For this "Terse Guide to SqueakGemStone Smalltalk", I've started with a copy of Terse Guide to Squeak ,
originally created by Chris Rathman, at http://www.angelfire.com/tx4/cus/notes/smalltalk.html
edited it to strike out features that don't appear in GemStone and colored those that are unique to
GemStone Smalltalk.
Checkout the GemStone/S 64 Bit Programming Guide for the complete story.
Hopefully you find this useful.
"************************************************************************
* 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 *
* - reserved names: nil, true, false, self, super, and Smalltalk *
* - a variable name may begin with or contain the character '_'. *
* - a variable name may contain up to 64 characters. *
* *
* Variable scope: *
* - Global: defined in Dictionary Smalltalk and accessible by all *
* objects in system *
* - Global: each user in the system has a SymbolList that contains *
* a collection of SymbolDictionaries. A Global is a key in one of *
* the SymbolDictionaries listed in the user's SymbolList. The *
* SymbolDictionary named #Globals is shared by all users and *
* contains the class definitions for the base system classes as *
* well as other shared Globals. Each user also has a *
* SymbolDictionary named #UserGlobals where user-specific globals *
* may be referenced. *
* - Special: (reserved) Smalltalk, super, self, true, false, & nil *
* - Method Temporary: local to a method *
* - Block Temporary: local to a block *
* - Pool: variables in a DictionarySymbolDictionary 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 *
* - Instance Variables: unique to each instance *
"************************************************************************
* *
* Optimized Selectors: *
* - The following selectors are optimized my the GemStone Smalltalk *
* compiler for kernel classes. Redefining a reserved selector has *
* no effect. *
* *
* ifTrue:, untilFalse, timesRepeat:, ifFalse:, untilTrue, *
* _isSymbol, ifTrue:ifFalse:, whileFalse:, _isInteger, *
* ifFalse:ifTrue: whileTrue:_isSmallInteger, _or:, *
* to:do:, ==, _and:, to:by:do:, ~~, *
* isKindOf:, includesIdentical, _class *
* *
* - The following selectors are optimized for the class SmallInteger. *
* You can redefine these methods in your application classes, but *
* redefinitions in the class SmallInteger have no effect. *
* *
* +, -, *, >=, = *
"Comments are enclosed in quotes"
"Period (.) is the statement seperator"
"************************************************************************
* Transcript: *
************************************************************************"
Transcript clear. "clear to transcript window"
Transcript show: 'Hello World'. "output string in transcript window"
Transcript nextPutAll: 'Hello World'. "output string in transcript window"
Transcript nextPut: $A. "output character in transcript window"
Transcript space. "output space character in transcript window"
Transcript tab. "output tab character in transcript window"
Transcript cr. "carriage return / linefeed"
'Hello' printOn: Transcript. "append print string into the window"
'Hello' storeOn: Transcript. "append store string into the window"
Transcript endEntry. "flush the output buffer"
"************************************************************************
* No GUI for GemStone: *
* *
* GemStone is an Application Server for Smalltalk and as such has no *
* GUI. The standard way to dump info from a GemStone application is *
* to write information to a log file. *
* *
* To avoid editting a number of the samples, I've not removed the *
* usage of 'Transcript show:', but to run the sample code in a *
* GemStone image, the string 'Transcript show:' with *
* 'GsFile gciLogServer:'. *
* *
* Creating a subclass of GsFile called Transcript and implementing a *
* class method called #show:, etc. would probably be sufficient. *
* *
************************************************************************"
GsFile gciLogServer: 'Hello World'. "output string to stdout of server process"
GsFile gciLogClient: 'Hello World'. "output string to stdout of client process"
"************************************************************************
* Assignment: *
************************************************************************"
| x y |
x _ 4. "assignment (Squeak) <-"
"In GemStone '_' used for assignment,
must be surrounded by white space"
x := 5. "assignment"
x := y := z := 6. "compound assignment"
x := (y := 6) + 1.
x := Object new. "bind to allocated instance of a class"
x := 123 class. "discover the object class"
x := Integer superclass. "discover the superclass of a class"
x := Object allInstances. "get an array of all instances of a class"
"In GemStone, allInstances can take a long time
to execute, since the entire repository is
scanned. Also note that the current
transaction is aborted."
x := Integer allSuperclasses. "get all superclasses of a class"
x := 1.2 hash. "hash value for object"
y := x copy. "copy object"
y := x shallowCopy. "copy object (not overridden)"
y := x deepCopy. "copy object and instance vars"
y := x veryDeepCopy. "complete tree copy using a dictionary"
"************************************************************************
* Constants: *
************************************************************************"
| x b |
b := true. "true constant"
b := false. "false constant"
x := nil. "nil object constant"
x := 1. "integer constants"
x := 3.14. "float constants"
x := 2e-2. "fractional constants"
x := 16r0F. "hex constant"
x := -1. "negative constants"
x := 'Hello'. "string constant"
x := 'I''m here'. "single quote escape"
x := $A. "character constant"
x := $ . "character constant (space)"
x := #aSymbol. "symbol constants"
x := #(3 2 1). "array constants"
x := #('abc' 2 $a). "mixing of types allowed"
"************************************************************************
* Booleans: *
************************************************************************"
| b x y |
x := 1. y := 2.
