# You are allowed to redistribute it and sell it, alone or is a part of
# another product.
+# Most minimal classes and methods.
# This module is the root of the standard module hierarchy.
-package kernel
+module kernel
import end # Mark this module is a top level one. (must be only one)
+`{
+#include <errno.h>
+`}
+
###############################################################################
# System Classes #
###############################################################################
#
# Currently, Object is also used to collect all top-level methods.
interface Object
+ # Type of this instance, automatically specialized in every class
+ #
+ # A common use case of the virtual type `SELF` is to type an attribute and
+ # store another instance of the same type as `self`. It can also be used as as
+ # return type to a method producing a copy of `self` or returning an instance
+ # expected to be the exact same type as self.
+ #
+ # This virtual type must be used with caution as it can hinder specialization.
+ # In fact, it imposes strict restrictions on all sub-classes and their usage.
+ # For example, using `SELF` as a return type of a method `foo`
+ # forces all subclasses to ensure that `foo` returns the correct and updated
+ # type.
+ # A dangerous usage take the form of a method typed by `SELF` which creates
+ # and returns a new instance.
+ # If not correctly specialized, this method would break when invoked on a
+ # sub-class.
+ #
+ # A general rule for safe usage of `SELF` is to ensure that inputs typed
+ # `SELF` are stored in attributes typed `SELF` and returned by methods typed
+ # `SELF`, pretty much the same things as you would do with parameter types.
+ type SELF: Object
+
# The unique object identifier in the class.
# Unless specific code, you should not use this method.
# The identifier is used internally to provide a hash value.
fun object_id: Int is intern
- # Return true is `self' and `other' have the same dynamic type.
+ # Return true if `self` and `other` have the same dynamic type.
# Unless specific code, you should not use this method.
fun is_same_type(other: Object): Bool is intern
- # Have `self' and `other' the same value?
- ##
+ # Return true if `self` and `other` are the same instance.
+ # Unless specific code, you should use `==` instead.
+ fun is_same_instance(other: nullable Object): Bool is intern
+
+ # Have `self` and `other` the same value?
+ #
# The exact meaning of "same value" is let to the subclasses.
- # Implicitly, the default implementation, is ==
- fun ==(other: nullable Object): Bool do return self is other
+ # Implicitly, the default implementation, is `is_same_instance`
+ fun ==(other: nullable Object): Bool do return self.is_same_instance(other)
- # Have `self' and `other' different values?
- ##
- # != is equivalent with "not =".
+ # Have `self` and `other` different values?
+ #
+ # != is equivalent with "not ==".
fun !=(other: nullable Object): Bool do return not (self == other)
# Display self on stdout (debug only).
- # This method MUST not be used by programs, it is here for debugging only and can be removed without any notice
+ # This method MUST not be used by programs, it is here for debugging
+ # only and can be removed without any notice
fun output
do
'<'.output
end
# Display class name on stdout (debug only).
- # This method MUST not be used by programs, it is here for debugging only and can be removed without any notice
+ # This method MUST not be used by programs, it is here for debugging
+ # only and can be removed without any notice
fun output_class_name is intern
- # Quit the program with a specific return code
- protected fun exit(exit_value: Int) is intern
-
- # Return the global sys object, the only instance of the `Sys' class.
- protected fun sys: Sys is intern
+ # The hash code of the object.
+ # Assuming that a == b -> a.hash == b.hash
+ #
+ # Without redefinition, it is based on the `object_id` of the instance.
+ fun hash: Int do return object_id / 8
end
# The main class of the program.
-# `Sys' is a singleton class, its only instance is `sys' defined in `Object'.
-# `sys' is used to invoke methods on the program on the system.
+# `Sys` is a singleton class, its only instance is `sys` defined in `Object`.
+# `sys` is used to invoke methods on the program on the system.
class Sys
# Instructions outside classes implicitly redefine this method.
fun main do end
+
+ # The entry point for the execution of the whole program.
+ # Its job is to call `main` but some modules may want to refine it
+ # and inject specific work before or after the main part.
+ fun run do main
+
+ # Number of the last error
+ fun errno: Int is extern `{
+ return errno;
+ `}
end
+# Quit the program with a specific return code
+fun exit(exit_value: Int) is intern
+
+# Return the global sys object, the only instance of the `Sys` class.
