tikzit/src/common/TikzGraphAssembler+Parser.h
+++ b/tikzit/src/common/TikzGraphAssembler+Parser.h
@@ -25,9 +25,19 @@
 #import "TikzGraphAssembler.h"
 
 @interface TikzGraphAssembler (Parser)
+- (Graph*) graph;
 /** Store a node so that it can be looked up by name later */
-- (void)addNodeToMap:(Node*)n;
-- (Node*)nodeWithName:(NSString*)name;
+- (void) addNodeToMap:(Node*)n;
+/** Get a previously-stored node by name */
+- (Node*) nodeWithName:(NSString*)name;
+- (void) newLineStarted:(char *)text;
+- (void) incrementPosBy:(size_t)amount;
+- (void) invalidateWithError:(const char *)message;
+- (void*) scanner;
 @end
 
+#define YY_EXTRA_TYPE TikzGraphAssembler *
+#define YYLEX_PARAM [assembler scanner]
+void yyerror(TikzGraphAssembler *assembler, const char *str);
+
 // vi:ft=objc:noet:ts=4:sts=4:sw=4
diff --git a/tikzit/src/common/TikzGraphAssembler.h b/tikzit/src/common/TikzGraphAssembler.h
index 3fc4e9e..16fdf7f 100644
--- a/tikzit/src/common/TikzGraphAssembler.h
+++ b/tikzit/src/common/TikzGraphAssembler.h
@@ -26,24 +26,19 @@
 
 @interface TikzGraphAssembler : NSObject {
 	Graph *graph;
+	void *scanner;
 	NSMutableDictionary *nodeMap;
 	NSError *lastError;
+	char linebuff[500];
+	int lineno;
+	size_t tokenpos;
 }
 
-@property (readonly) Graph *graph;
-@property (readonly) NSError *lastError;
-
-- (BOOL)parseTikz:(NSString*)tikz;
-- (BOOL)parseTikz:(NSString*)tikz forGraph:(Graph*)gr;
-
-- (BOOL)testTikz:(NSString*)tikz;
-
-- (void)invalidate;
-- (void)invalidateWithError:(NSError*)error;
-
-+ (void)setup;
-+ (TikzGraphAssembler*)currentAssembler;
-+ (TikzGraphAssembler*)assembler;
++ (BOOL) parseTikz:(NSString*)tikz forGraph:(Graph*)gr error:(NSError**)e;
++ (BOOL) parseTikz:(NSString*)tikz forGraph:(Graph*)gr;
++ (Graph*) parseTikz:(NSString*)tikz error:(NSError**)e;
++ (Graph*) parseTikz:(NSString*)tikz;
++ (BOOL)validateTikzPropertyNameOrValue:(NSString*)tikz;
 
 @end
 
diff --git a/tikzit/src/common/TikzGraphAssembler.m b/tikzit/src/common/TikzGraphAssembler.m
index 26bf515..5a01036 100644
--- a/tikzit/src/common/TikzGraphAssembler.m
+++ b/tikzit/src/common/TikzGraphAssembler.m
@@ -22,84 +22,72 @@
 //  
 
 #import "TikzGraphAssembler.h"
+#import "TikzGraphAssembler+Parser.h"
+#import "tikzparser.h"
+#import "tikzlexer.h"
 #import "NSError+Tikzit.h"
 
-extern int yyparse(void);
-extern int yylex(void);  
-extern int yy_scan_string(const char* yy_str);
-extern void yy_delete_buffer(int b);
-extern int yylex_destroy(void);
-
-
-static NSLock *parseLock = nil;
-static id currentAssembler = nil;
-
-extern int yylineno;
-extern int yyleng;
-int lineno;
-int tokenpos;
-extern char *yystr;
-char linebuff[500];
-
-
-void yyerror(const char *str) {
-    // if the error is on the first line, treat specially
-    if(lineno == 1){
-//        strcpy(linebuff, yytext+1);
-        NSLog(@"Problem ahoy!");
-    }
-    
-    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
-                                         userInfo:[NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:[NSString stringWithCString:str encoding:NSUTF8StringEncoding],
-                                                                                       [NSNumber numberWithInt:lineno],
-                                                                                       [NSString stringWithCString:linebuff encoding:NSUTF8StringEncoding],
-                                                                                       [NSNumber numberWithInt:tokenpos],
-                                                                                       [NSNumber numberWithInt:yyleng],
-                                                                                       nil]
-                                                                              forKeys: [NSArray arrayWithObjects:NSLocalizedDescriptionKey,
-                                                                                        @"lineNumber",
-                                                                                        @"syntaxString",
-                                                                                        @"tokenStart",
-                                                                                        @"tokenLength",
-                                                                                        nil]]];
-        
-		[currentAssembler invalidateWithError:error];
-	}
-}
-
-int yywrap() {
-	return 1;
+void yyerror(TikzGraphAssembler *assembler, const char *str) {
+	[assembler invalidateWithError:str];
 }
 