b := (x = y). "equals"
b := (x ~= y). "not equals"
b := (x == y). "identical"
b := (x ~~ y). "not identical"
b := (x > y). "greater than"
b := (x < y). "less than"
b := (x >= y). "greater than or equal"
b := (x <= y). "less than or equal"
b := b not. "boolean not"
b := (x < 5) & (y > 1). "boolean and"
b := (x < 5) | (y > 1). "boolean or"
b := (x < 5) and: [y > 1]. "boolean and (short-circuit)"
b := (x < 5) or: [y > 1]. "boolean or (short-circuit)"
b := (x < 5) eqv: (y > 1). "test if both true or both false"
b := (x < 5) xor: (y > 1). "test if one true and other false"
b := 5 between: 3 and: 12. "between (inclusive)"
b := 123 isKindOf: Number. "test if object is class or subclass of"
b := 123 isMemberOf: SmallInteger. "test if object is type of class"
b := 123 respondsTo: sqrt. "test if object responds to message"
b := x isNil. "test if object is nil"
b := x isZero. "test if number is zero"
b := x positive. "test if number is positive"
b := x strictlyPositive. "test if number is greater than zero"
b := x negative. "test if number is negative"
b := x even. "test if number is even"
b := x odd. "test if number is odd"
b := x isLiteral. "test if literal constant"
b := x isInteger. "test if object is integer"
b := x isFloat. "test if object is float"
b := x isNumber. "test if object is number"
b := $A isUppercase. "test if upper case character"
b := $A isLowercase. "test if lower case character"
b := x isCommitted. "test if object is persistent"
b := x isSpecial. "test if object is special
(SmallInteger, SmallDouble,
Character, etc.)."
b := x canBeWritten. "test if you have permission to
write object"
"************************************************************************
* Arithmetic expressions: *
* GemStone has a SmallDouble class that represents a floating point *
* number in 61 bits. Instances of SmallDouble class are Specials, *
* (like SmallInteger) and consume no object storage. All floating *
* point numbers that can be represented in 61 bits *
* instances of SmallDouble. *
************************************************************************"
| x |
x := 6 + 3. "addition"
x := 6 - 3. "subtraction"
x := 6 * 3. "multiplication"
x := 1 + 2 * 3. "evaluation always left to right (1 + 2) * 3"
x := 5 / 3. "division with fractional result"
x := 5.0 / 3.0. "division with float result"
x := 5.0 // 3.0. "integer divide"
x := 5.0 3.0. "integer remainder"
x := -5. "unary minus"
x := 5 sign. "numeric sign (1, -1 or 0)"
x := 5 negated. "negate receiver"
x := 1.2 integerPart. "integer part of number (1.0)"
x := 1.2 fractionPart. "fractional part of number (0.2)"
x := 5 reciprocal. "reciprocal function"
x := 6 * 3.1. "auto convert to float"
x := 5 squared. "square function"
x := 25 sqrt. "square root"
x := 5 raisedTo: 2. "power function"
x := 5 raisedToInteger: 2. "power function with integer"
x := 5 exp. "exponential"
x := -5 abs. "absolute value"
x := 3.99 rounded. "round"
x := 3.99 truncated. "truncate"
x := 3.99 roundTo: 1. "round to specified decimal places"
x := 3.99 truncateTo: 1. "truncate to specified decimal places"
x := 3.99 floor. "truncate"
x := 3.99 ceiling. "round up"
x := 5 factorial. "factorial"
x := -5 quo: 3. "integer divide rounded toward zero"
x := -5 rem: 3. "integer remainder rounded toward zero"
x := 28 gcd: 12. "greatest common denominator"
x := 28 lcm: 12. "least common multiple"
x := 100 ln. "natural logarithm"
x := 100 log. "base 10 logarithm"
x := 100 log: 10. "logarithm with specified base"
x := 100 floorLog: 10. "floor of the log"
x := 180 degreesToRadians. "convert degrees to radians"
x := 3.14 radiansToDegrees. "convert radians to degrees"
x := 0.7 sin. "sine"
x := 0.7 cos. "cosine"
x := 0.7 tan. "tangent"
x := 0.7 arcSin. "arcsine"
x := 0.7 arcCos. "arccosine"
x := 0.7 arcTan. "arctangent"
x := 10 max: 20. "get maximum of two numbers"
x := 10 min: 20. "get minimum of two numbers"
x := Float pi. "pi"
x := Float e. "exp constant"
x := Float infinity. "infinity"
x := Float nan. "not-a-number"
x := Random new next; yourself. x next."random number stream (0.0 to 1.0)"
x := 100 atRandom. "quick random number"
x := Float fromString: 'PlusInfinity'. "infinity"
x := Float fromString: 'PlusQuietNaN'. "not-a-number"
x := SmallDouble pi. "pi"
"************************************************************************
* Bitwise Manipulation: *
************************************************************************"
| b x |
x := 16rFF bitAnd: 16r0F. "and bits"
x := 16rF0 bitOr: 16r0F. "or bits"
x := 16rFF bitXor: 16r0F. "xor bits"
x := 16rFF bitInvert. "invert bits"
x := 16r0F bitShift: 4. "left shift"
x := 16rF0 bitShift: -4. "right shift"
"x := 16r80 bitAt: 7." "bit at position (0|1) [!Squeak]"
x := 16r80 highbit. "position of highest bit set"
b := 16rFF allMask: 16r0F. "test if all bits set in mask set in receiver"
b := 16rFF anyMask: 16r0F. "test if any bits set in mask set in receiver"
b := 16rFF noMask: 16r0F. "test if all bits set in mask clear in receiver"
"************************************************************************
* Conversion: *
************************************************************************"
| x |
x := 3.99 asInteger. "convert number to integer (truncates in Squeak)"
x := 3.99 asFraction. "convert number to fraction"
x := 3 asFloat. "convert number to float"
x := 65 asCharacter. "convert integer to character"
x := $A asciiValue. "convert character to integer"
x := 3.99 printString. "convert object to string via printOn:"
x := 3.99 storeString. "convert object to string via storeOn:"
x := 15 radix: 16. "convert to string in given base"
x := 15 printStringBase: 16.
