Useful API Functions

This document lists most useful (and most often needed) classes and functions. Be aware, that there are many more to be found in either the class references or via the builtin class browser.

String

All of the following operators are functional operators; meaning that they do not modify the argument(s).

Literals (i.e. Constant Strings)

'...'

Smalltalk style string (as is; no escapes for special characters). Be aware, that this is inconvenient, if newlines, tabs or other non-graphical characters are to be in the string.

c'...'

C style string (supports the usual C-escapes, such as "\n" for newline, "\t" for tab or "\xHH" for hex codes)

e'...{expr}...'

C style with embedded expressions. These are evaluated and sliced into the string.

Comparing

string1 = string2 => Boolean

compares case sensitive

string1 sameAs: string2 => Boolean

compares case insensitive

Case Conversion

aString asLowercase => String
aString asUppercase => String
aString asUppercaseFirst => String

return a case converted string

Finding Characters or Substrings

Finding Characters

aString indexOf: aCharacter => Integer

returns the 1-based index, or 0 if not found.
  Notice that character constants are denoted as $x in Smalltalk (or "Character return", "Character newline", "Character tab"...)

aString lastIndexOf: aCharacter => Integer

searching from the end, returns the 1-based index, or 0 if not found.

aString includes: aCharacter => Boolean

returns true if the character is included

Finding Strings

aString indexOfString: aSubString [ caseSensitive:boolean ] => Integer

returns the 1-based index, or 0 if not found.

aString includesString: aSubString [ caseSensitive:boolean ] => Boolean

returns true if the substring is included

aString startsWith: aSubString [ caseSensitive:boolean ] => Boolean

returns true if the substring is a prefix

aString endsWith: aSubString [ caseSensitive:boolean ] => Boolean

returns true if the substring is a prefix

Concatenation, Splitting and Joining

string1 , string2 (comma operator) => String

returns the concatenated string. (i.e. 'hello' , 'world' gives 'helloworld'.)

aString splitOn: aCharacter => CollectionOfStrings

splits the string into a collection of strings

aCollectionOfStrings join: separator => String

joins the string, inserting separator.

Reference: String inherits from: CharacterArray and SequenceableCollection and Collection

Collection

Reference: Collection

Filename

Reference: Filename

Stream

Streams can be internal (eg. reading from a String) or external (eg. a file stream, pipe or socket).

Reference: Stream

Number

Literals (i.e. Constant Numbers)

1234
16rFFAA or 0xaffe
2r0101 or 0b101010
NrXXX

integer constant; decimal, hex, binary or any base N; integers may be arbitrary long

0.5
1e5
-1.2e-3

float constant; actually double precision; use "q" for extra precision

(4/3)

a fraction (numerator / denominator)

(4+3i)

complex number (real part / imaginary part)

Arithmetic Operators

Notice: there are no precedence rules for binary operators ('+', '-', '*', etc.) in Smalltalk. All binary operators are evaluated left to right. Use parentheses to specify order.

number1 + number2 => Number
number1 - number2 => Number
number1 * number2 => Number
number1 / number2 => Number

any combination of types is possible (integer, float, fraction, complex)

number1 // number2 => Number

truncating division (truncates towards negative infinity; i.e. the next smaller number)

number1 \\ number2 => Number

remainder from above division

number1 quo: number2 => Number

truncating division (truncates towards zero; same as "//" for positive numbers)

number1 rem: number2 => Number

remainder from quo: (same as "\\" for positive numbers)

Math & Trigonometric Functions

aNumber ln => Number
aNumber log10 => Number
aNumber log2 => Number

logarithm; by default, an error is reported for negative numbers;
to get a complex result, use "Complex trapImaginary:[ aNumber ln ]".

aNumber sqrt => Number

square root; by default, an error is reported for negative numbers;
to get a complex result, use "Complex trapImaginary:[ aNumber sort ]".

aNumber cbrt => Number

cubic root.

aNumber exp => Number
number1 raisedTo: number2 => Number

exponentiation

aNumber sin => Number
aNumber cos => Number
aNumber tan => Number
aNumber arcSin => Number
aNumber arcCos => Number
aNumber arcTan => Number
aNumber arcTan2 => Number
aNumber sinh => Number
aNumber cosh => Number
aNumber tanh => Number

trigonometric / hyperbolic functions

Bitwise Operators

ínteger1 bitAnd: integer2 => Integer
ínteger1 bitOr: integer2 => Integer
ínteger1 bitXor: integer2 => Integer
ínteger1 bitShift: count => Integer
ínteger1 leftShift: count => Integer
ínteger1 rightShift: count => Integer
ínteger1 bitTest: integer2 => Boolean

bitwise operations

Reference: Number and its subclasses Integer, Float, Fraction, Complex

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