 @implementation TikzGraphAssembler
 
 - (id)init {
+	self = nil;
+	return nil;
+}
+
+- (id)initWithGraph:(Graph*)g {
 	self = [super init];
+	if (self) {
+		graph = [g retain];
+		nodeMap = [[NSMutableDictionary alloc] init];
+		yylex_init (&scanner);
+		yyset_extra(self, scanner);
+	}
 	return self;
 }
 
 - (void)dealloc {
 	[graph release];
+	[nodeMap release];
 	[lastError release];
+	yylex_destroy (scanner);
 	[super dealloc];
 }
 
-- (Graph*)graph { return graph; }
-- (NSError*)lastError { return lastError; }
-
-- (BOOL)parseTikz:(NSString *)tikz {
-	return [self parseTikz:tikz forGraph:[Graph graph]];
++ (BOOL) parseTikz:(NSString*)tikz forGraph:(Graph*)gr {
+	return [self parseTikz:tikz forGraph:gr error:NULL];
+}
++ (Graph*) parseTikz:(NSString*)tikz error:(NSError**)e {
+	Graph *gr = [[Graph alloc] init];
+	if ([self parseTikz:tikz forGraph:gr error:e]) {
+		return [gr autorelease];
+	} else {
+		[gr release];
+		return nil;
+	}
+}
++ (Graph*) parseTikz:(NSString*)tikz {
+	return [self parseTikz:tikz error:NULL];
 }
 
-- (BOOL)parseTikz:(NSString*)tikz forGraph:(Graph*)gr {
-	[parseLock lock];
-    
-    lineno = 1;
-    tokenpos = 0;
-    NSRange range = [tikz rangeOfString:@"\n"];
++ (BOOL) parseTikz:(NSString*)tikz forGraph:(Graph*)gr error:(NSError**)error {
+
+	if([tikz length] == 0) {
+		// empty string -> empty graph
+		return YES;
+	}
+
+	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+	TikzGraphAssembler *assembler = [[self alloc] initWithGraph:gr];
+	[assembler autorelease];
+
+	/*
+	lineno = 1;
+	tokenpos = 0;
+	NSRange range = [tikz rangeOfString:@"\n"];
 	NSString *firstLine;
 	if (range.length == 0) {
 		firstLine = tikz;
@@ -112,49 +100,50 @@ int yywrap() {
 		// first line too long; just terminate it at the end of the buffer
 		linebuff[499] = 0;
 	}
+	*/
 	
-	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
-	currentAssembler = self;
-	
-	// set the current graph
-	if (graph != gr) {
-		[graph release];
-		graph = [gr retain];
-	}
-	
-	// the node map keeps track of the mapping of names to nodes
-	nodeMap = [[NSMutableDictionary alloc] init];
-    
-	// do the parsing if actual input
-    if([tikz length] > 0){
-        yy_scan_string([tikz UTF8String]);
-        yyparse();
-        yylex_destroy();
-    }
-    
-	[nodeMap release];
-	nodeMap = nil;
+	yy_scan_string([tikz UTF8String], [assembler scanner]);
+	int result = yyparse(assembler);
 	
-	currentAssembler = nil;
 	[pool drain];
-	
-	[parseLock unlock];
-	
-	return (graph != nil);
+	if (result == 0) {
+		return YES;
+	} else {
+		if (error) {
+			/*
+			if (lastError) {
+				*error = [[lastError retain] autorelease];
+			} else
+			*/
+			if (result == 1) {
+				*error = [NSError errorWithMessage:@"Syntax error"
+											  code:TZ_ERR_PARSE];
+			} else if (result == 2) {
+				*error = [NSError errorWithMessage:@"Insufficient memory"
+											  code:TZ_ERR_PARSE];
+			} else {
+				*error = [NSError errorWithMessage:@"Unknown error"
+											  code:TZ_ERR_PARSE];
+			}
+		}
+		return NO;
+	}
 }
 
