Edit

BRL.Blitz

The Blitz runtime module provides low level functionality required by BlitzMax applications when they are running. This includes things like memory management, exception handling and string and array operations.

Much of the functionality provided by this module is hidden from application programmers, but is instead used 'behind the scenes' by the compiler. However, there are some very useful commands for debugging, memory management and simple standard IO.

Types

Type	Description
TBlitzException	Exception
TNullObjectException	Null object exception
TNullMethodException	Null method exception
TNullFunctionException	Null function exception
TArrayBoundsException	Array bounds exception
TOutOfDataException	Out of data exception
TRuntimeException	Runtime exception
TInvalidEnumException	Invalid enum exception

Interfaces

Interface	Description
IDisposable	Provides a mechanism for releasing resources.

Functions

Function Max:Int(a:Int, b:Int) Inline

Returns the larger of the two Int arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:Long(a:Long, b:Long) Inline

Returns the larger of the two Long arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:Float(a:Float, b:Float) Inline

Returns the larger of the two Float arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:Double(a:Double, b:Double) Inline

Returns the larger of the two Double arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:Byte(a:Byte, b:Byte) Inline

Returns the larger of the two Byte arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:Short(a:Short, b:Short) Inline

Returns the larger of the two Short arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:UInt(a:UInt, b:UInt) Inline

Returns the larger of the two UInt arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:ULong(a:ULong, b:ULong) Inline

Returns the larger of the two ULong arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Max:Size_T(a:Size_T, b:Size_T) Inline

Returns the larger of the two Size_T arguments.

Example

Rem
Max
Max evaluates to the value of the largest of the two operators.
End Rem

SuperStrict

Print Max(10,20)    '20
Print Max(20,10)    '20

Function Min:Int(a:Int, b:Int) Inline

Returns the lesser of the two Int arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:Long(a:Long, b:Long) Inline

Returns the lesser of the two Long arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:Float(a:Float, b:Float) Inline

Returns the lesser of the two Float arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:Double(a:Double, b:Double) Inline

Returns the lesser of the two Double arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:Byte(a:Byte, b:Byte) Inline

Returns the lesser of the two Byte arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:Short(a:Short, b:Short) Inline

Returns the lesser of the two Short arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:UInt(a:UInt, b:UInt) Inline

Returns the lesser of the two UInt arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:ULong(a:ULong, b:ULong) Inline

Returns the lesser of the two ULong arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Min:Size_T(a:Size_T, b:Size_T) Inline

Returns the lesser of the two Size_T arguments.

Example

Rem
Min evaluates to the value of the smallest of the two operators.
End Rem

SuperStrict

Print Min(10,20)    '10
Print Min(20,10)    '10

Function Abs:Int(a:Int) Inline

Returns the absolute value of the Int argument.

Example

Rem
Abs is a mathematical operator that performs the Absolute function.
End Rem

SuperStrict

For Local f:Float = -1 To 1 Step 0.125
    Print "Abs "+f+"="+Abs f
Next

Function Abs:Float(a:Float) Inline

Returns the absolute value of the Float argument.

Example

Rem
Abs is a mathematical operator that performs the Absolute function.
End Rem

SuperStrict

For Local f:Float = -1 To 1 Step 0.125
    Print "Abs "+f+"="+Abs f
Next

Function Abs:Double(a:Double) Inline

Returns the absolute value of the Double argument.

Example

Rem
Abs is a mathematical operator that performs the Absolute function.
End Rem

SuperStrict

For Local f:Float = -1 To 1 Step 0.125
    Print "Abs "+f+"="+Abs f
Next

Function Abs:Long(a:Long) Inline

Returns the absolute value of the Long argument.

Example

Rem
Abs is a mathematical operator that performs the Absolute function.
End Rem

SuperStrict

For Local f:Float = -1 To 1 Step 0.125
    Print "Abs "+f+"="+Abs f
Next

Function Sgn:Int(a:Int) Inline

Returns the sign of the Int argument.

Example

Rem
Sgn is a mathematical operator that returns the sign of a value.
End Rem

SuperStrict

Print Sgn 50    '1
Print Sgn 0     '0
Print Sgn -50   '-1

Function Sgn:Float(a:Float) Inline

Returns the sign of the Float argument.

Example

Rem
Sgn is a mathematical operator that returns the sign of a value.
End Rem

SuperStrict

Print Sgn 50    '1
Print Sgn 0     '0
Print Sgn -50   '-1

Function Sgn:Double(a:Double) Inline

Returns the sign of the Double argument.

Example

Rem
Sgn is a mathematical operator that returns the sign of a value.
End Rem

SuperStrict

Print Sgn 50    '1
Print Sgn 0     '0
Print Sgn -50   '-1

Function Sgn:Long(a:Long) Inline

Returns the sign of the Long argument.

Example

Rem
Sgn is a mathematical operator that returns the sign of a value.
End Rem

SuperStrict

Print Sgn 50    '1
Print Sgn 0     '0
Print Sgn -50   '-1

Function RuntimeError( message$ )

Generate a runtime error

Throws a TRuntimeException.

Example

' runtimeerror.bmx

SuperStrict

Local a:Int

If a=0 RuntimeError "This program has failed badly."

Function DebugStop()

Stop program execution and enter debugger

If there is no debugger present, this command is ignored.

Example

'
' Run in debug mode
'
SuperStrict

Graphics 640,480
Local a:Int

Repeat
    a = Rnd(20)
Until KeyDown(KEY_ESCAPE)
DebugStop

Function DebugLog( message$ )

Write a string to debug log

If there is no debugger present, this command is ignored.

Example

'
' Run in debug mode to see the output
'
SuperStrict

DebugLog "My debug text"

Function OnEnd( fun() )

Add a function to be called when the program ends

OnEnd allows you to specify a function to be called when the program ends. OnEnd functions are called in the reverse order to that in which they were added.

