BEAMError

Inherits from Error

BEAMError — Foreign BEAM-specific exceptions.

Base class for exceptions that originate from BEAM-specific control flow mechanisms (exit and throw) that have no direct Beamtalk equivalent.

Standard Erlang error exceptions reuse existing Beamtalk classes (RuntimeError, TypeError). BEAMError is only for foreign concepts.

See: ADR 0028 §1 (Exception mapping)

Examples

[Erlang erlang exit: 1] on: BEAMError do: [:e | e message]

Inherited Methods

From Exception

message

Return the error message string.

Examples

[1 / 0] on: Exception do: [:e | e message]
hint

Return the actionable hint string, or nil if none.

Examples

[1 / 0] on: Exception do: [:e | e hint]
kind

Return the error kind as a symbol.

Examples

[1 / 0] on: Exception do: [:e | e kind]
selector

Return the message selector that triggered the error, or nil.

Examples

[42 unknownMsg] on: Exception do: [:e | e selector]
errorClass

Return the class name where the error occurred.

Examples

[42 unknownMsg] on: Exception do: [:e | e errorClass]
printString

Return a developer-readable string representation of the error.

Examples

[42 unknownMsg] on: Exception do: [:e | e printString]
stackTrace

Return the stack trace as a list of StackFrame objects.

Only available when the exception was caught via on:do:. Returns an empty list if no stacktrace was captured.

Examples

[1 / 0] on: Exception do: [:e | e stackTrace]
signal

Raise this exception.

Examples

(Exception new) signal
signal: msg

Raise this exception instance with the given message.

Examples

(Exception new) signal: "something went wrong"

From Object

class

Return the class of the receiver.

Examples

42 class              // => Integer
"hello" class         // => String
isNil

Test if the receiver is nil. Returns false for all objects except nil.

Examples

42 isNil              // => false
nil isNil             // => true
notNil

Test if the receiver is not nil. Returns true for all objects except nil.

Examples

42 notNil             // => true
nil notNil            // => false
ifNil: _nilBlock

If the receiver is nil, evaluate nilBlock. Otherwise return self.

Examples

42 ifNil: [0]         // => 42
nil ifNil: [0]        // => 0
ifNotNil: notNilBlock

If the receiver is not nil, evaluate notNilBlock with self.

Examples

42 ifNotNil: [:v | v + 1]   // => 43
nil ifNotNil: [:v | v + 1]  // => nil
ifNil: _nilBlock ifNotNil: notNilBlock

If nil, evaluate nilBlock; otherwise evaluate notNilBlock with self.

Examples

42 ifNil: [0] ifNotNil: [:v | v + 1]    // => 43
nil ifNil: [0] ifNotNil: [:v | v + 1]   // => 0
ifNotNil: notNilBlock ifNil: _nilBlock

If not nil, evaluate notNilBlock with self; otherwise evaluate nilBlock.

Examples

42 ifNotNil: [:v | v + 1] ifNil: [0]    // => 43
nil ifNotNil: [:v | v + 1] ifNil: [0]   // => 0
printString

Return a developer-readable string representation.

Default implementation returns "a ClassName". Subclasses such as Integer, String, and List override this to return richer output.

Examples

42 printString            // => "42"
displayString

Return a user-facing string representation for display purposes.

Default implementation delegates to printString. Subclasses such as String and Symbol override this to return a more readable form without developer annotations (e.g. no surrounding quotes or # prefix).

Examples

42 displayString             // => "42"
inspect

Inspect the receiver.

Examples

42 inspect             // => "42"
yourself Sealed

Return the receiver itself. Useful for cascading side effects.

Examples

42 yourself            // => 42
hash

Return a hash value for the receiver.

Examples

42 hash
respondsTo: selector Sealed

Test if the receiver responds to the given selector.

Examples

42 respondsTo: #abs    // => true
fieldNames Sealed

Return the names of fields.

Examples

42 fieldNames             // => #()
fieldAt: name Sealed

Return the value of the named field.

Examples

object fieldAt: #name
fieldAt: name put: value Sealed

Set the value of the named field (returns new state).

Examples

object fieldAt: #name put: "Alice"
perform: selector Sealed

Send a unary message dynamically.

Examples

42 perform: #abs       // => 42
perform: selector withArguments: args Sealed

Send a message dynamically with arguments.

Examples

3 perform: #max: withArguments: #(5)   // => 5
subclassResponsibility

Raise an error indicating this method must be overridden by a subclass.

Examples

self subclassResponsibility
notImplemented

Raise an error indicating this method has not yet been implemented.

Use this for work-in-progress stubs. Distinct from subclassResponsibility, which signals an interface contract violation.

Examples

self notImplemented
show: aValue

Send aValue to the current transcript without a trailing newline.

Nil-safe: does nothing when no transcript is set (batch compile, tests).

Examples

42 show: "value: "
showCr: aValue

Send aValue to the current transcript followed by a newline.

Nil-safe: does nothing when no transcript is set (batch compile, tests).

Examples

42 showCr: "hello world"
isKindOf: aClass

Test if the receiver is an instance of aClass or any of its subclasses.

Examples

42 isKindOf: Integer    // => true
42 isKindOf: Object     // => true
#foo isKindOf: Symbol   // => true
#foo isKindOf: String   // => false
error: message

Raise an error with the given message.

Examples

self error: "something went wrong"

From ProtoObject

== other

Test value equality (Erlang ==).

Examples

42 == 42           // => true
"abc" == "abc"     // => true
/= other

Test value inequality (negation of ==).

Examples

1 /= 2             // => true
42 /= 42           // => false
class

Return the class of the receiver.

Examples

42 class            // => Integer
"hello" class       // => String
doesNotUnderstand: selector args: arguments

Handle messages the receiver does not understand. Override for custom dispatch.

Examples

42 unknownMessage   // => ERROR: does_not_understand
perform: selector withArguments: arguments

Send a message dynamically with an arguments list.

Examples

42 perform: #abs withArguments: #()   // => 42
performLocally: selector withArguments: arguments

Execute a class method in the caller's process, bypassing gen_server dispatch.

The caller takes responsibility for knowing the method does not mutate class state. Useful for long-running class methods that would otherwise block the class object's gen_server.

Limitations: only resolves methods defined directly on the target class module (does not walk the superclass chain). Class variables and self are not available to the method (nil and #{} are passed).

Examples

MyClass performLocally: #run:ctx: withArguments: #(input, ctx)
perform: selector withArguments: arguments timeout: timeoutMs

Send a message dynamically with an arguments list and explicit timeout.

The timeout (in milliseconds or #infinity) applies to the gen_server:call when the receiver is an actor. For value types, timeout is ignored.

Examples

actor perform: #query withArguments: #(sql) timeout: 30000