-- (BOOL)testTikz:(NSString *)tikz{
++ (BOOL)validateTikzPropertyNameOrValue:(NSString*)tikz {
     BOOL r;
     
     NSString * testTikz = [NSString stringWithFormat: @"{%@}", tikz];
     
-	yy_scan_string([testTikz UTF8String]);
-	yylex();
-    
-    r = !(yyleng < [testTikz length]);
-    
+	void *scanner;
+	yylex_init (&scanner);
+	yyset_extra(nil, scanner);
+	yy_scan_string([testTikz UTF8String], scanner);
+	YYSTYPE lval;
+	yylex(&lval, scanner);
+    r = !(yyget_leng(scanner) < [testTikz length]);
+	yylex_destroy(scanner);
     [testTikz autorelease];
-	yylex_destroy();
     
     return r;
 }
@@ -165,32 +154,66 @@ int yywrap() {
 	lastError = nil;
 }
 
-- (void)invalidateWithError:(NSError*)error {
-	[self invalidate];
-	lastError = [error retain];
-}
-
-+ (void)setup {
-	parseLock = [[NSLock alloc] init];
-}
-
-+ (TikzGraphAssembler*)currentAssembler {
-	return currentAssembler;
-}
-
-+ (TikzGraphAssembler*)assembler {
-	return [[[TikzGraphAssembler alloc] init] autorelease];
-}
-
 @end
 
 @implementation TikzGraphAssembler (Parser)
+- (Graph*)graph { return graph; }
 - (void)addNodeToMap:(Node*)n {
 	[nodeMap setObject:n forKey:[n name]];
 }
 - (Node*)nodeWithName:(NSString*)name {
-    return [nodeMap objectForKey:name];
+	return [nodeMap objectForKey:name];
+}
+- (void) newLineStarted:(char *)text {
+	/*
+	strncpy(linebuff, yytext+1, 500);
+	linebuff[499] = 0; // ensure null-terminated
+	lineno++;
+	tokenpos = 0;
+	*/
+}
+- (void) incrementPosBy:(size_t)amount {
+	//tokenpos += amount;
+}
+
+- (void) invalidateWithError:(const char *)message {
+	/*
+	// if the error is on the first line, treat specially
+	if([assembler lineNumber] == 1){
+		//strcpy(linebuff, yytext+1);
+		NSLog(@"Problem ahoy!");
+	}
+	
+	NSString *pointerStrPad = [@"" stringByPaddingToLength:(tokenpos-yyleng)
+												withString:@" "
+										   startingAtIndex:0];
+	NSString *pointerStr = [@"" stringByPaddingToLength:yyleng
+											 withString:@"^"
+										startingAtIndex:0];
+	NSLog(@"Parse error on line %i: %s\n%s\n%@\n", lineno, str, linebuff,
+			[pointerStrPad stringByAppendingString:pointerStr]);
+	NSDictionary *userInfo =
+		[NSDictionary dictionaryWithObjectsAndKeys:
+			[NSString stringWithUTF8String:str],
+				NSLocalizedDescriptionKey,
+			[NSNumber numberWithInt:lineno],
+				@"lineNumber",
+			[NSString stringWithUTF8String:linebuff],
+				@"syntaxString",
+			[NSNumber numberWithInt:tokenpos],
+				@"tokenStart",
+			[NSNumber numberWithInt:yyleng],
+				@"tokenLength"];
+	NSError *error =
+		[NSError errorWithDomain:@"net.sourceforge.tikzit"
+							code:TZ_ERR_PARSE
+						userInfo:userInfo];
+	
+	lastError = [error retain];
+						*/
+	[self invalidate];
 }
+- (void*) scanner { return scanner; }
 @end
 
 // vi:ft=objc:ts=4:noet:sts=4:sw=4
diff --git a/tikzit/src/common/TikzShape.m b/tikzit/src/common/TikzShape.m
index b5b23c3..722275c 100644
--- a/tikzit/src/common/TikzShape.m
+++ b/tikzit/src/common/TikzShape.m
@@ -35,11 +35,7 @@
 												  error:NULL];
 	if (tikz == nil) return nil;
 	
