--- a/MessageNode.st	Tue Aug 16 17:59:13 2005 +0200
+++ b/MessageNode.st	Thu Sep 15 13:29:36 2005 +0200
@@ -349,6 +349,37 @@
 
 !MessageNode methodsFor:'checks'!
 
+checkCondition
+    |args lastArg|
+
+    receiver isBlock ifTrue:[
+        (Block canUnderstand:selector) ifFalse:[
+            ^ 'blocks usually do not respond to ' , selector , ' messages'
+        ].
+    ].
+
+    "/ (rr keyw:ra = a) ifTrue:[ ...]
+
+    receiver isMessage ifTrue:[
+        (receiver numArgs > 0) ifTrue:[
+            (receiver selector isKeyword) ifTrue:[
+                (args := receiver arguments) notEmptyOrNil ifTrue:[
+                    (lastArg := args last) isMessage ifTrue:[
+                        lastArg parenthized ifFalse:[
+                            (#( #'=' #'~=' #'==' #'~~' '>' '<' '>=' '<=') 
+                            includes:(lastArg selector)) ifTrue:[
+                                ^ 'possible precedence error (missing parenthesis) in condition'
+                            ]
+                        ]
+                    ]
+                ]
+            ]
+        ].
+    ].
+
+    ^ nil
+!
+
 checkInlinability
     "early check for possible inlinability"
 
@@ -448,7 +479,7 @@
 !
 
 plausibilityCheck
-    |rec arg1 arg2 arg1Value operand|
+    |rec arg1 arg2 arg1Value operand msg|
 
     (argArray size > 0) ifTrue:[
         arg1 := argArray at:1
@@ -497,11 +528,7 @@
      an error often occuring when you are a beginner ...
     "
     ((selector == #ifTrue:) or:[selector == #ifFalse:]) ifTrue:[
-        receiver isBlock ifTrue:[
-            (Block canUnderstand:selector) ifFalse:[
-                ^ 'blocks usually do not respond to ' , selector , ' messages'
-            ].
-        ].
+        (msg := self checkCondition) notNil ifTrue:[^ msg].
 "/        arg1 isBlock ifFalse:[
 "/            arg1 isConstant ifFalse:[
 "/                ^ 'will fail at runtime, if argument to ' , selector , ' does not evaluate to a block or respond reasonable to #value'
@@ -509,11 +536,7 @@
 "/        ]
     ].
     ((selector == #ifTrue:ifFalse:) or:[selector == #ifFalse:ifTrue:]) ifTrue:[
-        receiver isBlock ifTrue:[
-            (Block canUnderstand:selector) ifFalse:[
-                ^ 'blocks usually do not respond to ' , selector , ' messages'
-            ].
-        ].
+        (msg := self checkCondition) notNil ifTrue:[^ msg].
 "/        arg1 isBlock ifFalse:[
 "/            arg1 isConstant ifFalse:[
 "/                ^ 'will fail at runtime, if 1st. argument to ' , selector , ' does not evaluate to a block or respond reasonable to #value'
@@ -2914,5 +2937,5 @@
 !MessageNode class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libcomp/MessageNode.st,v 1.144 2005-04-20 14:40:39 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libcomp/MessageNode.st,v 1.145 2005-09-15 11:29:36 cg Exp $'
 ! !