Example

' onend.bmx

SuperStrict

Function cleanup()
    Print "cleaning up"
End Function

OnEnd cleanup
Print "program running"
End 'the cleanup function will be called at this time

Function ReadStdin$()

Read a string from stdin

Returns

A string read from stdin. The newline terminator, if any, is included in the returned string.

Function WriteStdout( str$ )

Write a string to stdout

Writes str to stdout and flushes stdout.

Function WriteStderr( str$ )

Write a string to stderr

Writes str to stderr and flushes stderr.

Function Delay( millis:Int )

Wait for a given number of milliseconds

Delay suspends program execution for at least millis milliseconds.

A millisecond is one thousandth of a second.

Example

SuperStrict

Print "This is a test line."

Delay 3000

Print "This line was printed 3000 milliseconds later."
Print "This program will end in 2000 milliseconds."

Delay 2000

Function UDelay( microseconds:Int )

Wait for a given number of microseconds

UDelay suspends program execution for at least microcseconds.

A microsecond is one millionth of a second.

Function MilliSecs:Int()

Get millisecond counter

MilliSecs returns the number of milliseconds elapsed since the computer was turned on.

A millisecond is one thousandth of a second.

Returns

Milliseconds since computer turned on.

Example

SuperStrict

Local start:Int = MilliSecs()

Input("Type Anything >")

Print "You took "+(MilliSecs()-start)+" milliseconds to type that."

Function MemAlloc:Byte Ptr( size:Size_T )

Allocate memory

Returns

A new block of memory size bytes long

Function MemFree( mem:Byte Ptr )

Free allocated memory

The memory specified by mem must have been previously allocated by MemAlloc or MemExtend.

Function MemExtend:Byte Ptr( mem:Byte Ptr,size:Size_T,new_size:Size_T )

Extend a block of memory

An existing block of memory specified by mem and size is copied into a new block of memory new_size bytes long. The existing block is released and the new block is returned.

Returns

A new block of memory new_size bytes long

Function MemClear( mem:Byte Ptr,size:Size_T )

Clear a block of memory to 0

Function MemCopy( dst:Byte Ptr,src:Byte Ptr,size:Size_T )

Copy a non-overlapping block of memory

Function MemMove( dst:Byte Ptr,src:Byte Ptr,size:Size_T )

Copy a potentially overlapping block of memory

Function GCSetMode( Mode:Int )

Set garbage collector mode

mode can be one of the following:
1 : automatic GC - memory will be automatically garbage collected
2 : manual GC - no memory will be collected until a call to GCCollect is made

The default GC mode is automatic GC.

Function GCSuspend()

Suspend garbage collector

GCSuspend temporarily suspends the garbage collector. No garbage collection will be performed following a call to GCSuspend.

Use GCResume to resume the garbage collector. Note that GCSuspend and GCResume 'nest', meaning that each call to GCSuspend must be matched by a call to GCResume.

Function GCResume()

Resume garbage collector

GCResume resumes garbage collection following a call to GCSuspend.

See GCSuspend for more details.

Function GCCollect:Size_T()

Run garbage collector

This function will have no effect if the garbage collector has been suspended due to GCSuspend.

Returns

The amount of memory, in bytes, collected.

Function GCCollectALittle:Int()

Run garbage collector, collecting a little

This function will have no effect if the garbage collector has been suspended due to GCSuspend.

Returns

Returns 0 if there is no more to collect.

Function GCMemAlloced:Size_T()

Memory allocated by application

This function only returns 'managed memory'. This includes all objects, strings and arrays in use by the application.

Returns

The amount of memory, in bytes, currently allocated by the application

Function GCEnter()

Private: do not use

Function GCLeave()

Private: do not use

Function GCRetain(obj:Object)

Retains a reference to the specified Object, preventing it from being collected.

Function GCRelease(obj:Object)

Releases a reference from the specified Object.

Function GCThreadIsRegistered:Int()

Returns True if the current thread is registered with the garbage collector.

Function GCRegisterMyThread:Int()

Registers the current thread with the garbage collector.

Returns

0 on success, 1 if the thread was already registered, or -1 if threads are not supported.

Function GCUnregisterMyThread:Int()

Unregisters the previously registered current thread.

Note, that any memory allocated by the garbage collector from the current thread will no longer be accessible after the thread is unregistered.

Function HandleFromObject:Size_T( obj:Object )

Convert object to integer handle

After converting an object to an integer handle, you must later release it using the Release command.

Returns

An integer object handle

Function HandleToObject:Object( handle:Size_T )

Convert integer handle to object

Returns

The object associated with the integer handle

Function ArrayCopy(src:Object, srcPos:Int, dst:Object, dstPos:Int, length:Int)

Copies an array from the specified src array, starting at the position srcPos, to the position dstPos of the destination array.

Function IsEmptyArray:Int(obj:Object)

Determines whether the Object obj is an empty array.

Returns

True if obj is an empty array, or False otherwise.

Function IsEmptyString:Int(obj:Object)

Determines whether the Object obj is an empty String.

Returns

True if obj is an empty String, or False otherwise.

Function ObjectIsString:Int(obj:Object)

Determines whether the Object obj is a String.

Returns

True if obj is a String, or False otherwise.

Globals

Global AppDir$="bbAppDir"

Application directory

The AppDir global variable contains the fully qualified directory of the currently executing application. An application's initial current directory is also set to AppDir when an application starts.

In a compiled DLL, the AppDir global variable will instead contain the fully qualified directory of the DLL.

Example

' appdir.bmx
' requests the user to select a file from the application's directory

SuperStrict

Print "Application Directory="+AppDir

Local file:String = RequestFile("Select File to Open","",False,AppDir)

Print "file selected was :"+file

Global AppFile$="bbAppFile"

Application file name

The AppFile global variable contains the fully qualified file name of the currently executing application.