-	TikzGraphAssembler *ass = [[TikzGraphAssembler alloc] init];
-	[ass parseTikz:tikz];
-	
-	Graph *graph = [ass graph];
-    [ass release];
+	Graph *graph = [TikzGraphAssembler parseTikz:tikz];
 	if (graph == nil) return nil;
 	
 	NSRect graphBounds = ([graph hasBoundingBox]) ? [graph boundingBox] : [graph bounds];
diff --git a/tikzit/src/common/tikzlexer.lm b/tikzit/src/common/tikzlexer.lm
index ad99445..3e2e0ed 100644
--- a/tikzit/src/common/tikzlexer.lm
+++ b/tikzit/src/common/tikzlexer.lm
@@ -1,11 +1,3 @@
-%option nounput
-%option yylineno
-%s props
-%s xcoord
-%s ycoord
-%s noderef
-FLOAT \-?[0-9]*(\.[0-9]+)?
-
 %{
 /*
  * Copyright 2010       Chris Heunen
@@ -28,96 +20,100 @@ FLOAT \-?[0-9]*(\.[0-9]+)?
  */
 
 #import <Foundation/Foundation.h>
-#ifdef __APPLE__
-#include "y.tab.h"
-#else
-#include "tikzparser.h"
-#endif
-
-extern char linebuff[500];
-extern int lineno;
-extern int tokenpos;
+#import "tikzparser.h"
 
 %}
+
+%option reentrant bison-bridge 8bit
+%option nounput
+%option yylineno
+%option noyywrap
+%option header-file="common/tikzlexer.h"
+
+%s props
+%s xcoord
+%s ycoord
+%s noderef
+
+FLOAT \-?[0-9]*(\.[0-9]+)?
+
 %%
-%\n                             /* ignore end of line */;
-\n.*    {   strncpy(linebuff, yytext+1, 500);
-			linebuff[499] = 0; // ensure null-terminated
-            lineno++;
-            tokenpos = 0;
-            yyless(1);
-        }
-<INITIAL,xcoord,ycoord,props,noderef>[ ]+  { tokenpos += yyleng; } /* ignore whitespace */;
-<INITIAL,xcoord,ycoord,props,noderef>[\t]+ { tokenpos += 8*yyleng; } /* ignore whitespace */;
-\\begin\{tikzpicture\}         { tokenpos += yyleng; return BEGIN_TIKZPICTURE_CMD; }
-\\end\{tikzpicture\}           { tokenpos += yyleng; return END_TIKZPICTURE_CMD; }
-\\begin\{pgfonlayer\}          { tokenpos += yyleng; return BEGIN_PGFONLAYER_CMD; }
-\\end\{pgfonlayer\}            { tokenpos += yyleng; return END_PGFONLAYER_CMD; }
-\\draw                         { tokenpos += yyleng; return DRAW_CMD; }
-\\node                         { tokenpos += yyleng; return NODE_CMD; }
-\\path                         { tokenpos += yyleng; return PATH_CMD; }
-rectangle                      { tokenpos += yyleng; return RECTANGLE; }
-node                           { tokenpos += yyleng; return NODE; }
-at                             { tokenpos += yyleng; return AT; }
-to                             { tokenpos += yyleng; return TO; }
-;                              { tokenpos += yyleng; return SEMICOLON; }
+
+\n.* {
+	[yyextra newLineStarted:yytext+1];
+	yyless(1);
+}
+<INITIAL,xcoord,ycoord,props,noderef>[ ]+  { [yyextra incrementPosBy:yyleng]; } /* ignore whitespace */;
+<INITIAL,xcoord,ycoord,props,noderef>[\t]+ { [yyextra incrementPosBy:8*yyleng]; } /* ignore whitespace */;
+\\begin\{tikzpicture\}         { [yyextra incrementPosBy:yyleng]; return BEGIN_TIKZPICTURE_CMD; }
+\\end\{tikzpicture\}           { [yyextra incrementPosBy:yyleng]; return END_TIKZPICTURE_CMD; }
+\\begin\{pgfonlayer\}          { [yyextra incrementPosBy:yyleng]; return BEGIN_PGFONLAYER_CMD; }
+\\end\{pgfonlayer\}            { [yyextra incrementPosBy:yyleng]; return END_PGFONLAYER_CMD; }
+\\draw                         { [yyextra incrementPosBy:yyleng]; return DRAW_CMD; }
+\\node                         { [yyextra incrementPosBy:yyleng]; return NODE_CMD; }
+\\path                         { [yyextra incrementPosBy:yyleng]; return PATH_CMD; }
+rectangle                      { [yyextra incrementPosBy:yyleng]; return RECTANGLE; }
+node                           { [yyextra incrementPosBy:yyleng]; return NODE; }
+at                             { [yyextra incrementPosBy:yyleng]; return AT; }
+to                             { [yyextra incrementPosBy:yyleng]; return TO; }
+;                              { [yyextra incrementPosBy:yyleng]; return SEMICOLON; }
 