+fun sys: Sys is intern
+
+
###############################################################################
# Abstract Classes #
###############################################################################
# The ancestor of class where objects are in a total order.
# In order to work, the method '<' has to be redefined.
interface Comparable
- # What `self' can be compared to?
+ # What `self` can be compared to?
type OTHER: Comparable
- # Is `self' lesser than `other'?
+ # Is `self` lesser than `other`?
fun <(other: OTHER): Bool is abstract
- # not `other' < `self'
- # Note, the implementation must ensure that: (x<=y) == (x<y or x==y)
+ # not `other` < `self`
+ # Note, the implementation must ensure that: `(x<=y) == (x<y or x==y)`
fun <=(other: OTHER): Bool do return not other < self
- # not `self' < `other'
- # Note, the implementation must ensure that: (x>=y) == (x>y or x==y)
+ # not `self` < `other`
+ # Note, the implementation must ensure that: `(x>=y) == (x>y or x==y)`
fun >=(other: OTHER): Bool do return not self < other
- # `other' < `self'
+ # `other` < `self`
fun >(other: OTHER): Bool do return other < self
# -1 if <, +1 if > and 0 otherwise
return c <= self and self <= d
end
- # The maximum between `self' and `other' (prefers `self' if equals).
+ # The maximum between `self` and `other` (prefers `self` if equals).
fun max(other: OTHER): OTHER
do
if self < other then
end
end
- # The minimum between `self' and `c' (prefer `self' if equals)
+ # The minimum between `self` and `c` (prefer `self` if equals)
fun min(c: OTHER): OTHER
do
if c < self then
redef type OTHER: Discrete
# The next element.
- fun succ: OTHER do return self + 1
+ fun successor(i: Int): OTHER is abstract
# The previous element.
- fun prec: OTHER do return self - 1
-
- # The `i' th successor element.
- fun +(i: Int): OTHER is abstract
-
- # The `i' th previous element.
- fun -(i: Int): OTHER is abstract
+ fun predecessor(i: Int): OTHER is abstract
# The distance between self and d.
- # 10.distance(15) # --> 5
- # 'Z'.distance('A') # --> 25
+ #
+ # assert 10.distance(15) == 5
+ # assert 'Z'.distance('A') == 25
fun distance(d: OTHER): Int
do
var cursor: OTHER
var nb = 0
while cursor < stop do
- cursor = cursor.succ
+ cursor = cursor.successor(1)
nb += 1
end
return nb
end
end
+# A numeric value supporting mathematical operations
+interface Numeric
+ super Comparable
+
+ redef type OTHER: Numeric
+
+ # Addition of `self` with `i`
+ fun +(i: OTHER): OTHER is abstract
+
+ # Substraction of `i` from `self`
+ fun -(i: OTHER): OTHER is abstract
+
+ # Inverse of `self`
+ fun -: OTHER is abstract
+
+ # Multiplication of `self` with `i`
+ fun *(i: OTHER): OTHER is abstract
+
+ # Division of `self` with `i`
+ fun /(i: OTHER): OTHER is abstract
+
+ # The integer part of `self`.
+ #
+ # assert (0.0).to_i == 0
+ # assert (0.9).to_i == 0
+ # assert (-0.9).to_i == 0
+ # assert (9.9).to_i == 9
+ # assert (-9.9).to_i == -9
+ fun to_i: Int is abstract
+
+ # The float equivalent of `self`
+ #
+ # assert 5.to_f == 5.0
+ # assert 5.to_f != 5 # Float and Int are not equals
+ fun to_f: Float is abstract
+
+ # Is this the value of zero in its domain?
+ fun is_zero: Bool do return self == zero
+
+ # The value of zero in the domain of `self`
+ fun zero: OTHER is abstract
+
+ # The value of `val` in the domain of `self`
+ #
+ # assert 1.0.value_of(2) == 2.0
+ # assert 1.0.value_of(2.0) == 2.0
+ # assert 1.value_of(2) == 2
+ # assert 1.value_of(2.0) == 2
+ fun value_of(val: Numeric): OTHER is abstract
+end
+
###############################################################################
# Native classes #
###############################################################################
# Native Booleans.
-# `true' and `false' are the only instances.
