Improved documentation

docs/Conditions.md

@@ -1,13 +1,33 @@
-## Conditions 
+## Extensions to the base library
+
+This package include some extensions to base classes with the intention of improving readability.
+
+- `Boolean>>#then:` is the equivalent to `ifTrue:`, except that `nil` is not returned if the condition is false.
+- `Boolean>>#then:otherwise:` is the equivalent of `ifTrue:ifFalse:`
+- `BlockClosure>>#unless:` evaluates the block unless the condition is met. It's used to emphasize the block action as the usual case. For example:
+```
+[ html
+    attributeAt: 'x:num'
+    put: (self xnumAmountFormatter format: amount)]
+      unless: amount isUndefined
+```
+- `BlockClosure>>#unless:inWhichCase:` is used when you want to emphasize a positive action, and in the exceptional case that the condition is met, evaluate an exceptional action.
+For example:
+```
+[self createLabelFor: aParameter] unless: aParameter isOptional
+      inWhichCase: [self createOptionalWidgetsFor: aParameter].
+      ```
+
+## Conditions
 
 A condition is used to test a value against it.
 
 ## Arithmetic Conditions
 
-Arithmetic conditions are used to test magnitudes against a provided value. 
+Arithmetic conditions are used to test magnitudes against a provided value.
 
 ```smalltalk
-| condition | 
+| condition |
 condition := ArithmeticCondition toBeEqualTo: 1.
 condition isSatisfiedBy: 1. "returns true"
 condition isSatisfiedBy: 0. "returns false"
@@ -18,7 +38,7 @@ condition isSatisfiedBy: 0. "returns false"
 You can easily build the opposite of a condition sending #negated to it.
 
 ```smalltalk
-| condition | 
+| condition |
 condition := (ArithmeticCondition toBeEqualTo: 1) negated.
 condition isSatisfiedBy: 1. "returns false"
 condition isSatisfiedBy: 0. "returns true"
@@ -30,7 +50,7 @@ You can compose conditions using AND or OR as a logic operator. A simple AND com
 
 ```smalltalk
 | condition |
-condition := (ArithmeticCondition  toBeGreaterThan: 0) 
+condition := (ArithmeticCondition  toBeGreaterThan: 0)
     and: (ArithmeticCondition  toBeLessThan: 2).
 condition isSatisfiedBy: 0. "returns false"
 condition isSatisfiedBy: 1. "returns true"
@@ -40,7 +60,7 @@ A simple OR composition.
 
 ```smalltalk
 | condition |
-condition :=(ArithmeticCondition  toBeEqualTo: 1) 
+condition :=(ArithmeticCondition  toBeEqualTo: 1)
     or: (ArithmeticCondition  toBeEqualTo: 2).
 condition isSatisfiedBy: 1. "returns true"
 condition isSatisfiedBy: 2. "returns true"