x := 15 storeStringBase: 16.
x := 15 printStringRadix: 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 ^ *
************************************************************************"
| x y z |
x := [ y := 1. z := 2. ]. x value. "simple block usage"
x := [ :argOne :argTwo |
argOne, ' and ' , argTwo.]. "set up block with argument passing"
Transcript show:
(x value: 'One' value: 'Two'); cr. "use block with argument passing"
x := [ | z | z := 1.]. "localvars in block"
x := [:x | x := x + 1]. "assignment to block argument"
x := [:t]. x value: 1. "single argument empty block"
x := [:t|]. x value: 1. "single argument empty block"
"************************************************************************
* Method calls: *
* - unary methods are messages with no arguments *
* - binary methods *
* - keyword methods are messages with selectors including colons *
* - by convention, selectors beginning with '_' are private methods *
* *
* 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"
x := 2 raisedTo: 10. "keyword message"
x := 194 * 9. "binary message"
Transcript show: "combination (chaining)"
(194 * 9) printString; cr.
x := 2 perform: #sqrt. "indirect method invocation"
Transcript "Cascading - send multiple messages to receiver"
show: 'hello ';
show: 'world';
cr.
x := 3 + 2; * 100. "result=300. Sends message to same receiver (3)"
"************************************************************************
* Conditional Statements: *
************************************************************************"
| x |
x > 10 ifTrue: [Transcript show: 'ifTrue'; cr]. "if then"
x > 10 ifFalse: [Transcript show: 'ifFalse'; cr]. "if else"
x > 10 "if then else"
ifTrue: [Transcript show: 'ifTrue'; cr]
ifFalse: [Transcript show: 'ifFalse'; cr].
x > 10 "if else then"
ifFalse: [Transcript show: 'ifFalse'; cr]
ifTrue: [Transcript show: 'ifTrue'; cr].
Transcript
show:
(x > 10
ifTrue: ['ifTrue']
ifFalse: ['ifFalse']);
cr.
Transcript "nested if then else"
show:
(x > 10
ifTrue: [x > 5
ifTrue: ['A']
ifFalse: ['B']]
ifFalse: ['C']);
cr.
switch := Dictionary new. "switch functionality"
switch at: $A put: [Transcript show: 'Case A'; cr].
switch at: $B put: [Transcript show: 'Case B'; cr].
switch at: $C put: [Transcript show: 'Case C'; cr].
result := (switch at: $B) value.
"************************************************************************
* 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)"
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: *
************************************************************************"
| x y |
x := $A. "character assignment"
y := x isLowercase. "test if lower case"
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 isVowel. "test if vowel"
y := x digitValue. "convert to numeric digit value"
y := x asLowercase. "convert to lower case"
y := x asUppercase. "convert to upper case"
y := x asciiValue. "convert to numeric ascii value"
y := x asString. "convert to string"
b := $A <= $B. "comparison"
y := $A max: $B.
"************************************************************************
* Symbol: *
************************************************************************"
| b x y |
x := #Hello. "symbol assignment"
y := 'String', 'Concatenation'. "symbol concatenation (result is string)"
b := x isEmpty. "test if symbol is empty"
y := x size. "string size"
y := x at: 2. "char at location"
y := x copyFrom: 2 to: 4. "substring"
y := x indexOf: $e ifAbsent: [0]. "first position of character within string"
x do: [:a |
Transcript show: a printString; cr]. "iterate over the string"
b := x conform: [:a | (a >= $a) & (a <= $z)]."test if all elements meet condition"
y := x select: [:a | a > $a]. "return all elements that meet condition"
y := x asString. "convert symbol to string"
y := x asText. "convert symbol to text"
y := x asArray. "convert symbol to array"
y := x asOrderedCollection. "convert symbol to ordered collection"
y := x asSortedCollection. "convert symbol to sorted collection"
y := x asBag. "convert symbol to bag collection"
y := x asSet. "convert symbol to set collection"
"************************************************************************
* String: *
************************************************************************"
| b x y |
x := 'This is a string'. "string assignment"
x := 'String', 'Concatenation'. "string concatenation"
b := x isEmpty. "test if string is empty"
y := x size. "string size"
y := x at: 2. "char at location"
y := x copyFrom: 2 to: 4. "substring"
y := x indexOf: $a ifAbsent: [0]. "first position of character within string"
x := String new: 4. "allocate string object"
x "set string elements"
at: 1 put: $a;
at: 2 put: $b;
at: 3 put: $c;
at: 4 put: $e.
x := String with: $a with: $b with: $c with: $d. "set up to 4 elements at a time"
x do: [:a |
Transcript show: a printString; cr]. "iterate over the string"
b := x conform: [:a | (a >= $a) & (a <= $z)]."test if all elements meet condition"
y := x select: [:a | a > $a]. "return all elements that meet condition"
y := x asSymbol. "convert string to symbol"
y := x asArray. "convert string to array"
x := 'ABCD' asByteArray. "convert string to byte array"
y := x asOrderedCollection. "convert string to ordered collection"
y := x asSortedCollection. "convert string to sorted collection"
y := x asBag. "convert string to bag collection"
y := x asSet. "convert string to set collection"
y := x shuffled. "randomly shuffle string"
"************************************************************************
* Array: Fixed length collection *
* Array: Variable length collection with up to SmallInteger *
* maximumValue elements. *
* ByteArray: Array limited to byte elements (0-255) *
* WordArray: Array limited to word elements (0-2^32) *
************************************************************************"
| b x y sum max |
x := #[ "array constructor"
'one'->1,
'two'->2,
'three'->3,
'four'->4].