 \([ ]*{FLOAT}[ ]*,[ ]*{FLOAT}[ ]*\) {
-	tokenpos += 1;
+	[yyextra incrementPosBy:1];
 	yyless(1);
 	BEGIN(xcoord);
 }
 <xcoord>{FLOAT} {
-	tokenpos += yyleng;
-	yylval.pt.x=(float)strtod(yytext,NULL);
+	[yyextra incrementPosBy:yyleng];
+	yylval->pt.x=(float)strtod(yytext,NULL);
 	BEGIN(ycoord);
 }
-<ycoord>, { tokenpos += yyleng; }
+<ycoord>, { [yyextra incrementPosBy:yyleng]; }
 <ycoord>{FLOAT} {
-	tokenpos += yyleng;
-	yylval.pt.y=(float)strtod(yytext,NULL);
+	[yyextra incrementPosBy:yyleng];
+	yylval->pt.y=(float)strtod(yytext,NULL);
 }
 <ycoord>\) {
-	tokenpos += yyleng;
+	[yyextra incrementPosBy:yyleng];
 	BEGIN(INITIAL);
 	return COORD;
 }
 
  /* when we see "[", change parsing mode */
 \[ /*syntaxhlfix]*/ {
-	tokenpos += yyleng;
+	[yyextra incrementPosBy:yyleng];
 	BEGIN(props);
 	return LEFTBRACKET;
 }
-<props>= { tokenpos += yyleng; return EQUALS; }
-<props>, { tokenpos += yyleng; return COMMA; }
+<props>= { [yyextra incrementPosBy:yyleng]; return EQUALS; }
+<props>, { [yyextra incrementPosBy:yyleng]; return COMMA; }
 <props>[^=,\{\] \t]([^=,\{\]]*[^=,\{\] \t])? {
-	tokenpos += yyleng;
-	yylval.nsstr=[NSString stringWithUTF8String:yytext];
+	[yyextra incrementPosBy:yyleng];
+	yylval->nsstr=[NSString stringWithUTF8String:yytext];
 	return PROPSTRING;
 }
 <props>\] {
-	tokenpos += yyleng;
+	[yyextra incrementPosBy:yyleng];
 	BEGIN(INITIAL);
 	return RIGHTBRACKET;
 }
 
 \( {
-	tokenpos += yyleng;
+	[yyextra incrementPosBy:yyleng];
 	BEGIN(noderef);
 	return LEFTPARENTHESIS;
 }
 <noderef>\. {
-	tokenpos += yyleng;
+	[yyextra incrementPosBy:yyleng];
 	return FULLSTOP;
 }
 <noderef>[^\.\{\)]+ {
-	tokenpos += yyleng;
-	yylval.nsstr=[NSString stringWithUTF8String:yytext];
+	[yyextra incrementPosBy:yyleng];
+	yylval->nsstr=[NSString stringWithUTF8String:yytext];
 	return REFSTRING;
 }
 <noderef>\) {
-	tokenpos += yyleng;
+	[yyextra incrementPosBy:yyleng];
 	BEGIN(INITIAL);
 	return RIGHTPARENTHESIS;
 }
@@ -127,7 +123,7 @@ to                             { tokenpos += yyleng; return TO; }
 	unsigned int brace_depth = 1;
 	unsigned int escape = 0;
 	while (1) {
-		char c = input();
+		char c = input(yyscanner);
 		// eof reached before closing brace
 		if (c == '\0' || c == EOF) yyterminate();
 
