diff options
Diffstat (limited to 'smalltalk.html.markdown')
| -rw-r--r-- | smalltalk.html.markdown | 96 |
1 files changed, 48 insertions, 48 deletions
diff --git a/smalltalk.html.markdown b/smalltalk.html.markdown index a434a1ad..2c17b753 100644 --- a/smalltalk.html.markdown +++ b/smalltalk.html.markdown @@ -11,33 +11,33 @@ contributors: Feedback highly appreciated! Reach me at [@jigyasa_grover](https://twitter.com/jigyasa_grover) or send me an e-mail at `grover.jigyasa1@gmail.com`. -##Allowable characters: -- a-z -- A-Z -- 0-9 +##Allowable characters: +- a-z +- A-Z +- 0-9 - .+/\*~<>@%|&? - blank, tab, cr, ff, lf ##Variables: -- variables must be declared before use -- shared vars must begin with uppercase -- local vars must begin with lowercase +- variables must be declared before use +- shared vars must begin with uppercase +- local vars must begin with lowercase - reserved names: `nil`, `true`, `false`, `self`, `super`, and `Smalltalk` -##Variable scope: -- Global: defined in Dictionary Smalltalk and accessible by all objects in system - Special: (reserved) `Smalltalk`, `super`, `self`, `true`, `false`, & `nil` -- Method Temporary: local to a method -- Block Temporary: local to a block -- Pool: variables in a Dictionary object +##Variable scope: +- Global: defined in Dictionary Smalltalk and accessible by all objects in system - Special: (reserved) `Smalltalk`, `super`, `self`, `true`, `false`, & `nil` +- Method Temporary: local to a method +- Block Temporary: local to a block +- Pool: variables in a Dictionary object - Method Parameters: automatic local vars created as a result of message call with params - Block Parameters: automatic local vars created as a result of value: message call -- Class: shared with all instances of one class & its subclasses -- Class Instance: unique to each instance of a class +- Class: shared with all instances of one class & its subclasses +- Class Instance: unique to each instance of a class - Instance Variables: unique to each instance `"Comments are enclosed in quotes"` -`"Period (.) is the statement seperator"` +`"Period (.) is the statement separator"` ## Transcript: ``` @@ -53,7 +53,7 @@ Transcript cr. "carriage return / l Transcript endEntry. "flush the output buffer" ``` -##Assignment: +##Assignment: ``` | x y | x _ 4. "assignment (Squeak) <-" @@ -72,7 +72,7 @@ y := x deepCopy. "copy object and ins y := x veryDeepCopy. "complete tree copy using a dictionary" ``` -##Constants: +##Constants: ``` | b | b := true. "true constant" @@ -93,7 +93,7 @@ x := #('abc' 2 $a). "mixing of types all ``` -## Booleans: +## Booleans: ``` | b x y | x := 1. y := 2. @@ -132,7 +132,7 @@ b := $A isLowercase. "test if lower case ``` -## Arithmetic expressions: +## Arithmetic expressions: ``` | x | x := 6 + 3. "addition" @@ -190,7 +190,7 @@ x := 100 atRandom. "quick random number ``` -##Bitwise Manipulation: +##Bitwise Manipulation: ``` | b x | x := 16rFF bitAnd: 16r0F. "and bits" @@ -207,7 +207,7 @@ b := 16rFF noMask: 16r0F. "test if all bits se ``` -## Conversion: +## Conversion: ``` | x | x := 3.99 asInteger. "convert number to integer (truncates in Squeak)" @@ -223,15 +223,15 @@ x := 15 storeStringBase: 16. ``` -## Blocks: -- blocks are objects and may be assigned to a variable -- value is last expression evaluated unless explicit return -- blocks may be nested -- specification [ arguments | | localvars | expressions ] -- Squeak does not currently support localvars in blocks -- max of three arguments allowed -- `^`expression terminates block & method (exits all nested blocks) -- blocks intended for long term storage should not contain `^` +## Blocks: +- blocks are objects and may be assigned to a variable +- value is last expression evaluated unless explicit return +- blocks may be nested +- specification [ arguments | | localvars | expressions ] +- Squeak does not currently support localvars in blocks +- max of three arguments allowed +- `^`expression terminates block & method (exits all nested blocks) +- blocks intended for long term storage should not contain `^` ``` | x y z | @@ -241,18 +241,18 @@ Transcript show: (x value: 'First' value: 'Second'); cr. "use block with argu "x := [ | z | z := 1.]. *** localvars not available in squeak blocks" ``` -## Method calls: -- unary methods are messages with no arguments -- binary methods -- keyword methods are messages with selectors including colons standard categories/protocols: - initialize-release (methods called for new instance) -- accessing (get/set methods) -- testing (boolean tests - is) -- comparing (boolean tests with parameter -- displaying (gui related methods) -- printing (methods for printing) -- updating (receive notification of changes) -- private (methods private to class) -- instance-creation (class methods for creating instance) +## Method calls: +- unary methods are messages with no arguments +- binary methods +- keyword methods are messages with selectors including colons standard categories/protocols: - initialize-release (methods called for new instance) +- accessing (get/set methods) +- testing (boolean tests - is) +- comparing (boolean tests with parameter +- displaying (gui related methods) +- printing (methods for printing) +- updating (receive notification of changes) +- private (methods private to class) +- instance-creation (class methods for creating instance) ``` | x | x := 2 sqrt. "unary message" @@ -299,19 +299,19 @@ switch at: $C put: [Transcript show: 'Case C'; cr]. result := (switch at: $B) value. ``` -## Iteration statements: +## Iteration statements: ``` | x y | x := 4. y := 1. [x > 0] whileTrue: [x := x - 1. y := y * 2]. "while true loop" [x >= 4] whileFalse: [x := x + 1. y := y * 2]. "while false loop" -x timesRepeat: [y := y * 2]. "times repear loop (i := 1 to x)" +x timesRepeat: [y := y * 2]. "times repeat loop (i := 1 to x)" 1 to: x do: [:a | y := y * 2]. "for loop" 1 to: x by: 2 do: [:a | y := y / 2]. "for loop with specified increment" #(5 4 3) do: [:a | x := x + a]. "iterate over array elements" ``` -## Character: +## Character: ``` | x y | x := $A. "character assignment" @@ -320,7 +320,7 @@ y := x isUppercase. "test if upper case" y := x isLetter. "test if letter" y := x isDigit. "test if digit" y := x isAlphaNumeric. "test if alphanumeric" -y := x isSeparator. "test if seperator char" +y := x isSeparator. "test if separator char" y := x isVowel. "test if vowel" y := x digitValue. "convert to numeric digit value" y := x asLowercase. "convert to lower case" @@ -544,7 +544,7 @@ y := x asSet. "convert to set coll ``` ## Set: like Bag except duplicates not allowed -## IdentitySet: uses identity test (== rather than =) +## IdentitySet: uses identity test (== rather than =) ``` | b x y sum max | x := Set with: 4 with: 3 with: 2 with: 1. "create collection with up to 4 elements" @@ -603,7 +603,7 @@ y := x asBag. "convert to bag coll y := x asSet. "convert to set collection" ``` -##Associations: +##Associations: ``` | x y | x := #myVar->'hello'. |