In a compiled DLL, the AppFile global variable will instead contain the fully qualified file name of the DLL.

Example

' appfile.bmx

SuperStrict

Print "This program's executable is located at "+AppFile

Global AppTitle$="bbAppTitle"

Application title

The AppTitle global variable is used by various commands when a default application title is required - for example, when opening simple windows or requesters.

Initially, AppTitle is set to the value "BlitzMax Application". However, you may change AppTitle at any time with a simple assignment.

Example

'Apptitle Example

SuperStrict

AppTitle = "Just a TITLE"
Graphics 400, 400

Repeat
    DrawText "Hello World", 10, 20
    Flip
Until AppTerminate()

Global AppArgs$[]="bbAppArgs"

Arguments passed to the application at startup

The AppArgs global array contains the command line parameters sent to an application when it was started. The first element of AppArgs always contains the name of the application. However, the format of the name may change depending on how the application was launched. Use AppDir or AppFile for consistent information about the applications name or directory.

Example

' appargs.bmx
' print the command line arguments passed to the program at runtime

SuperStrict

Print "Number of arguments = "+AppArgs.length

For Local a:String = EachIn AppArgs
    Print a
Next

Global LaunchDir$="bbLaunchDir"

Directory from which application was launched

The LaunchDir global variable contains the current directory at the time the application was launched. This is mostly of use to command line tools which may need to access the 'shell' current directory as opposed to the application directory.

Example

' launchdir.bmx

SuperStrict

Print "This program was launched from "+LaunchDir$

Keywords

Strict

Set strict mode

See the BlitzMax Language Reference for more information on Strict mode programming.

Example

Rem
Strict advises the BlitzMax compiler to report as errors all auto defined variables.
End Rem

Strict

local a=10

b=20    'compiler error, strict mode means variables must be declared b4 use

SuperStrict

Set SuperStrict mode

End

End program execution

Example

Rem
The End command causes a program to exit immediately.
End Rem

SuperStrict

Print "Hello!"
End
Print "This line will never be printed as the program has already been ended."

Rem

Begin a remark block

Example

Rem

My Rem Example
First created 9th August, 2004

(C)2050 Blitz Intergalactic Software Corporation

End Rem

SuperStrict

Print "This program has no useful function"

Rem

Remarks are useful for making your program easily readable.
You can leave details explaining the function of your program
in a remarks section so that you and any other programmers
that work with your code can more easily understand the workings
of your program

End Rem

Print "Sorry."
End

EndRem

End a remark block

Example

Rem
All code between Rem and EndRem is ignored by the BlitzMax compiler.
Print "hello"
End Rem

SuperStrict

Print "goodbye"

True

Constant integer of value 1

Example

Rem
True is a Constant Integer assigned the value 1.
End Rem

SuperStrict

Print "True="+True

If True
    Print "This line will always be executed"
EndIf

If Not True
    Print "This line will never be executed"
EndIf

False

Constant integer of value 0

Example

Rem
False is a Constant Integer assigned the value 0.
End Rem

SuperStrict

Print "False="+False

If False
    Print "This code will never be executed"
EndIf

Pi

Constant pi value: 3.1415926535897932384626433832795

Example

Rem
Pi is a Constant Double assigned the value 3.1415926535897932384626433832795
End Rem

SuperStrict

Print "Pi="+Pi

Null

Get Null value (default value for types)

Example

Rem
Null is a BlitzMax Constant representing an empty Object reference.
End Rem

SuperStrict

Type mytype
    Field atypevariable:Int
End Type

Global a:mytype

If a=Null Print "a is uninitialized"
a=New mytype
If a<>Null Print "a is initialized"

Byte

Unsigned 8 bit integer type

Example

Rem
Byte is an unsigned 8 bit integer BlitzMax primitive type.
End Rem

SuperStrict

Local a:Byte

a=512;Print "a="+a  'prints 0
a=-1;Print "a="+a   'prints 255

Short

Unsigned 16 bit integer type

Example

Rem
Short is an unsigned 16 bit integer BlitzMax primitive type.
End Rem

SuperStrict

Local a:Short

a=65536;Print "a="+a    'prints 0
a=-1;Print "a="+a   'prints 65535

Int

Signed 32 bit integer type

Example

Rem
Int is a signed 32 bit integer BlitzMax primitive type.
End Rem

SuperStrict

Local a:Int

' the following values all print 0 as BlitzMax "rounds to zero"
' when converting from floating point to integer

a=0.1;Print a
a=0.9;Print a
a=-0.1;Print a
a=-0.9;Print a

UInt

Unsigned 32 bit integer type

Long

Signed 64 bit integer type

Example

Rem
Long is a signed 64 bit integer BlitzMax primitive type.
End Rem

SuperStrict

Const MAXLONG:Long=$7fffffffffffffff:Long
Const MINLONG:Long=$8000000000000000:Long

Print "A long can have the maximum value of:"+MAXLONG
Print "A long can have the minimum value of:"+MINLONG

ULong

Unsigned 64 bit integer type

Size_T

Unsigned 32/64 bit integer type

LParam

Signed 32/64 bit LPARAM WinAPI type

Only available on Windows.

WParam

Unsigned 32/64 bit WPARAM WinAPI type

Only available on Windows.

Float

32 bit floating point type

Example

Rem
Float is a 32 bit floating point BlitzMax primitive type.
End Rem

SuperStrict

Local a:Float

a=1

For Local i:Int = 1 To 8
    Print a
    a=a*0.1
Next

For Local i:Int = 1 To 8
    a=a*10
    Print a
Next

Double

64 bit floating point type

Example

Rem
Double is a 64 bit floating point BlitzMax primitive type.
End Rem

SuperStrict

Local speedoflight:Double
Local distance:Double
Local seconds:Double

speedoflight=299792458:Double   'meters per second
distance=149597890000:Double    'average distance in meters from earth sun

seconds=distance/speedoflight

Print "Number of seconds for light to travel from earth to sun="+seconds

Int128

128 bit integer intrinsic type

Only available on x64.