x size: 0. "truncate array"
x := #(4 3 2 1). "constant array"
x := Array. "create array with up to 4 elements"
with: 5
with: 4
with: 3
with: 2
x := Array new: 4. "allocate an array with specified size"
x "set array elements"
at: 1 put: 5;
at: 2 put: 4;
at: 3 put: 3;
at: 4 put: 2.
b := x isEmpty. "test if array is empty"
y := x size. "array size"
y := x at: 4. "get array element at index"
b := x includes: 3. "test if element is in array"
y := x copyFrom: 2 to: 4. "subarray"
y := x indexOf: 3 ifAbsent: [0]. "first position of element within array"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | "iterate over the array"
Transcript show: a printString; cr].
b := x conform: [:a | (a >= 1) & (a <= 4)]."test if all elements meet condition"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x "find position of first element that passes test"
detect: [:a | a > 3]
ifNone: [].
sum := 0.
x do: [:a | sum := sum + a]. sum. "sum array elements"
sum := 0.
1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum array elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum array elements"
max := x inject: 0 into: [:a :c | (a > c) "find max element in array"
ifTrue: [a]
ifFalse: [c]].
y := x shuffled. "randomly shuffle collection"
y := x asArray. "convert to array"
y := x asByteArray. "convert to byte array"
y := x asWordArray. "convert to word array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"
"************************************************************************
* OrderedCollection: acts like an expandable array *
* In GemStone Array and OrderedCollection are very similar *
************************************************************************"
| b x y sum max |
x := OrderedCollection "create collection with up to 4 elements"
with: 4
with: 3
with: 2
with: 1.
x := OrderedCollection new. "allocate collection"
x "add element to collection"
add: 3;
add: 2;
add: 1;
add: 4;
yourself.
y := x addFirst: 5. "add element at beginning of collection"
y := x removeFirst. "remove first element in collection"
y := x addLast: 6. "add element at end of collection"
y := x removeLast. "remove last element in collection"
y := x addAll: #(7 8 9). "add multiple elements to collection"
y := x removeAll: #(7 8 9). "remove multiple elements from collection"
x at: 2 put: 3. "set element at index"
y := x remove: 5 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
y := x at: 2. "retrieve element at index"
y := x first. "retrieve first element in collection"
y := x last. "retrieve last element in collection"
b := x includes: 5. "test if element is in collection"
y := x copyFrom: 2 to: 3. "subcollection"
y := x indexOf: 3 ifAbsent: [0]. "first position of element within collection"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x "find position of first element that passes test"
detect: [:a | a > 3]
ifNone: [].
sum := 0. "sum elements"
x do: [:a | sum := sum + a].
sum.
sum := 0.
1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x "find max element in collection"
inject: 0
into: [:a :c |
(a > c)
ifTrue: [a]
ifFalse: [c]].
y := x shuffled. "randomly shuffle collection"
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"
"************************************************************************
* SortedCollection: like OrderedCollection except order of elements *
* determined by sorting criteria *
************************************************************************"
| b x y sum max |
x := SortedCollection "create collection with up to 4 elements"
with: 4
with: 3
with: 2
with: 1.
x := SortedCollection new. "allocate collection"
x := SortedCollection "set sort criteria"
sortBlock: [:a :c | a > c].
x "add element to collection"
add: 3;
add: 2;
add: 1;
add: 4;
yourself.
y := x addFirst: 5. "add element at beginning of collection"
y := x removeFirst. "remove first element in collection"
y := x addLast: 6. "add element at end of collection"
y := x removeLast. "remove last element in collection"
y := x addAll: #(7 8 9). "add multiple elements to collection"
y := x removeAll: #(7 8 9). "remove multiple elements from collection"
y := x remove: 5 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
y := x at: 2. "retrieve element at index"
y := x first. "retrieve first element in collection"
y := x last. "retrieve last element in collection"
b := x includes: 5. "test if element is in collection"
y := x copyFrom: 2 to: 3. "subcollection"
y := x indexOf: 3 ifAbsent: [0]. "first position of element within collection"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x "find position of first element that passes test"
detect: [:a | a > 3]
ifNone: [].
sum := 0. "sum elements"
x do: [:a | sum := sum + a].
sum.
sum := 0.
1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x "find max element in collection"
inject: 0
into: [:a :c |
(a > c)
ifTrue: [a]
ifFalse: [c]].
y := x shuffled. "randomly shuffle collection"
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"
"************************************************************************
* Bag: like OrderedCollection except elements are in no *
* particular order *
* RcIdentityBag: reduced conflict class allows for concurrent updates *
************************************************************************"
| b x y sum max w z |
x := Bag "create collection with up to 4 elements"
with: 4
with: 3
with: 2
with: 1.
x := Bag new. "allocate collection"
x "add element to collection"
add: 3;
add: 2;
add: 1;
add: 4;
yourself.
x add: 3 withOccurrences: 2. "add multiple copies to collection"
y := x addAll: #(7 8 9). "add multiple elements to collection"
y := x removeAll: #(7 8 9). "remove multiple elements from collection"
y := x remove: 4 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
b := x includes: 3. "test if element is in collection"
y := x occurrencesOf: 3. "number of times object in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x "find position of first element that passes test"
detect: [:a | a > 3]
ifNone: [].
x "create index on elements of x"
createEqualityIndexOn: ''
withLastElementClass: Integer.
w := #[ "array constructor"
'one'->1,
'two'->2,
'three'->3,
'four'->4].
z := w asBag.
z "create equality index on instance variable 'key' of elements for z"
createEqualityIndexOn: 'key'
withLastElementClass: String.
