Category talk:Wren-trait: Difference between revisions
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→Source code: Now uses Wren S/H lexer.
(Added source code for new 'Wren-trait' module.) |
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===Source code===
<
/* Cloneable is an abstract class which enables child classes to automatically be
recognized as 'cloneable' by overriding the 'clone' method.
*/
class Cloneable {
clone() { this } /* to be overridden by child class */
}
/* CloneableSeq is an abstract class which enables child classes to automatically be
recognized as both Sequences and 'cloneable' by overriding the 'clone' method.
*/
class CloneableSeq is Sequence {
clone() { this } /* to be overridden by child class */
}
/*
Comparable is an abstract class which enables child classes to automatically
inherit the comparison operators by just overriding the 'compare' method.
Comparable itself inherits from Cloneable though if one does not wish to override
the 'clone' method, it will just return the current object by default.
*/
class Comparable is Cloneable {
compare(other) {
// This should be overridden in child classes to return -1, 0 or +1
Line 13 ⟶ 29:
< (other) { compare(other) < 0 }
> (other) { compare(other) > 0 }
<=(other) { compare(other) <= 0 }
>=(other) { compare(other) >= 0 }
Line 20 ⟶ 36:
}
/* ByRef wraps a value to enable it to be passed by reference to a method or function. */
class ByRef {
// Constructs a new ByRef object.
construct new(value) {
_value = value
}
// Properties to get and set the value of the current instance.
value { _value }
value=(v) { _value = v }
// Returns the string representation of the current instance's value.
toString { _value.toString }
}
/*
ByKey wraps a reference type object to enable it to be used as a Map key. It does this
by using a counter to create a unique integral key for each such object and maintaining
an internal map which enables the object to be quickly retrieved from its key.
*/
class
// Retrieves a ByKey object from its key. Returns null if the key is not present.
static [key] { __map ? __map[key] : null }
// Retrieves a ByKey object's key from the object it wraps.
// If the same object has been wrapped more than once, returns the first key found which may
// not be the lowest. Returns 0 if the object is unwrapped.
for (me in __map) {
}
return 0
}
// Returns the number of objects currently in the internal map.
static mapCount { __tally ? __map.count : 0 }
// Returns the total number of keys created to date.
static keyCount { __tally ? __tally : 0 }
// Constructs a new ByKey object.
construct new(obj) {
_obj = obj
if (!__tally) {
__map = {}
__tally = 1
} else {
}
_key = __tally
__map[_key] = this
}
// Properties
obj { _obj } // returns the current instance
key { _key } // returns the current instance's key
// Removes the current instance from the internal map and sets it to null.
unkey() {
__map.remove(_key)
_obj = null
}
// Returns the string representation of the current instance.
toString { _obj.toString }
}
/*
Const represents a group of individually named read-only values which are
stored internally in a map. Any attempt to change such a value is ignored
though they can be removed from the map.
*/
class
// Returns the value of 'name' if it is present in the internal map
// or null otherwise.
static [name] { (__cmap && __cmap.containsKey(name)) ? __cmap[name] : null }
// Associates 'value' with 'name' in the internal map.
// If 'name' is already in the map, the change is ignored.
static [name]=(value) {
if (!__cmap) __cmap = {}
if (!__cmap.containsKey(name)) {
__cmap[name] = value
}
}
// Removes 'name' and its associated value from the internal map and returns
// that value. If 'name' was not present in the map, returns null.
static remove(name) { __cmap.remove(name) }
// Returns a list of the entries (name/value pairs) in the internal map.
static entries { __cmap.toList }
}
/*
Var represents a group of individually named read/write values which are
stored internally in a map. It can be used to simulate the creation of
variables at runtime. It can also be used to allow variable names which would
otherwise be illegal in Wren such as those which include non-ASCII characters.
*/
class Var {
// Returns the value of 'name' if it is present in the internal map
// or null otherwise.
static [name] { (__vmap && __vmap.containsKey(name)) ? __vmap[name] : null }
// Associates 'value' with 'name' in the internal map.
// Any existing value is replaced.
static [name]=(value) {
if (!__vmap) __vmap = {}
__vmap[name] = value
}
// Removes 'name' and its associated value from the internal map and returns
// that value. If 'name' was not present in the map, returns null.
static remove(name) { __vmap.remove(name) }
// Returns a list of the entries (name/value pairs) in the internal map.
static entries { __vmap.toList }
}
/* TypedVar is similar to Var except that simulated variables always retain the
same type as they had when they were originally created.
*/
class TypedVar {
// Returns the value of 'name' if it is present in the internal map
// or null otherwise.
static [name] { (__vmap && __vmap.containsKey(name)) ? __vmap[name] : null }
// Associates 'value' with 'name' in the internal map.
// Any existing value is replaced. However, it is an error to attempt to replace
// an existing value with a value of a different type.
static [name]=(value) {
if (!__vmap) __vmap = {}
if (!__vmap.containsKey(name)) {
__vmap[name] = value
} else {
var vtype = value.type
var mtype = __vmap[name].type
if (vtype != mtype) {
Fiber.abort("Expecting an item of type %(mtype), got %(vtype).")
} else {
__vmap[name] = value
}
}
}
// Removes 'name' and its associated value from the internal map and returns
// that value. If 'name' was not present in the map, returns null.
static remove(name) { __vmap.remove(name) }
// Returns a list of the entries (name/value pairs) in the internal map.
static entries { __vmap.toList }
}</syntaxhighlight>
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