@@ -147,8 +143,8 @@ to                             { tokenpos += yyleng; return TO; }
 	NSString *s = [buf copy];
     yyleng += 1 + [buf length];
 	[s autorelease];
-	yylval.nsstr = s;
-    tokenpos += yyleng;
+	yylval->nsstr = s;
+    [yyextra incrementPosBy:yyleng];
 	return DELIMITEDSTRING;
 }
 
diff --git a/tikzit/src/common/tikzparser.ym b/tikzit/src/common/tikzparser.ym
index 074ec2d..1183f12 100644
--- a/tikzit/src/common/tikzparser.ym
+++ b/tikzit/src/common/tikzparser.ym
@@ -1,5 +1,3 @@
-%error-verbose
-
 %{
 /*
  * Copyright 2010       Chris Heunen
@@ -21,18 +19,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#import "TikzGraphAssembler+Parser.h"
 #import "Edge.h"
 
-extern char* yystr;
-extern int yylineno;
-extern int tokenpos;
-extern int yylex(void);
-extern void yyerror(const char *str);
-
 %}
 
 %code requires {
+#import "TikzGraphAssembler+Parser.h"
 #import "GraphElementData.h"
 #import "GraphElementProperty.h"
 #import "Node.h"
@@ -42,6 +34,12 @@ struct noderef {
 };
 }
 
+%defines "common/tikzparser.h"
+%pure-parser
+%parse-param {TikzGraphAssembler *assembler}
+%error-verbose
+
+
 %union {
 	NSPoint pt;
 	NSString *nsstr;
@@ -51,6 +49,10 @@ struct noderef {
 	struct noderef noderef;
 };
 
+%{
+#import "tikzlexer.h"
+%}
+
 
 %token BEGIN_TIKZPICTURE_CMD "\\begin{tikzpicture}"
 %token END_TIKZPICTURE_CMD "\\end{tikzpicture}"
@@ -127,14 +129,14 @@ node: "\\node" optproperties nodename "at" COORD DELIMITEDSTRING ";"
 		[node setName:$3];
 		[node setPoint:$5];
 		[node setLabel:$6];
-		[[TikzGraphAssembler currentAssembler] addNodeToMap:node];
-		[[[TikzGraphAssembler currentAssembler] graph] addNode:node];
+		[assembler addNodeToMap:node];
+		[[assembler graph] addNode:node];
 	};
 
 optanchor:  { $$ = nil; } | "." REFSTRING { $$ = $2; };
 noderef: "(" REFSTRING optanchor ")"
 	{
-		$$.node = [[TikzGraphAssembler currentAssembler] nodeWithName:$2];
+		$$.node = [assembler nodeWithName:$2];
 		$$.anchor = $3;
 	};
 optnoderef:
@@ -163,7 +165,7 @@ edge: "\\draw" optproperties noderef "to" optedgenode optnoderef ";"
 			[edge setTargetAnchor:$3.anchor];
 		}
 		[edge setAttributesFromData];
-		[[[TikzGraphAssembler currentAssembler] graph] addEdge:edge];
+		[[assembler graph] addEdge:edge];
 	};
 
 ignoreprop: val | val "=" val;
@@ -172,7 +174,7 @@ optignoreprops: "[" ignoreprops "]";
 boundingbox:
 	"\\path" optignoreprops COORD "rectangle" COORD ";"
 	{
-		[[[TikzGraphAssembler currentAssembler] graph] setBoundingBox:NSRectAroundPoints($3, $5)];
+		[[assembler graph] setBoundingBox:NSRectAroundPoints($3, $5)];
 	};
 
 /* vi:ft=yacc:noet:ts=4:sts=4:sw=4
diff --git a/tikzit/src/gtk/TikzDocument.h b/tikzit/src/gtk/TikzDocument.h
index da73fac..2b55f05 100644
--- a/tikzit/src/gtk/TikzDocument.h
+++ b/tikzit/src/gtk/TikzDocument.h
@@ -70,7 +70,6 @@
 @property (readonly) NSString *undoName;
 @property (readonly) NSString *redoName;
 
-- (BOOL) validateTikz:(NSString**)tikz error:(NSError**)error;
 - (BOOL) updateTikz:(NSString*)t error:(NSError**)error;
 
 - (Graph*) cutSelection;
diff --git a/tikzit/src/gtk/TikzDocument.m b/tikzit/src/gtk/TikzDocument.m
index 30d604a..78746f2 100644
--- a/tikzit/src/gtk/TikzDocument.m
+++ b/tikzit/src/gtk/TikzDocument.m
@@ -256,26 +256,6 @@
     return tikz;
 }
 