z "create equality index on instance variable 'value' of elements for z"
createEqualityIndexOn: 'value'
withLastElementClass: Number.
z "create identity index on instance variable 'value' of elements for z"
createIdentityIndexOn: 'value'.
y := x select: {:a | a.key > 2}. "return collection of elements that pass test, using equality index"
y := z reject: {:a | a.value < 'one'}. "return collection of elements that fail test, using equality index"
y := z "find position of first element that passes test, using identity index"
detect: {:a | a == (w at: 1)}
ifNone: [].
z removeEqualityIndexOn: 'key'. "remove equality index on instance variable 'key' of elements for z"
z removeIdentityIndexOn: 'value'. "remove identity index on instance variable 'value' of elements for z"
x removeAllIndexes. "remove all indexes on x"
IndexManager current removeAllIndexes. "remove all indexes on all collections in system"
sum := 0. "sum elements"
x do: [:a | sum := sum + a].
sum.
sum := 0.
1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x "find max element in collection"
inject: 0
into: [:a :c |
(a > c)
ifTrue: [a]
ifFalse: [c]].
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"
"************************************************************************
* Set: like Bag except duplicates not allowed *
* IdentitySet: uses identity test (== rather than =) *
************************************************************************"
| b x y sum max w z |
x := Set "create collection with up to 4 elements"
with: 4
with: 3
with: 2
with: 1.
x := Set new. "allocate collection"
x "add element to collection"
add: 3;
add: 2;
add: 1;
add: 4;
yourself.
y := x addAll: #(7 8 9). "add multiple elements to collection"
y := x removeAll: #(7 8 9). "remove multiple elements from collection"
y := x remove: 4 ifAbsent: []. "remove element from collection"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
b := x includes: 3. "test if element is in collection"
x do: [:a | Transcript show: a printString; cr]. "iterate over the collection"
b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x "find position of first element that passes test"
detect: [:a | a > 3]
ifNone: [].
x "create index on elements of x"
createEqualityIndexOn: ''
withLastElementClass: Integer.
w := #[ "array constructor"
'one'->1,
'two'->2,
'three'->3,
'four'->4].
z := w asSet.
z "create equality index on instance variable 'key' of elements for z"
createEqualityIndexOn: 'key'
withLastElementClass: String.
z "create equality index on instance variable 'value' of elements for z"
createEqualityIndexOn: 'value'
withLastElementClass: Number.
z "create identity index on instance variable 'value' of elements for z"
createIdentityIndexOn: 'value'.
y := x select: {:a | a.key > 2}. "return collection of elements that pass test, using equality index"
y := z reject: {:a | a.value < 'one'}. "return collection of elements that fail test, using equality index"
y := z "find position of first element that passes test, using identity index"
detect: {:a | a == (w at: 1)}
ifNone: [].
z removeEqualityIndexOn: 'key'. "remove equality index on instance variable 'key' of elements for z"
z removeIdentityIndexOn: 'value'. "remove identity index on instance variable 'value' of elements for z"
x removeAllIndexes. "remove all indexes on x"
IndexManager current removeAllIndexes. "remove all indexes on all collections in system"
sum := 0. "sum elements"
x do: [:a | sum := sum + a].
sum.
sum := 0.
1 to: (x size) do: [:a | sum := sum + (x at: a)]. "sum elements"
sum := x inject: 0 into: [:a :c | a + c]. "sum elements"
max := x "find max element in collection"
inject: 0
into: [:a :c |
(a > c)
ifTrue: [a]
ifFalse: [c]].
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"
"************************************************************************
* Interval: *
************************************************************************"
| b x y sum max |
x := Interval from: 5 to: 10. "create interval object"
x := 5 to: 10.
x := Interval "create interval object with specified increment"
from: 5
to: 10
by: 2.
x := 5 to: 10 by: 2.
b := x isEmpty. "test if empty"
y := x size. "number of elements"
x includes: 9. "test if element is in collection"
x do: [:k | Transcript show: k printString; cr]. "iterate over interval"
b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition"
y := x select: [:a | a > 7]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x "find position of first element that passes test"
detect: [:a | a > 3]
ifNone: [].
sum := 0. "sum elements"
x do: [:a | sum := sum + a].
sum.
sum := 0. "sum elements"
1
to: (x size)
do: [:a |
sum := sum + (x at: a)].
sum := x "sum elements"
inject: 0
into: [:a :c | a + c].
max := x "find max element in collection"
inject: 0 into: [:a :c | (a > c)
ifTrue: [a]
ifFalse: [c]].
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"
"************************************************************************
* Associations: *
************************************************************************"
| x y |
x := #myVar->'hello'.
y := x key.
y := x value.
"************************************************************************
* Dictionary: *
* IdentityDictionary: uses identity test (== rather than =) *
************************************************************************"
| b x y |
x := Dictionary new. "allocate collection"
x "add element to collection"
add: #a->4;
add: #b->3;
add: #c->1;
add: #d->2;
yourself.
x at: #e put: 3. "set element at index"
b := x isEmpty. "test if empty"
y := x size. "number of elements"
y := x at: #a ifAbsent: []. "retrieve element at index"
y := x "retrieve key for given value with error block"
keyAtValue: 3
ifAbsent: [].
y := x "remove element from collection"
removeKey: #e
ifAbsent: [].
b := x includes: 3. "test if element is in values collection"
b := x includesKey: #a. "test if element is in keys collection"
y := x occurrencesOf: 3. "number of times object in collection"
y := x keys. "set of keys"
y := x values. "bag of values"
x do: [:a | Transcript show: a printString; cr]. "iterate over the values collection"
x keysDo: [:a | Transcript show: a printString; cr]. "iterate over the keys collection"
x associationsDo: [:a | Transcript show: a printString; cr]."iterate over the associations"
x keysAndValuesDo: [:aKey :aValue | Transcript "iterate over keys and values"
show: aKey printString; space;
show: aValue printString; cr].
