add asAccessor

src/Collections-Strings-Tests/SymbolTest.class.st

@@ -285,6 +285,17 @@ SymbolTest >> subCollectionNotIn [
 	^ collectionNotIncluded
 ]
 
+{ #category : 'tests' }
+SymbolTest >> testAsAccessor [
+	self assert: #x: asAccessor equals: #x.
+	"return receiver if it is already a mutator"
+	self assert: #x asAccessor equals: #x.
+	self should: [ self assert: #x:: asAccessor ] raise: Error.	
+	self should: [ self assert: #keyword:selector: asAccessor ] raise: Error.
+	self should: [ self assert: #+ asAccessor ] raise: Error.
+	self should: [ self assert: #'' asAccessor ] raise: Error.	
+]
+
 { #category : 'tests' }
 SymbolTest >> testAsMutator [
 	self assert: #x asMutator equals: #x:.

src/Collections-Strings/Symbol.class.st

@@ -316,6 +316,23 @@ Symbol >> = aSymbol [
 	^ super = aSymbol
 ]
 
+{ #category : 'converting' }
+Symbol >> asAccessor [
+	"Return a accessor (getter) message from a setter message.
+	Return self if it is already a getter."
+
+	"#name asAccessor >>> #name"
+	"#name: asAccessor >>> #name"
+
+	(((self count: [ :char | char = $: ]) > 1) 
+		or: [ self isEmpty 
+		or: [ self isBinary ]]) ifTrue: [ 
+		self error: 'This symbol cannot be converted to an accessor' ].
+
+	self endsWithAColon ifFalse:[ ^ self ].
+	^ (self withoutSuffix: ':') asSymbol
+]
+
 { #category : 'converting' }
 Symbol >> asMutator [
 	"Return a setter message from a getter message.