Float64

64 bit floating point intrinsic type

Only available on x64.

Float128

128 bit floating point intrinsic type

Only available on x64.

Double128

128 bit floating point intrinsic type

Only available on x64.

String

String type

Example

Rem
String is a BlitzMax container type containing a sequence of unicode characters.
End Rem

SuperStrict

Local quote:String=Chr(34)
Print quote+"Hello World!"+quote

Object

Object type

Example

Rem
Object is the base class of all BlitzMax types.

The following function attempts to cast from any object to
the custom type TImage and returns true if the given object
is an instance of TImage or an instance of a &Type derived
from TImage.
End Rem

SuperStrict

Function IsImage(obj:Object)
    If TImage(obj) Return True
    Return False
End Function

Var

Composite type specifier for 'by reference' types

Example

Rem
Var is a composite type containing a reference to a variable of the 
specified Type.
End Rem

SuperStrict

' the following illustrates parsing function parameters by reference

Function ReturnMultiplevalues(a:Int Var,b:Int Var,c:Int Var)
    a=10
    b=20
    c=30
    Return
End Function

Local x:Int,y:Int,z:Int

ReturnMultipleValues(x,y,z)

Print "x="+x    '10
Print "y="+y    '20
Print "z="+z    '30

Ptr

Composite type specifier for pointer types

Example

Rem
Ptr is a composite type containing a pointer to a variable of the specified Type.
End Rem

' the following illustrates the use of traditional c style pointers

SuperStrict

Local c:Int[]=[1,2,3,4]
Local p:Int Ptr

p=c
Print "pointer 'p' points to:"+p[0] '1

p:+1
Print "pointer 'p' points to:"+p[0] '2

p:+1
Print "pointer 'p' points to:"+p[0] '3

p:+1
Print "pointer 'p' points to:"+p[0] '4

If

Begin a conditional block.

Example

Rem
If begins a conditional block.
End Rem

SuperStrict

If 3<5 Print "3<5"  'single line if

If 5<7              'if block
    Print "5<7"
EndIf

Then

Optional separator between the condition and associated code in an If statement.

Example

Rem
Then is an optional separator between the condition and the block of code following an If statement.
End Rem

SuperStrict

If 3<5 Then Print "3<5"

Else

Else provides the ability for an If-Then construct to execute a second block of code when the If condition is false.

Example

Rem
Else provides the ability for an If Then construct to execute a second block of code when the If condition is false.
End Rem

SuperStrict

Local i:Int = 3

If i<5 Print "i<5" Else Print "i>=5"    ' single line If Else

If i<5          'block style If Else
    Print "i<5"
Else
    Print "i>=5"
EndIf

ElseIf

ElseIf provides the ability to test and execute a section of code if the initial condition failed.

Example

Rem
ElseIf provides the ability to test and execute a section of code if the initial condition failed.
End Rem

SuperStrict

Local age:Int = Int( Input("How old Are You?") )

If age<13
    Print "You are young"
ElseIf age<20
    Print "You are a teen!"
Else
    Print "You are neither young nor a teen"
EndIf

EndIf

Marks the End of an If-Then construct.

Example

Rem
EndIf marks the end of an If Then block.
End Rem

SuperStrict

Local i:Int = 5

If i<10
    Print "i<10"
EndIf

For

Marks the start of a loop that uses an iterator to execute a section of code repeatedly.

Example

Rem
For marks the start of a loop that uses an iterator to execute a section of code repeatedly.
End Rem

' print 5 times table

SuperStrict

For Local i:Int = 1 To 12
    Print "5*"+i+"="+5*i
Next

To

Followed by a constant which is used to calculate when to exit a For..Next loop.

Example

Rem
Followed by a constant which is used to calculate when to exit a For..Next loop.
End Rem

SuperStrict

For Local i:Int = 1 To 5
    Print i
Next

Step

Specifies an optional constant that is used to increment the For iterator.

Example

Rem
Specifies an optional constant that is used to increment the For iterator.
End Rem

' count backwards from 10 to 0

SuperStrict

For Local i:Int = 10 To 0 Step -1
    Print i
Next

Next

End a For block

Example

Rem
Marks the end of a For section.
End Rem

SuperStrict

For Local i:Int = 1 To 5
    Print i
Next

EachIn

Iterate through an array or collection

Example

Rem
Specifies a BlitzMax collection type whose values are assigned sequentially to the For iterator.
End Rem

SuperStrict

Local a:Int[]=[0,5,12,13,20]

For Local b:Int = EachIn a
    Print b
Next

While

Execute a block of code while a condition is true

Example

Rem
While executes the following section of code repeatedly while a given condition is true.
End Rem

SuperStrict

Graphics 640,480
While Not KeyHit(KEY_ESCAPE)    'loop until escape key is pressed
    Cls
    For Local i:Int = 1 To 200
        DrawLine Rnd(640),Rnd(480),Rnd(640),Rnd(480)
    Next
    Flip
Wend

Wend

End a While block

Example

Rem
Wend marks the end of a While section.
End Rem

SuperStrict

Local i:Int

While i<5
    Print i
    i:+1
Wend

EndWhile

End a While block

Example

SuperStrict

Local i:Int=0

While i < 5
  Print i
  i :+ 1
EndWhile  'can also use Wend

Repeat

Execute a block of code until a termination condition is met, or forever

Example

Rem
Repeat executes the following section of code until a terminating condition is true.
End Rem