b := x conform: [:a | (a >= 1) & (a <= 4)]. "test if all elements meet condition"
y := x select: [:a | a > 2]. "return collection of elements that pass test"
y := x reject: [:a | a < 2]. "return collection of elements that fail test"
y := x collect: [:a | a + a]. "transform each element for new collection"
y := x "find position of first element that passes test"
detect: [:a | a > 3]
ifNone: [].
sum := 0. "sum elements"
x do: [:a | sum := sum + a].
sum.
sum := x "sum elements"
inject: 0
into: [:a :c | a + c].
max := x "find max element in collection"
inject: 0
into:
[:a :c | (a > c)
ifTrue: [a]
ifFalse: [c]].
y := x asArray. "convert to array"
y := x asOrderedCollection. "convert to ordered collection"
y := x asSortedCollection. "convert to sorted collection"
y := x asBag. "convert to bag collection"
y := x asSet. "convert to set collection"
Smalltalk at: #CMRGlobal put: 'CMR entry'. "put global in Smalltalk Dictionary"
x := Smalltalk at: #CMRGlobal. "read global from Smalltalk Dictionary"
Transcript show: (CMRGlobal printString). "entries are directly accessible by name"
Smalltalk keys do: [ :k | "print out all classes"
((Smalltalk at: k) isKindOf: Class)
ifFalse: [Transcript show: k printString; cr]].
Smalltalk at: #CMRDictionary put: (Dictionary new). "set up user defined dictionary"
Globals at: #CMRGlobal put: 'CMR entry'. "put Global in UserGlobals Dictionary"
Globals at: #CMRGlobal1 put: 'CMR entry1'. "put Global in UserGlobals Dictionary" UserGlobals at: #CMRGlobal2 put: 'CMR entry2'. "put Global in UserGlobals Dictionary" x := Globals at: #CMRGlobal1. "read global from Globals" x := UserGlobals at: #CMRGlobal2. "read global from UserGlobals" x := GsSession currentSession objectNamed: #CMRGlobal. "read global from users's symbolList"
Transcript show: (CMRGlobal printString). "entries are directly accessible
by name"
ClassOrganizer new classNames do: [:className | "print out all classes"
Transcript show: classname; cr].
Globals at: #CMRDictionary put: (Dictionary new). "set up user defined dictionary"
CMRDictionary at: #MyVar1 put: 'hello1'. "put entry in dictionary"
CMRDictionary add: #MyVar2->'hello2'. "add entry to dictionary use key->value combo"
CMRDictionary size. "dictionary size"
CMRDictionary keys do: [ :k | "print out keys in dictionary"
Transcript show: k printString; cr].
CMRDictionary values do: [ :k | "print out values in dictionary"
Transcript show: k printString; cr].
CMRDictionary keysAndValuesDo: [:aKey :aValue | "print out keys and values"
Transcript
show: aKey printString;
space;
show: aValue printString;
cr].
CMRDictionary associationsDo: [:aKeyValue | "another iterator for printing key values"
Transcript show: aKeyValue printString; cr].
Smalltalk removeKey: #CMRGlobal ifAbsent: []. "remove entry from Smalltalk dictionary"
Smalltalk removeKey: #CMRDictionary ifAbsent: []. "remove user dictionary from Smalltalk dictionary"
Globals removeKey: #CMRGlobal ifAbsent: []. "remove entry from Smalltalk dictionary"
Globals removeKey: #CMRDictionary ifAbsent: []. "remove user dictionary from Smalltalk dictionary"
"************************************************************************
* Internal Stream: *
************************************************************************"
| b x ios |
ios := ReadStream on: 'Hello read stream'.
ios := ReadStream on: 'Hello read stream' from: 1 to: 5.
[(x := ios nextLine) notNil]
whileTrue: [Transcript show: x; cr].
ios position: 3.
ios position.
x := ios next.
x := ios peek.
x := ios contents.
b := ios atEnd.
ios := ReadWriteStream on: 'Hello read stream'.
ios := ReadWriteStream on: 'Hello read stream' from: 1 to: 5.
ios := ReadWriteStream with: 'Hello read stream'.
ios := ReadWriteStream with: 'Hello read stream' from: 1 to: 10.
ios position: 0.
[(x := ios nextLine) notNil]
whileTrue: [Transcript show: x; cr].
ios position: 6.
ios position.
ios nextPutAll: 'Chris'.
x := ios next.
x := ios peek.
x := ios contents.
b := ios atEnd.
"************************************************************************
* FileStream: *
************************************************************************"
| b x ios |
ios := FileStream newFileNamed: 'ios.txt'.
ios nextPut: $H; cr.
ios nextPutAll: 'Hello File'; cr.
'Hello File' printOn: ios.
'Hello File' storeOn: ios.
ios close.
ios := FileStream oldFileNamed: 'ios.txt'.
[(x := ios nextLine) notNil]
whileTrue: [Transcript show: x; cr].
ios position: 3.
x := ios position.
x := ios next.
x := ios peek.
b := ios atEnd.
ios close.
"************************************************************************
* GsFile: *
************************************************************************"
| b x ios |
ios := GsFile openWrite: 'ios.txt'.
ios nextPut: $H; cr.
ios nextPutAll: 'Hello File'; cr.
ios close.
ios := GsFile openRead: 'ios.txt'.
