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SPECIFICATION
#Angle specification
Many details of the specification are to be found in separate articles like data, list ...
cat{
length:7cm
hair-color:{r=1 g=0 b=0}
form{
dimensions=(3, length*2)
}
kill{print '🕱'}
}
The data format is a superset to (a subset) of emascript,json,css,wasp,…
While it looks very different to lisp, it is in fact a very similar
Data calculous "lisp with builtin assignment and hashes"
With very few axioms and primitives:
-
:pair : turn two node_pointer into a pair,a:3(hashed+symbolic). almost identical to: -
=value : turn two node_pointer into a variable pair,a=3 -
,list : turn two node_pointer into a list. Append if one is a list. 'cons' in lisp -
;list : end expression/statements, list inside a block. if 1 : 0 ; -
.#ofin'sselection: garden of house == house.garden == house's garden xs.1 xs#1 -
|pipe/then : output of last command as input for next command.ls ~ | sort -
-
addplustimespower^… and logicalandorxornot
Question: substraction|concatenation|range hair-color vs a-b vs 2001-2020
for static content , ; are identical
{1 2 3} == {1,2,3} == {1;2;3}
for static content [],(),{} are identical
[1,2,3]==(1,2,3)=={1,2,3}
[a:3]==(a:3)=={a:3}
If attatched to objects, [],(),{} have different semantics:
[export]square(a:int){a*a}
- […] attributes meta modifiers decorators annotations adjectives adverbs
- (…) groups parameters signatures attributes lists head
- {…} body blocks maps lambdas closures children node_pointer
- «…» other brackets behave like ()/{} until specified
- x[…] index patterns selectors matches
brackets: content of () is evaluated, {} is deferred (block/lambda)
[a]b == b[a] == a b if a is modifier/operator a + b == + a b if feasible
f a b = f(a b) if f is a method/operator/functor
All kinds of brackets are often optional thanks to operator prescedence
a:=1 2 3 == a=(1,2,3)
[extern]void() == extern void
Each line is treated as a group by default, unless escaped with
so in lisp (add (1 2)) is just add 1 2 in angle
Brackets have different semantics depending on their context, this is NOT reflected in the data structure, only in its evaluation:
[…]object vs object[…]
[attributes] are commonly written on the left side of objects [indices] on the right site.
e.g. [mutable]list xs but xs[1]=7
Question: what about xs[mutable]=7?
the preferred way to index properties in objects to use the 'of' / 'in' notation
show color of cat or dot notation
show cat.color
list items are indexed from 0 in ordinary [] notation items[0]
list items are accessed from 1 in selector # notation item#1
x=color cat{color:red} cat.color // red cat.x // ø cat#x // red cat[x] // red cat#color // red unless color is a variable cat[color] // red unless color is a variable
Question: how is value indexing done in english? property=color; get this property from cat
car(list)=list#1 cdr(list)=rest of list=list…
To make sure an object is evaluated, invoke it with ! or ()
a=7
x={a+1}
print x // {a+1}
print x! // 8
a=8
print x! // 9
parameters are evaluated if given in () and deferred if given as {} print x // 9 print(x) // 9 print{x} // {a+1} print[x] // print has no property {a+1}
objects are evaluated if given in () and deferred if given as {} y=(a+1) // 8
NOTE: Everything inside {blocks} is deferred, including (groups)
a=7;x={print(a+1)};a=1;x() // 2
For instant template evaluation inside {blocks} use $ :
a=7;x={print($a+1)};a=1;x() // 8
NOTE: Everything inside (groups) is evaluated, including {blocks} z={x} print(z) // ({a+1}) (8+1) (9) 9
block is a builtin data type similar to 'object' (inspired by ruby)
Every group […] (…) {…} «…» is a block at first until special semantics are given.
A block is basically a deferred multiline lambda
f a b = f(a b) if f is a functor example functor: if.signature == condition:block then:block [optional]otherwise:block if(a=b){go!}{stop!}
if could be implemented within the language:
if(block condition, block body, block otherwise){
}
Having blocks as first class citizens makes a lot of code cleaner: square(x){x^2} {it^2}[1 2 3] == [ 1 4 9]
blocks can be applied to objects from left or from right {a*a}(a=7) == 49
blocks can be applied/evaluated via !
a=6;{a*a}! #36
blocks can be applied/evaluated via ()
ATTENTION
(){} has different semantics to {}()
the first is a deferred list [group(),block()]
the second is an applied list [block(),group()] where the group is provided as context for the block
example: (x){xx} a lambda (anonymous function) {xx}(x=5) #25 evaluated on the spot
This is particularily important because normaly () is just the empty object ø, but {go}() will EXECUTE the block containing the statement 'go'; if 'go' was declared as function before, it will return the result of 'go'
b=7 x={a=b} x.a # b (here:7) y=x! y=={a=7} b=5 x.a # b (here:5) y=={a=7} # unchanged because b was resolved
blocks can be applied to lists from left or from right {it^2}[1 2 3]
While some blocks might look identical to javascript, the underlying logic is much more unified. Read the rest of this document for details.
a={b:1,c:d()}
Has near identical behavior in javascript and angle:
a variable('node'/'object') with name 'a' is created and has the properties b and c. while b is static, c recieves the dynamic value of d() at construction.
json sucks, angle is more like ecmascript:
a={b:1,c:d()} legal angle and javascript
legal syntax only in angle:
a:{b=1,c{d()}}
hello:world root maps
{1:i i^2:-1} no restriction on map keys
{a:b} values are symbolic until evaluated (see above)!
Attention:
objects can be constructed with a{} a={} a:{} mostly equivalently in javascript '=' is used for variable setters and ':' is used for fields
Groups, blocks, lists () Node *param == group attributes meta modifiers decorators annotations {} Node *children == block body content 'set':setters!=Set? Setter Problem [] Node *list == selector pattern match a[b]=c == a.b=c ab=c (a that b)=c a@b a~b=c (a.filter(b))=c
DANGER a,b=c,d TWO READINGS
- (a;b=c;d) 2. (a,b)=(c,d) a b:c d == a,(b:c),d "short-binding" a b=c d == (a,b)=(c,d) "number- binding"
usually '=' is number-binding, meaning it has higher prescedence than other operations, so the second reading is default. Within Groups, '=' is shortbinding like ':' a(href='link' hidden) BUT DANGER: group is default bag CONTRADICTION
Solution? '=' be left-short-binding a b=c d == (a b):c,d NO WAY Solution: just write a(href:link style="") Solution: short-binding in lists, but how do we know?
Diffenence of maps and constructors
color:{r=1 g=0 b=0} creates object called 'color' with r,g,b fields
color{r=1 g=0 b=0} constructs instance of color class with r,g,b parameters
These are EQUIVALENT unless there is a constructor, e.g.
color{construct(r,g,b){this.rgb=r+g*2^8+b*2^16}}
This is an example of class name as variable name. In this context color is both a variable with name 'color' and of type Color.
cats=[cat{color=brown},cat{color=yellow}] ok, two cats
cats={cat{color=brown};cat{color=yellow}} danger, cat property gets reassigned! really?
cats(){color=green;sleep 1;color=blue} ok, two setters in sequence
Then these two objects should still behave very similarily. Especially the constructor arguments should be unmodified and are automatically accessible: color.r==1 no matter what.
Assignment and object creation foo{bar:3} #object creation foo(bar:3) #object creation if (implicit) constructor, else function call foo:{bar:3} #property assignment (nested objects) foo={bar:3} #variable assignment (of calling context)
foo:=(x y){x+y} # function creation :foo(x y){x+y} # function creation to foo(x y){x+y} # function creation