SuperStrict

Local i:Int

Repeat
    Print i
    i:+1
Until i=5

Until

Conditionally continue a Repeat block

Example

Rem
Until marks the end of a Repeat block and is followed by a terminating condition.
End Rem

SuperStrict

Local i:Int = 2
Repeat
    Print i
    i:*2
Until i>1000000

Forever

Continue a Repeat block forever

Example

Rem
Forever is an alternate ending to a Repeat block that will cause the loop to always repeat.
End Rem

SuperStrict

Local i:Int
Repeat
    Print i+" Ctrl-C to End!" 
    i:+1
Forever

Select

Begin a Select block

Example

Rem
Select begins a block featuring a sequence of multiple comparisons with a single value.
End Rem

SuperStrict

Local a:Int = Int( Input("Enter Your Country Code ") )

Select a
    Case 1
        Print "You are from America"
    Case 44
        Print "You are from the United Kingdom"
    Case 62
        Print "You are from Australia"
    Case 64
        Print "You are from New Zealand"
    Default
        Print "I cannot tell which country you are from"
End Select

EndSelect

End a Select block

Example

Rem
EndSelect marks the end of a Select block.
End Rem

SuperStrict
SeedRnd MilliSecs()

Local a:Int = Rand(5)

Select a
    Case 1 Print "one"
    Case 2 Print "two"
    Case 3 Print "three"
    Case 4 Print "four"
    Case 5 Print "five"
    Default Print "Program Error"
End Select

Case

Conditional code inside a Select block

Example

' case.bmx

' Case performs a comparison with the preceeding value(s) and that
' listed in the enclosing Select statement:

SuperStrict

Local a:Int=Int( Input("Enter a number between 1 and 5 ") )

Select a
    Case 1 Print "You think small"
    Case 2 Print "You are even tempered"
    Case 3,4 Print "You are middle of the road" 
    Case 5 Print "You think big"
    Default Print "You are unable to follow instructions"
End Select

Default

Default code inside a Select block

Example

Rem
Default is used in a Select block to mark a code section that is executed if all prior Case statements fail.
End Rem

SuperStrict

Local a:String = Input("What is your favorite color?")
a=Lower(a)  'make sure the answer is lower case

Select a
    Case "yellow" Print "You a bright and breezy"
    Case "blue" Print "You are a typical boy"
    Case "pink" Print "You are a typical girl"
    Default Print "You are quite unique!"
End Select

Exit

Exit enclosing loop

Example

Rem
Exit causes program flow to exit the enclosing While, Repeat or For loop.
End Rem

SuperStrict

Local n:Int
Repeat
    Print n
    n:+1
    If n=5 Exit
Forever

Continue

Continue execution of enclosing loop

Example

Rem
Continue causes program flow to return to the start of the enclosing While, Repeat or For program loop
End Rem

SuperStrict

For Local i:Int = 1 To 20
    If i Mod 2 Continue
    Print i
Next

Const

Declare a constant

Example

Rem
Const defines the preceeding variable declaration as constant.
End Rem

SuperStrict

Const ON:Int=True
Const OFF:Int=False

Const TWOPI:Float=2*Pi

Print TWOPI

Local

Declare a local variable

Example

Rem
Local defines a variable as local to the Method or Function it is defined meaning it is automatically released when the function returns.
End Rem

SuperStrict

Function TestLocal()
    Local a:Int
    a=20
    Print "a="+a
    Return
End Function

TestLocal
Print "a="+a    'prints an error as a is only local to the TestLocal function

Global

Declare a global variable

Example

Rem
Global defines a variable as Global allowing it be accessed from within Methods and Functions.
End Rem

SuperStrict

Global a:Int = 20

Function TestGlobal()
    Print "a="+a
End Function

TestGlobal
Print "a="+a

Field

Declare a field variable

Example

Rem
Field is used to declare the member variable(s) of a type.
End Rem

SuperStrict

Type TVector
    Field   x:Int,y:Int,z:Int
End Type

Local a:TVector=New TVector

a.x=10
a.y=20
a.z=30

Function

Begin a function declaration

Example

Rem
Function marks the beginning of a BlitzMax function declaration.

When a function does not return a value the use of brackets when
calling the function is optional.
End Rem

SuperStrict

Function NextArg(a:String)
    Local p:Int
    p=Instr(a,",")
    If p 
        NextArg a[p..]
        Print a[..p-1]
    Else
        Print a
    EndIf
End Function

NextArg("one,two,three,four")

NextArg "22,25,20"  'look ma, no brackets

EndFunction

End a function declaration

Example

Rem
Function marks the end of a BlitzMax function declaration.
End Rem

SuperStrict

Function RandomName$()
    Local a$[]=["Bob","Joe","Bill"]
    Return a[Rnd(Len a)]
End Function

For Local i:Int = 1 To 5
    Print RandomName$()
Next

Method

Begin a method declaration

Example

Rem
Method marks the beginning of a BlitzMax custom type member function.
End Rem

SuperStrict

Type TPoint
    Field x:Int,y:Int

    Method ToString:String()
        Return x+","+y
    End Method
End Type

Local a:TPoint=New TPoint
Print a.ToString()

EndMethod

End a method declaration

Example

Rem
EndMethod marks the end of a BlitzMax Method declaration.
End Rem

SuperStrict

Type TPoint
    Field x:Int,y:Int

    Method ToString:String()
        Return x+","+y
    End Method
End Type

Local p:TPoint = New TPoint
Print p.ToString()

Return

Return from a method or function

Example

Rem
Return exits a BlitzMax function or method with an optional value.
The type of return value is dictated by the type of the function.
End Rem

SuperStrict

Function CrossProduct#(x0#,y0#,z0#,x1#,y1#,z1#)
    Return x0*x1+y0*y1+z0*z1
End Function

Print "(0,1,2)x(2,3,4)="+CrossProduct(0,1,2,2,3,4)

Function LongRand:Long()
    Return (Rand($80000000,$7fffffff) Shl 32)|(Rand($80000000,$7fffffff))
End Function

Print "LongRand()="+LongRand()
Print "LongRand()="+LongRand()

Type

Begin a user defined class declaration

Example

Rem
Type marks the beginning of a BlitzMax custom type.