[(x := ios nextLine) notNil]
whileTrue: [Transcript show: x; cr].
ios position: 3.
x := ios position.
x := ios next.
x := ios peek.
b := ios atEnd.
ios close.
"************************************************************************
* Date: *
************************************************************************"
| x y |
x := Date today. "create date for today"
x := Date dateAndTimeNow. "create date from current time/date"
x := Date readFromString: '01/02/1999'. "create date from formatted string"
x := Date fromString: '01/02/1999'. "create date from formatted string"
x := Date newDay: 12 month: #July year: 1999. "create date from parts"
x := Date fromDays: 36000. "create date from elapsed days since 1/1/1901"
y := Date dayOfWeek: #Monday. "day of week as int (1-7)"
y := Date indexOfMonth: #January. "month of year as int (1-12)"
y := Date daysInMonth: 2 forYear: 1996. "day of month as int (1-31)"
y := Date daysInYear: 1996. "days in year (365|366)"
y := Date nameOfDay: 1 "weekday name (#Monday,...)"
y := Date nameOfMonth: 1. "month name (#January,...)"
y := Date leapYear: 1996. "1 if leap year; 0 if not leap year"
y := Date isLeap: 1996. "true if leap year; false if not leap year"
y := x weekday. "day of week (#Monday,...)"
y := x weekDayName. "day of week ('Monday',...)"
y := x previous: #Monday. "date for previous day of week"
y := x dayOfMonth. "day of month (1-31)"
y := x day. "day of year (1-366)"
y := x firstDayOfMonth. "day of year for first day of month"
y := x monthName. "month of year (#January,...)"
y := x monthIndex. "month of year (1-12)"
y := x daysInMonth. "days in month (1-31)"
y := x year. "year (19xx)"
y := x daysInYear. "days in year (365|366)"
y := x daysLeftInYear. "days left in year (364|365)"
y := x asSeconds. "seconds elapsed since 1/1/1901"
y := x addDays: 10. "add days to date object"
y := x subtractDays: 10. "subtract days to date object"
y := x subtractDate: (Date today). "subtract date (result in days)"
y := x printFormat: #(2 1 3 $/ 1 1). "print formatted date"
y := x
asStringUsingFormat: #(1 2 3 $ 3 1 $: false )."print formatted date"
b := (x <= Date today). "comparison"
"************************************************************************
* Time: *
************************************************************************"
| x y |
x := Time now. "create time from current time"
x := Time dateAndTimeNow. "create time from current time/date"
x := Time "create time from formatted string"
readFromString: '3:47:26 pm'.
x := Time fromString: '3:47:26 pm'. "create time from formatted string"
x := Time "create time from elapsed time from midnight"
fromSeconds: (60 * 60 * 4).
y := Time millisecondClockValue. "milliseconds since midnight"
y := Time totalSeconds. "total seconds since 1/1/1901"
y := x seconds. "seconds past minute (0-59)"
y := x minutes. "minutes past hour (0-59)"
y := x hours. "hours past midnight (0-23)"
y := x addTime: (Time now). "add time to time object"
y := x subtractTime: (Time now). "subtract time to time object"
y := x asSeconds. "convert time to seconds"
x := Time millisecondsToRun: [ "timing facility"
1
to: 1000
do: [:index |
y := 3.14 * index]].
x := Time millisecondsElapsedTime: [ "timing facility"
1
to: 1000
do: [:index |
y := 3.14 * index]].
b := (x <= Time now). "comparison"
"************************************************************************
* Point: *
************************************************************************"
| x y |
x := 200@100. "obtain a new point"
y := x x. "x coordinate"
y := x y. "y coordinate"
x := 200@100 negated. "negates x and y"
x := (-200@-100) abs. "absolute value of x and y"
x := (200.5@100.5) rounded. "round x and y"
x := (200.5@100.5) truncated. "truncate x and y"
x := 200@100 + 100. "add scale to both x and y"
x := 200@100 - 100. "subtract scale from both x and y"
x := 200@100 * 2. "multiply x and y by scale"
x := 200@100 / 2. "divide x and y by scale"
x := 200@100 // 2. "divide x and y by scale"
x := 200@100 \\ 3. "remainder of x and y by scale"
x := 200@100 + 50@25. "add points"
x := 200@100 - 50@25. "subtract points"
x := 200@100 * 3@4. "multiply points"
x := 200@100 // 3@4. "divide points"
x := 200@100 max: 50@200. "max x and y"
x := 200@100 min: 50@200. "min x and y"
x := 20@5 dotProduct: 10@2. "sum of product (x1*x2 + y1*y2)"
"************************************************************************
* Rectangle: *
************************************************************************"
Rectangle fromUser.
"************************************************************************
* Pen: *
************************************************************************"
| myPen |
Display restoreAfter: [
Display fillWhite.
myPen := Pen new. "get graphic pen"
myPen squareNib: 1.
myPen color: (Color blue). "set pen color"
myPen home. "position pen at center of display"
myPen up. "makes nib unable to draw"
myPen down. "enable the nib to draw"
myPen north. "points direction towards top"
myPen turn: -180. "add specified degrees to direction"
myPen direction. "get current angle of pen"
myPen go: 50. "move pen specified number of pixels"
myPen location. "get the pen position"
myPen goto: 200@200. "move to specified point"
myPen place: 250@250. "move to specified point without drawing"
myPen print: 'Hello World' withFont: (TextStyle default fontAt: 1).
Display extent. "get display width@height"
Display width. "get display width"
Display height. "get display height"
].