-- (BOOL) validateTikz:(NSString**)t error:(NSError**)error {
-    if (*t == nil) {
-        return NO;
-    }
-    if (*t == tikz || [*t isEqual:tikz]) {
-        return YES;
-    }
-
-    TikzGraphAssembler *a = [TikzGraphAssembler assembler];
-    BOOL success = [a parseTikz:*t];
-    if (!success && error != NULL) {
-        *error = [a lastError];
-        if (*error == nil) {
-            *error = [NSError errorWithMessage:@"Unknown error"
-                                          code:TZ_ERR_PARSE];
-        }
-    }
-    return success;
-}
-
 - (BOOL) updateTikz:(NSString*)t error:(NSError**)error {
     if (t == nil) {
         t = [NSString string];
@@ -284,25 +264,17 @@
         return YES;
     }
 
-    TikzGraphAssembler *a = [TikzGraphAssembler assembler];
-    BOOL success = [a parseTikz:t];
-    if (success) {
+    Graph *g = [TikzGraphAssembler parseTikz:t error:error];
+    if (g) {
         // updateTikz actually generates a graph from the tikz,
         // and generates the final tikz from that
         [self startUndoGroup];
-        [self setGraph:[a graph]];
+        [self setGraph:g];
         [self nameAndEndUndoGroup:@"Update tikz"];
-    } else {
-        if (error != NULL) {
-            *error = [a lastError];
-            if (*error == nil) {
-                *error = [NSError errorWithMessage:@"Unknown error"
-                                              code:TZ_ERR_PARSE];
-            }
-        }
+        return YES;
     }
 
-    return success;
+    return NO;
 }
 
 - (Graph*) cutSelection {
@@ -338,9 +310,8 @@
 }
 
 - (void) pasteFromTikz:(NSString*)t {
-    TikzGraphAssembler *a = [TikzGraphAssembler assembler];
-    if ([a parseTikz:t]) {
-        Graph *clipboard = [a graph];
+    Graph *clipboard = [TikzGraphAssembler parseTikz:t];
+    if (clipboard) {
         [self attachStylesToGraph:clipboard];
         [self paste:clipboard];
     }
diff --git a/tikzit/src/gtk/main.m b/tikzit/src/gtk/main.m
index eb06449..10fa990 100644
--- a/tikzit/src/gtk/main.m
+++ b/tikzit/src/gtk/main.m
@@ -81,7 +81,6 @@ int main (int argc, char *argv[]) {
 
     tz_register_stock_items();
     clipboard_init();
-    [TikzGraphAssembler setup];
 
     Application *app = nil;
     if (argc > 1) {
diff --git a/tikzit/src/osx/AppDelegate.m b/tikzit/src/osx/AppDelegate.m
index 87d3ae0..affb95c 100644
--- a/tikzit/src/osx/AppDelegate.m
+++ b/tikzit/src/osx/AppDelegate.m
@@ -22,7 +22,6 @@
 //  
 
 #import "AppDelegate.h"
-#import "TikzGraphAssembler.h"
 #import "TikzDocument.h"
 #import "Shape.h"
 #import "SupportDir.h"
@@ -36,8 +35,6 @@
 }
 
 - (void)awakeFromNib {
-	[TikzGraphAssembler setup]; // initialise lex/yacc parser globals
-	
 	[SupportDir createUserSupportDir];
 	NSString *supportDir = [SupportDir userSupportDir];
 	//NSLog(stylePlist);
diff --git a/tikzit/src/osx/Graph+Coder.m b/tikzit/src/osx/Graph+Coder.m
index 6a3f650..7d3787e 100644
--- a/tikzit/src/osx/Graph+Coder.m
+++ b/tikzit/src/osx/Graph+Coder.m
@@ -13,8 +13,7 @@
 
 - (id)initWithCoder:(NSCoder*)coder {
 	NSString *tikz = [coder decodeObject];
-	TikzGraphAssembler *ass = [[TikzGraphAssembler alloc] init];
-	[ass parseTikz:tikz forGraph:self];
+        [TikzGraphAssembler parseTikz:tikz forGraph:self];
 	return self;
 }
 