Standard BlitzMax types use a preceeding "T" naming
convention to differentiate themselves from standard
BlitzMax variable names.
End Rem

SuperStrict

Type TVector
    Field x:Int,y:Int,z:Int
End Type

Local a:TVector=New TVector

a.x=10
a.y=20
a.z=30

EndType

End a user defined class declaration

Example

Rem
EndType marks the end of a BlitzMax custom type.
End Rem

SuperStrict

Type TVector
    Field x:Int,y:Int,z:Int
End Type

Local a:TVector=New TVector

a.x=10
a.y=20
a.z=30

Interface

Begin a user defined interface declaration

EndInterface

End a user defined interface declaration

Struct

Begin a user defined structure declaration

EndStruct

End a user defined structure declaration

Enum

Begin an enumeration declaration

EndEnum

End an enumeration declaration

Extends

Specify supertype(s) of a user defined type

Example

Rem
Extends is used in a BlitzMax Type declaration to derive the Type from a specified base class.
End Rem

SuperStrict

Type TShape
    Field xpos:Int,ypos:Int
    Method Draw() Abstract
End Type

Type TCircle Extends TShape
    Field radius:Int
    
    Function Create:TCircle(x:Int,y:Int,r:Int)
        Local c:TCircle=New TCircle
        c.xpos=x;c.ypos=y;c.radius=r
        Return c
    End Function
    
    Method Draw()
        DrawOval xpos,ypos,radius,radius
    End Method
End Type

Type TRect Extends TShape
    Field width:Int,height:Int
    
    Function Create:TRect(x:Int,y:Int,w:Int,h:Int)
        Local r:TRect=New TRect
        r.xpos=x;r.ypos=y;r.width=w;r.height=h
        Return r
    End Function
    
    Method Draw()
        DrawRect xpos,ypos,width,height
    End Method
End Type

Local shapelist:TShape[4]
Local shape:TShape

shapelist[0]=TCircle.Create(200,50,50)
shapelist[1]=TRect.Create(300,50,40,40)
shapelist[2]=TCircle.Create(400,50,50)
shapelist[3]=TRect.Create(200,180,250,20)

Graphics 640,480
While Not KeyHit(KEY_ESCAPE)
    Cls
    For shape=EachIn shapelist
        shape.draw
    Next
    Flip
Wend
End

Implements

Specify implemented interface(s) of a user defined type

Abstract

Denote a class, function or method as abstract

Example

Rem
A BlitzMax type that contains Abstract methods becomes abstract itself.
Abstract types are used to define interfaces that extending types must 
implement before they can be used to create new instances.

In the following code TShape is an abstract type in that you can not
create a TShape but anything extending a TShape must implement a Draw()
method.
End Rem

SuperStrict

Type TShape
    Field xpos:Int,ypos:Int
    Method Draw() Abstract
End Type

Type TCircle Extends TShape
    Field radius:Int
    
    Function Create:TCircle(x:Int,y:Int,r:Int)
        Local c:TCircle = New TCircle
        c.xpos=x;c.ypos=y;c.radius=r
        Return c
    End Function
    
    Method Draw()
        DrawOval xpos,ypos,radius,radius
    End Method
End Type

Type TRect Extends TShape
    Field width:Int,height:Int
    
    Function Create:TRect(x:Int,y:Int,w:Int,h:Int)
        Local r:TRect = New TRect
        r.xpos=x;r.ypos=y;r.width=w;r.height=h
        Return r
    End Function
    
    Method Draw()
        DrawRect xpos,ypos,width,height
    End Method
End Type

Local shapelist:TShape[4]
Local shape:TShape

shapelist[0]=TCircle.Create(200,50,50)
shapelist[1]=TRect.Create(300,50,40,40)
shapelist[2]=TCircle.Create(400,50,50)
shapelist[3]=TRect.Create(200,180,250,20)

Graphics 640,480
While Not KeyHit(KEY_ESCAPE)
    Cls
    For shape=EachIn shapelist
        shape.draw
    Next
    Flip
Wend
End

Final

Denote a class, function or method as final

Example

Rem
Final stops methods from being redefined in super classes.
End Rem

SuperStrict

Type T1
    Method ToString:String() Final
        Return "T1"
    End Method
End Type

Type T2 Extends T1
    Method ToString:String()    'compile time error "Final methods cannot be overridden"
        Return "T2"
    End Method
End Type

ReadOnly

Denote a field as read only, where the value may only be set in its declaration or in the type constructor

Export

Denote a function for export to a shared library. The generated function name will not be mangled.

Override

Indicates that a method declaration is intended to override a method declaration in a supertype.

Use of Override on a method that does not override a method will result in a compilation error.