"************************************************************************
* System: *
************************************************************************"
System transactionMode: #manualBegin. "system 'in transaction' only between begin and commit or abort"
System beginTransaction. "begin transaction"
UserGlobals at: #TransTest put: 1. "make a change to persistent object"
System commitTransaction. "commitanges and leave transaction"
System beginTransaction. "start another transaction"
UserGlobals at: #TransTest put: 2. "make change"
System abortTransaction. "revert changes made since begin transaction"
System transactionMode: #autoBegin. "system always 'in transaction'"
UserGlobals at: #TransTest put: 1. "make change"
System commitTransaction. "commit changes and stay in transaction"
UserGlobals at: #TransTest put: 2. "make change"
System abortTransaction. "revert changes made since last commit or abort"
"************************************************************************
* Repository: *
************************************************************************"
SystemRepository "singleton instance of class Repository"
SystemRepository fullBackupTo: '/home/dhenrich/backup.dbf'. "initiate backup of repository"
SystemRepository restoreFromBackup: '/home/dhenrich/backup.dbf'. "initiate restore of repository from previously saved backup"
SystemRepository restoreFromCurrentLogs. "restore transactions committed since backup file created"
SystemRepository commitRestore. "finish restore from backup process"
SystemRepository listInstances: #[ Bag, Set ]. "search repository and return list of instances of the given classes"
SystemRepository markForCollection. "perform repository-wide garbage collection"
"************************************************************************
* Dynamic Message Calling/Compiling: *
************************************************************************"
| receiver message result argument keyword1 keyword2 argument1 argument2 |
"unary message"
receiver := 5.
message := 'factorial' asSymbol.
result := receiver perform: message.
result := Compiler evaluate: ((receiver storeString), ' ', message).
result :=
(Message new setSelector: message arguments: #()) sentTo: receiver.
"binary message"
receiver := 1.
message := '+' asSymbol.
argument := 2.
result := receiver perform: message withArguments: (Array with: argument).
result := Compiler evaluate: ((receiver storeString), ' ', message, ' ', (argument storeString)).
result :=
(Message new setSelector: message arguments: (Array with: argument))
sentTo: receiver.
result := ((receiver storeString), ' ', message, ' ', (argument storeString)) evaluate.
"keyword messages"
receiver := 12.
keyword1 := 'between:' asSymbol.
keyword2 := 'and:' asSymbol.
argument1 := 10.
argument2 := 20.
result := receiver
perform: (keyword1, keyword2) asSymbol
withArguments: (Array with: argument1 with: argument2).
result := Compiler evaluate:
((receiver storeString),
' ',
keyword1,
(argument1 storeString) ,
' ',
keyword2,
(argument2 storeString)).
result := (Message
new
setSelector: (keyword1, keyword2) asSymbol
arguments: (Array with: argument1 with: argument2))
sentTo: receiver.
receiver := ((receiver storeString),
' ',
keyword1,
(argument1 storeString) ,
' ',
keyword2,
(argument2 storeString)).
"************************************************************************
* class/meta-class: *
************************************************************************"
| b x |
x := String name. "class name"
x := String category. "organization category"
x := String comment. "class comment"
x := "subclass type - subclass: variableSubclass, etc"
String kindOfSubclass.
String description detailsAboutClass. "class comment"
x := String definition. "class definition"
x := String instVarNames. "immediate instance variable names"
x := String allInstVarNames. "accumulated instance variable names"
x := String classVarNames. "immediate class variable names"
x := String allClassVarNames. "accumulated class variable names"
x := String sharedPools. "immediate dictionaries used as shared pools"
x := String allSharedPools. "accumulated dictionaries used as shared pools"
x := String selectors. "message selectors for class"
x := String sourceCodeAt: #size. "source code for specified method"
x := String allInstances. "collection of all instances of class"
x := String superclass. "immediate superclass"
x := String allSuperclasses. "accumulated superclasses"
x := "receiver class and accumulated superclasses"
String withAllSuperclasses.
x := String subclasses. "immediate subclasses"
x := String allSubclasses. "accumulated subclasses"
x := String withAllSubclasses. "receiver class and accumulated subclasses"
b := String instSize. "number of named instance variables"
b := String isFixed. "true if no indexed instance variables"
b := String isIndexable "true if receiver has indexed instance variables"
b := String isVariable. "true if has indexed instance variables"
b := String isPointers. "true if index instance vars contain objects"
b := String isBits. "true if index instance vars contain bytes/words"
b := String isBytes. "true if index instance vars contain bytes"
b := String isWords. "true if index instance vars contain words"
Object withAllSubclasses size. "get total number of class entries"
"************************************************************************
* debuging: *
************************************************************************"
| a b x |
x yourself. "returns receiver"
String browse. "browse specified class"
x inspect. "open object inspector window"
x confirm: 'Is this correct?'.
x halt. "breakpoint to open debugger window"
x halt: 'Halt message'.
x notify: 'Notify text'.
x error: 'Error string'. "open up error window with title"
x doesNotUnderstand: #cmrMessage. "flag message is not handled"
x shouldNotImplement. "flag message should not be implemented"
x subclassResponsibility. "flag message as abstract"
x shouldNotImplement: #selector. "flag that #selector should not be implemented"
x subclassResponsibility: #selector. "flag that #selector as abstract"
x errorImproperStore. "flag an improper store into indexable object"
x errorNonIntegerIndex. "flag only integers should be used as index"
x errorSubscriptBounds. "flag subscript out of bounds"
x primitiveFailed. "system primitive failed"
a := 'A1'. b := 'B2'. a become: b. "switch two objects"
Transcript show: a, b; cr.
"************************************************************************
* Misc. *
************************************************************************"
| x |
Smalltalk condenseChanges. "compress the change file"
x := FillInTheBlank request: 'Prompt Me'. "prompt user for input"
Utilities openCommandKeyHelp