Top-level elements
- #include
- #pragma
- class
- interface
- pooldic
Comments
#! comment text
// comment text
/* comment text */
Literal notations
-
200 decimal integer
-
2r1100 binary integer
-
16rFF00 hexadecimal integer
-
20p9999.99 fixed-point decimal where 20 is the number of digits after the point
-
999.9 fixed-point decimal
-
$X character
-
C'X' -> charcter??
-
C"X" -> character??
-
'XXXX' string literal
-
"XXXX" string litearl with escaping
-
B'XXXXXX' -> byte array literal
-
B"XXXXX" -> byte array literal with escaping
-
#XXXX symbol
-
#'XXXX' quoted symbol
-
#"XXXX" quoted symbol with escaping
-
#\e123 Error literal
-
#\pB8000000 SmallPointer(smptr) literal
-
#() Array. Comma as element delimiter is optional
-
#[] ByteArray. Comma as element delimiter is optional #[ 16r10, 16r20, 16r30 ] #[ "\x10\x20", "\x30" ]
-
#{} Dictionary - not supported yet
The followings are not literals. The followings forms expressions.
- ##() Array expression. Comma required to delimit elements
- ##[] ByteArray expression. Comma required to delimit elements
- ##{} Dictionary expression. Comma required to delimit elements
The followings are not implemented. but can i do something like these?
- S#[] String literal with each character specified. S%{A B C '\n'}
- S#{} String with dynamic expression
- S#{ 65 asCharacter, 64 asCharacter }
Class
class MyClass(Object)
{
method show: this
{
}
}
Class attributes
The word class can be followed by attribute list enclosed in parenthesis. e.g.) class(#limited,#immutable)
- #limited - not instantiable with new.
- #immutable - instantiated object to be read-only.
- #final - disallow subclasses.
- #uncopyable - instantiated object not to be copied.
- #byte, #character, #halfword, #word, #liword, #pointer - specify the type of a non-pointer object. a non-pointer type can have an additional size enclosed in parenthesis. e.g.) #character(2) a non-pointer object is not allowed to have named instanced variables. a non-pointer object is always variable indexed.
- #pointer - specify a pointer variable indexed object. an instantiate object can have extra object pointers in additon to named instance variables.
class(#word(2)) X(Object) { }
X new -> create an object with 2 words.
X new: 4 -> create an object with 6 words.
if an object is asked to instantiate with trailer in the class defintion, it becomes uncopyable, without the #uncopyable attribute.
class Shader(Object) from 'shader'
{
// if the shaer module calls moo_setclasstrsize(), an instance of Shader is uncopyable
}
Pool dictionary
pooldic MyData
{
A := 20,
B := 30,
C := 40
}
class MyClass(Object)
{
import MyData.
method x ()
{
MyData.A dump.
C dump. // if imported, it doesn't require prefixing with MyData.
}
}
class MyClass2(Object)
{
pooldic Const
{
A := 20,
B := 30
}
method x()
{
A dump. // the nested pooldic is auto-imported.
Const.A dump.
self.Const dump.
}
}
class MyClass3(MyClass2)
{
pooldic Const
{
A := MyClass2.Const.A // pooldic is not inherited. need redefinition for auto-import
B := MyClass2.Const.B
}
}
class MyClass4(MyClass2)
{
import MyClass2.Const. // similar to redefinition inside the class. it won't be available MyClass4.Const as such is not available.
method x
{
MyClass2.Const at: #XXX put: 'QQQQQQQQQQQQQQ'. // you can add a new item dynamically,
(MyClass2.Const at: #XXX) dump. // and can access it.
// the compiler doesn't recognize the dynamically added item as MyClass2.Const.XXX
}
}
Flow Control
k := if (i < 20) { 30 } else { 40 }.
if (a < 10) { ... }
elif (a < 20) { ... }
else { ... }.
ifnot (i < 20) { 30 } else { 40 }. /* TODO: ifnot or nif? elifnot or elnif? */
if (a < 10) { .. }
elifnot (a > 20) { ... }
else { ... }.
while (true)
{
}.
until (a > b)
{
}.
do
{
} while (a > b).
do
{
} until (a > b).
[a > b] whileTrue: [ ... ].
[a > b] whileFalse: [ ... ].
1 to: 20 do: [:count | ... ].
1 to: 10 by: 3 do: [:count | ... ].
30 timesRepeat: [ ... ].
Exception handling
Exception signal. Exception signal: "message".
[ ... ] on: Exception do: [:ex | ... ].
ex retry. ex resume. ex resume: value. ex return: value.
return from context(method/block)
explicit return operators
^ return_stacktop
^^ local_return
implicit return when the end of the context is reached
- a method context returns the receiver.
- a block context returns the last evaluated value. if nothing has been evaluated, nil is returned.
goto
goto jump_label.
jump_label:
a + b.
goto inside a block context.
[ 1 + 2. goto r. 3 + 4. r: 99 ]
goto must not cross the boundary of the block context.
this is invalid. cannot jump into a block from outside
and vice versa.
goto x.
[ x:
1 + 2 ].
Type checking
Type checking not implemented yet.
class SampleClass(Object)
{
method run => Integer
{
}
method execute((Integer)a,(Integer)b) => Integer
{
}
method handle: (Object)this with: (a Integer)care => Integer
{
}
}
TODO: How to specify return type of a block? or How to specify parameter type to a block? How to evaluate a block type-safely?
[ :(Integer)a :(Integer)b => Integer |
| (Integer)c (Integer)d }
a + b
] with: 20 with: 10
the method value is a variadic method. and it is a primitive.
[ :a :b | a + b ](1, 20) <---- syntax sugar for [:a :b | a + b] value(1, 20).
[:(Integer)a :(Integer)b => Integer | a + b ] value("kkkk", 20)
-> the first argument violates the expected type.
-> argument types to a method is defined in the method signature.
-> but the block argument types are specified in the block itself.
-> so it doesn't seem natural to achieve type safety without treating 'value' specially.
-> create a shorthand expression for 'value' [:(Integer)a :(Integer)b => (Integer) | a + b ](1, 2)
-> ] followed by ( ===> shorthand expression for value.
-> it looks more sensible to treat this () specially
what looks better as a shorthand expression for block value?
[ :a :b | a + b ](10, 20)
[ 10 + 20 ]() // no arguments
[ :a :b | a + b ]->(10, 20). // -> cannot form a valid binary selector. must exclude it from binary selector patterns
[ 10 + 20 ]->() // if no arugments are required.
continuation?
| a |
a->()? block value?
| (Block)a |
a->()? block value?
FFI
ffi := FFI new: 'libc.so.6'.
[
(ffi call: #printf signature: 's|sl>i' arguments: #("[%s ffi test %ld]\n" "sloppy" 12345678)) dump.
(ffi call: #printf signature: 's>i' arguments: #("[%% ffi test %%]\n")) dump.
(ffi call: #puts signature: 's>i' arguments: #("this is ffi test")) dump.
(ffi call: #time signature: 'p>l' arguments: #(#\p0)) dump.
]
ensure: [
ffi close.
].
Command line options
moo --log /dev/stderr ../kernel/test-001.moo
moo --log /dev/stderr,warn+ ../kernel/test-001.moo