Where

Specify constraints on the types that can be used as arguments for a type parameter defined in a generic declaration

New

Create an instance of a user defined type, or specify a custom constructor

Example

Rem
New creates a BlitzMax variable of the Type specified.
End Rem

SuperStrict

Type MyType
    Field a:Int,b:Int,c:Int
End Type

Local t:MyType
t=New MyType
t.a=20

Print t.a

' if a new method is defined for the type it will also be called

Type MyClass
    Field a:Int,b:Int,c:Int
    Method New()
        Print "Constructor invoked!"
        a=10
    End Method
    
    ' the new method can be overridden to provide even more construction options
    Method New(b:Int, c:Int)
        New() ' the default new can also be called from inside this one
        Self.b = b
        Self.c = c
    End Method
End Type

Local c:MyClass
c=New MyClass
Print c.a

c = New MyClass(5, 15)
Print c.a
Print c.b
Print c.c

Delete

Specify a custom finalizer

Example

Rem
Reserved for future expansions.
End Rem

Self

Reference to this method's type instance

Example

Rem
Self is used in BlitzMax Methods to reference the invoking variable.
End Rem

SuperStrict

Type MyClass
    Global count:Int
    Field id:Int
    
    Method New()
        id=count
        count:+1
        ClassList.AddLast(Self) 'adds this new instance to a global list        
    End Method
End Type

Global ClassList:TList

classlist=New TList

Local c:MyClass

c=New MyClass
c=New MyClass
c=New MyClass

For c=EachIn ClassList
    Print c.id
Next

Super

Reference to the super type instance

Example

Rem
Super evaluates to Self cast to the method's immediate base class.
End Rem

SuperStrict

Type TypeA
    Method Report()
        Print "TypeA reporting"
    End Method
End Type

Type TypeB Extends TypeA
    Method Report()
        Print "TypeB Reporting"
        Super.Report()
    End Method
End Type

Local b:TypeB=New TypeB
b.Report()

Release

Release an integer object handle

Example

Rem
Release removes the internal reference caused by creating an integer handle to a type.
End Rem

Type MyType
    Field bigmap[1024*1024]
End Type

GCCollect
Print GCMemAlloced()

a=New MyType
GCCollect
Print GCMemAlloced()

Release a
GCCollect
Print GCMemAlloced()

Public

Make types, constants, global variables, functions or type members accessible from outside the current source file (default)

Example

Rem
Public makes a variable, function or method accessible from outside the current source file (default).
End Rem

SuperStrict

Public

Global Score:Int,Lives:Int,Health:Int

Private

Global posx:Int,posy:Int,posz:Int

Private

Make types, constants, global variables, functions or type members only accessible from within the current source file.

Example

Rem
Private makes a variable, function or method only accessible from within the 
current source file.
End Rem

SuperStrict

Public

Global Score:Int,Lives:Int,Health:Int

Private

Global posx:Int,posy:Int,posz:Int

Protected

Make type members only accessible from within the current source file and within subtypes.

Example

Rem
Protected
Protected makes a variable, function or method only accessible from within the current source file.
End Rem

Extern

Begin an Extern section (a list of imported external declarations)

Example

Rem
Extern marks the beginning of an external list of function declarations.
End Rem

SuperStrict

Extern 
    Function puts( str$z )
    Function my_puts( str$z )="puts"
End Extern

puts "Using clib's put string!"
my_puts "Also using clib's put string!"

EndExtern

End an Extern section

Example

Rem
EndExtern marks the end of an Extern section.
End Rem

SuperStrict

Extern 
    Function puts( str$z )
End Extern

puts "Using clib's put string!"

Module

Declare module scope and identifier

See the BlitzMax Language Reference for more information on BlitzMax Modules.

Example

Rem
The Module keyword advises the BlitzMax program maker BMK to create a code 
module from the source file.
End Rem

SuperStrict

Module PUB.Sequencer

ModuleInfo "Framework: Audio Sequencer for use with FreeAudio"
ModuleInfo "Copyright: Blitz Research Ltd"
ModuleInfo "Author: Simon Armstrong"
ModuleInfo "Version: 1.00"

ModuleInfo

Define module properties

Example

Rem
ModuleInfo allows properties such as Author and Copyright to be included in a module file.
End Rem

SuperStrict

Module PUB.Sequencer

ModuleInfo "Framework: Audio Sequencer for use with FreeAudio"
ModuleInfo "Copyright: Blitz Research Ltd"
ModuleInfo "Author: Simon Armstrong"
ModuleInfo "Version: 1.00"

Incbin

Embed a data file

Example

Rem
IncBin embeds an external data file in a BlitzMax program that can 
then be read using the "incbin::" device name.
End Rem

' code snippet from demos/firepaint/firepaint.bmx

SuperStrict

Incbin "stars.png"

Local stars:TImage = LoadImage( "incbin::stars.png" )

IncbinPtr

Get start address of embedded data file

Example

Rem
IncBinPtr returns a byte pointer to the specified embedded binary file.
End Rem

SuperStrict

Incbin "incbinptr.bmx"

Local p:Byte Ptr = IncbinPtr("incbinptr.bmx")
Local bytes:Int = IncbinLen("incbinptr.bmx")

Local s:String = String.FromBytes(p,bytes)

Print "StringFromBytes(p,bytes)="+s

IncbinLen

Get length of embedded data file

Example

Rem
IncBinLen returns the size in bytes of the specified embedded binary file.
End Rem

SuperStrict

Incbin "incbinlen.bmx"

Local p:Byte Ptr = IncbinPtr("incbinlen.bmx")
Local bytes:Int = IncbinLen("incbinlen.bmx")

Local s:String=String.FromBytes(p,bytes)

Print "StringFromBytes(p,bytes)="+s

Include

Include effectively 'inserts' the specified file into the file being compiled.

Framework

Framework builds the BlitzMax application with only the module(s) specified rather than the standard set of modules.

