Implement String >> #uniq via (new) #uniqueVariableNameFor:

shingarov · May 22, 2024 · cef75f5 · cef75f5
1 parent b318dde
commit cef75f5
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Showing 2 changed files with 17 additions and 1 deletion.
diff --git a/src/SpriteLang/String.extension.st b/src/SpriteLang/String.extension.st
@@ -48,5 +48,5 @@ String >> unifyX: anotherString [
 String >> uniq [
 	"Return new unique variable name suitable for
 	 α-renaming."
-	^self, '__ß', VariableAlphabet nextJ printString
+	^VariableAlphabet uniqueVariableNameFor: self
 ]
diff --git a/src/SpriteLang/VariableAlphabet.extension.st b/src/SpriteLang/VariableAlphabet.extension.st
@@ -0,0 +1,16 @@
+Extension { #name : #VariableAlphabet }
+
+{ #category : #'*SpriteLang' }
+VariableAlphabet class >> uniqueVariableNameFor: original [
+	j isNil ifTrue: [ j:= 0 ].
+	j := j + 1.
+	^String streamContents: [ :s|
+		s nextPutAll: original.
+		s nextPutAll: '__ß'.
+		j printOn: s base: 10 nDigits: 6
+	].
+
+	"
+	VariableAlphabet uniqueVariableNameFor: 'x'
+	"
+]