diff --git a/tikzit/src/osx/GraphicsView.m b/tikzit/src/osx/GraphicsView.m
index d5d6186..49b1af6 100644
--- a/tikzit/src/osx/GraphicsView.m
+++ b/tikzit/src/osx/GraphicsView.m
@@ -1099,11 +1099,9 @@ static CGColorRef cgGrayColor, cgWhiteColor, cgClearColor = nil;
 		NSData *data = [cb dataForType:type];
 		NSString *tikz = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
         //NSLog(@"pasting tikz:\n%@",tikz);
-		TikzGraphAssembler *ass = [[TikzGraphAssembler alloc] init];
-		if ([ass parseTikz:tikz]) {
+		Graph *clip = [TikzGraphAssembler parseTikz:tikz];
+		if (clip) {
             //NSLog(@"tikz pasted:\n%@",tikz);
-			Graph *clip = [ass graph];
-			
 			NSRect graphBounds = [graph bounds];
 			NSRect clipBounds = [clip bounds];
 			float dx = graphBounds.origin.x +
diff --git a/tikzit/src/osx/TikzFormatter.m b/tikzit/src/osx/TikzFormatter.m
index ecbb0bc..8972706 100644
--- a/tikzit/src/osx/TikzFormatter.m
+++ b/tikzit/src/osx/TikzFormatter.m
@@ -38,8 +38,7 @@
 - (BOOL)getObjectValue:(out id *)obj forString:(NSString *)string errorDescription:(out NSString **)error{    
     *obj = [NSString stringWithString:string];
     
-    TikzGraphAssembler *ass = [[TikzGraphAssembler alloc] init];
-	BOOL r = [ass testTikz:string];
+	BOOL r = [TikzGraphAssembler validateTikzPropertyNameOrValue:string];
     
     if (!r && error)
         *error = NSLocalizedString(@"Invalid input, couldn't parse value.", @"tikz user input error");
diff --git a/tikzit/src/osx/TikzSourceController.h b/tikzit/src/osx/TikzSourceController.h
index c829336..3408d9f 100644
--- a/tikzit/src/osx/TikzSourceController.h
+++ b/tikzit/src/osx/TikzSourceController.h
@@ -24,7 +24,6 @@
 #import <Cocoa/Cocoa.h>
 
 #import "GraphicsView.h"
-#import "TikzGraphAssembler.h"
 #import "ParseErrorView.h"
 
 @interface TikzSourceController : NSObject {
@@ -43,7 +42,7 @@
 	BOOL tikzChanged;
 	BOOL justUndid;
 	
-	TikzGraphAssembler *assembler;
+	NSError *lastError;
 }
 
 @property BOOL tikzChanged;
diff --git a/tikzit/src/osx/TikzSourceController.m b/tikzit/src/osx/TikzSourceController.m
index d05aa41..d01589b 100644
--- a/tikzit/src/osx/TikzSourceController.m
+++ b/tikzit/src/osx/TikzSourceController.m
@@ -22,6 +22,7 @@
 //  
 
 #import "TikzSourceController.h"
+#import "TikzGraphAssembler.h"
 #import "Graph.h"
 
 @implementation TikzSourceController
@@ -82,8 +83,6 @@
 
 - (void)awakeFromNib {
 	justUndid = NO;
-	assembler = [[TikzGraphAssembler alloc] init];
-	
 	successColor = [NSColor colorWithCalibratedRed:0.0f
 											 green:0.5f
 											  blue:0.0f
@@ -143,11 +142,12 @@
 }
 
 - (BOOL)tryParseTikz {
-    BOOL success = [assembler parseTikz:[self tikz]];
+    Graph *g = [TikzGraphAssembler parseTikz:[self tikz]
+                                       error:&lastError];
     
-    if (success) {
+    if (g) {
         [graphicsView deselectAll:self];
-        [graphicsView setGraph:[assembler graph]];
+        [graphicsView setGraph:g];
         [graphicsView refreshLayers];
         [self doRevertTikz];
     }
@@ -181,7 +181,7 @@
             [status setStringValue:@"parse error"];
             [status setTextColor:failedColor];
             
-            NSDictionary *d = [[assembler lastError] userInfo];
+            NSDictionary *d = [lastError userInfo];
             
             NSString *ts = [NSString stringWithFormat: @"Parse error on line %@: %@\n", [d valueForKey:@"lineNumber"], [d valueForKey:NSLocalizedDescriptionKey]];
             NSMutableAttributedString *as = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat: @"Parse error on line %@: %@\n%@\n", [d valueForKey:@"lineNumber"], [d valueForKey:NSLocalizedDescriptionKey], [[d valueForKey:@"syntaxString"] stringByReplacingOccurrencesOfString:@"\t" withString:@""]]];