Example

' Use the Framework and Import functions to only include the function sets
' that you want to use
'
SuperStrict

Framework Brl.standardio ' so we can use print
Import Brl.random ' so we can use the Rnd Function

Print Rnd(255)

Import

Import declarations from a module or source file

Example

Rem
:Import specifies the external BlitzMax modules and source files used by the program.
End Rem

SuperStrict

Framework BRL.GlMax2D

Import BRL.System

Graphics 640,480,32

While Not KeyHit(KEY_ESCAPE)
    Cls
    DrawText "Minimal 2D App!",0,0
    Flip
Wend

Assert

Throw a RuntimeError if a condition is false

Example

Rem
Assert generates a BlitzMax runtime error if the specified condition is false.
End Rem

SuperStrict

Local a:TImage = LoadImage("nonexistant image file")
Assert a,"Image Failed to Load"

Goto

Transfer program flow to specified label

Example

Rem
Causes program execution to jump to the #label specified.
End Rem

Print "one"
Goto here
Print "two"
#here
Print "three"

Try

Begin declaration of a Try block

Example

Rem
Begin declaration of a Try block.
End Rem

SuperStrict

Local a:Int

Try
    Repeat
        a:+1
        Print a
        If a>20 Throw "chunks"
    Forever
Catch e:String
    Print "caught exception "+e
EndTry

Catch

Catch an exception object in a Try block

Example

Rem
Catch defines an exception handler following a Try..EndTry Block.
End Rem

SuperStrict

Local a:Int
Try
    Repeat
        a:+1
        Print a
        If a>20 Throw "chunks"
    Forever
Catch e:String
    Print "caught exception "+e
EndTry

Finally

Execute a block of code upon exiting a Try or Catch block

EndTry

End declaration of a Try block

Example

Rem
EndTry
EndTry marks the end of a Try block.
End Rem

Throw

Throw an exception object to the enclosing Try block

Example

Rem
Throw generates a BlitzMax exception.
End Rem

SuperStrict

Local a:Int
Try
    Repeat
        a:+1
        Print a
        If a>20 Throw "chunks"
    Forever
Catch e:String
    Print "caught exception "+e
EndTry

DefData

Define classic BASIC style data

Example

' defdata.bmx

SuperStrict

Local name:String
Local age:Int, skill:Int

ReadData name
ReadData age,skill

Print "name="+name+" age="+age+" skill="+skill

DefData "Simon",37,5000

ReadData

Read classic BASIC style data

RestoreData

Restore classic BASIC style data

Example

' restoredata.bmx

SuperStrict

Local name:String, age:Int, skill:Int

For Local i:Int = 1 To 5
    RestoreData mydata  'reset the data pointer everly loop so we don't read past the end
    ReadData name,age,skill
    Print "name="+name+" age="+age+" skill="+skill
Next

#mydata 'program label that can be used with the RestoreData command

DefData "Simon",37,5000

And

Conditional 'And' binary operator

Example

Rem
And is a boolean operator that performs the AND function.
End Rem

SuperStrict

For Local i:Int = 1 To 10
    If i>3 And i<6 Print "!" Else Print i
Next

Or

Conditional 'Or' binary operator

Example

Rem
Or is a boolean operator that performs the OR function.
End Rem

SuperStrict

For Local i:Int = 1 To 5
    If i=2 Or i=4 Print "!" Else Print i
Next

Not

Conditional 'Not' binary operator

Example

Rem
Not is a boolean unary operator that performs the NOT function.
End Rem

SuperStrict

Print Not 0         'prints 1 (TRUE)
Print Not 20        'prints 0 (FALSE)

Shl

Bitwise 'Shift left' binary operator

Example

Rem
Shl is a binary operator that performs the shift to left function.
End Rem

SuperStrict

Local b:Int = 1
For Local i:Int = 1 To 32
    Print Bin(b)
    b=b Shl 1
Next

Shr

Bitwise 'Shift right' binary operator

Example

Rem
Shr is a binary operator that performs the shift to right function.
End Rem

SuperStrict

Local b:Int = -1
For Local i:Int = 1 To 32
    Print Bin(b)
    b=b Shr 1
Next

Sar

Bitwise 'Shift arithmetic right' binary operator

Example

Rem
Sar is a binary operator that performs the arithmetic shift to right function.
End Rem

SuperStrict

Local b:Int = $f0f0f0f0
For Local i:Int = 1 To 32
    Print Bin(b)
    b=b Sar 1
Next

Len

Number of characters in a string or elements in an array

Example

Rem
Len is a BlitzMax operator that returns the number of elements in a container Type.
End Rem

SuperStrict

Local a:String = "BlitzMax Rocks"
Print Len a 'prints 14

Local b:Int[]
Print Len b     'prints 0

b=New Int[20]
Print Len b     'prints 20

Mod

Numeric 'modulus' or 'remainder' binary operator

Example

Rem
Mod is a mathematical operator that performs the Modulo function.
End Rem

SuperStrict

For Local i:Int = 6 To -6 Step -1
    Print i+" Mod 3="+(i Mod 3)
Next

Varptr

Find the address of a variable

Example

Rem
Varptr returns the address of a variable in system memory.
End Rem

SuperStrict

Local a:Int
Local p:Int Ptr

a=20
p=Varptr a
Print p[0]

SizeOf

Size, in bytes, occupied by a variable, string, array or object

Example

Rem
SizeOf returns the number of bytes of system memory used to store the variable.
End Rem

SuperStrict

Type MyType
    Field a:Int,b:Int,c:Int
End Type

Local t:MyType
Print SizeOf t  'prints 12

Local f!
Print SizeOf f  'prints 8

Local i:Int
Print SizeOf i  'prints 4

Local b:Byte
Print SizeOf b  'prints 1

Local a:String="Hello World"
Print SizeOf a  'prints 22 (unicode characters take 2 bytes each)

Asc

Get character value of the first character of a string

Example

Rem
Asc returns the unicode value of the first character of a string.
End Rem

SuperStrict

Print Asc("A")  '65
Print "A"[0]    '65 - equivalent index style implementation

Chr

Create a string of length 1 with a character code

Example

Rem
Chr returns a String of length 1 containing the unicode character of the value.
End Rem

SuperStrict

Print Chr(65)   'A

StackAlloc

Allocates memory from the stack.

This memory is automatically freed on leaving the function where it was created. It should not be freed, or returned from the function.

FieldOffset

Returns the offset in bytes for a field of the specified Type or Struct.

StaticArray

Denotes an array as a static array, with its content allocated on the stack.