+# `true` and `false` are the only instances.
+#
# Boolean are manipulated trough three special operators:
-# `and', `or', `not'.
+# `and`, `or`, `not`.
+#
# Booleans are mainly used by conditional statement and loops.
universal Bool
redef fun object_id is intern
redef fun ==(b) is intern
redef fun !=(b) is intern
redef fun output is intern
+ redef fun hash do return to_i
+
+ # 1 if true and 0 if false
+ fun to_i: Int
+ do
+ if self then
+ return 1
+ else
+ return 0
+ end
+ end
end
# Native floating point numbers.
# Corresponds to C float.
universal Float
+ super Numeric
+
+ redef type OTHER: Float
+
redef fun object_id is intern
+ redef fun ==(i) is intern
+ redef fun !=(i) is intern
redef fun output is intern
- fun <=(i: Float): Bool is intern
- fun <(i: Float): Bool is intern
- fun >=(i: Float): Bool is intern
- fun >(i: Float): Bool is intern
- fun +(i: Float): Float is intern
- fun -: Float is intern
- fun -(i: Float): Float is intern
- fun *(i: Float): Float is intern
- fun /(i: Float): Float is intern
-
- # The integer part of `self'.
- fun to_i: Int is intern
+ redef fun <=(i): Bool is intern
+ redef fun <(i): Bool is intern
+ redef fun >=(i): Bool is intern
+ redef fun >(i): Bool is intern
+
+ redef fun +(i) is intern
+ redef fun - is intern
+ redef fun -(i) is intern
+ redef fun *(i) is intern
+ redef fun /(i) is intern
+
+ redef fun to_i is intern
+ redef fun to_f do return self
+
+ redef fun zero do return 0.0
+ redef fun value_of(val) do return val.to_f
+
+ redef fun <=>(other)
+ do
+ if self < other then
+ return -1
+ else if other < self then
+ return 1
+ else
+ return 0
+ end
+ end
+
+ redef fun is_between(c, d)
+ do
+ if self < c or d < self then
+ return false
+ else
+ return true
+ end
+ end
+
+ # Compare float numbers with a given precision.
+ #
+ # Because of the loss of precision in floating numbers,
+ # the `==` method is often not the best way to compare them.
+ #
+ # ~~~
+ # assert 0.01.is_approx(0.02, 0.1) == true
+ # assert 0.01.is_approx(0.02, 0.001) == false
+ # ~~~
+ fun is_approx(other, precision: Float): Bool
+ do
+ assert precision >= 0.0
+ return self <= other + precision and self >= other - precision
+ end
+
+ redef fun max(other)
+ do
+ if self < other then
+ return other
+ else
+ return self
+ end
+ end
+
+ redef fun min(c)
+ do
+ if c < self then
+ return c
+ else
+ return self
+ end
+ end
end
# Native integer numbers.
# Correspond to C int.
universal Int
super Discrete
+ super Numeric
+
redef type OTHER: Int
+ redef fun successor(i) do return self + i
+ redef fun predecessor(i) do return self - i
+
redef fun object_id is intern
+ redef fun hash do return self
redef fun ==(i) is intern
redef fun !=(i) is intern
redef fun output is intern
redef fun >=(i) is intern
redef fun >(i) is intern
redef fun +(i) is intern
- fun -: Int is intern
+
+ redef fun - is intern
redef fun -(i) is intern
- fun *(i: Int): Int is intern
- fun /(i: Int): Int is intern
- fun %(i: Int): Int is intern
+ redef fun *(i) is intern
+ redef fun /(i) is intern
+
+ # Modulo of `self` with `i`.
+ #
+ # Finds the remainder of division of `self` by `i`.
+ #
+ # assert 5 % 2 == 1
+ # assert 10 % 2 == 0
+ fun %(i: Int): Int is intern
+
+ redef fun zero do return 0
+ redef fun value_of(val) do return val.to_i
+
+ # `i` bits shift fo the left (aka <<)
+ #
+ # assert 5.lshift(1) == 10
fun lshift(i: Int): Int is intern
- fun rshift(i: Int): Int is intern
- # The float equivalent of `self'
- fun to_f: Float is intern
+ # `i` bits shift fo the right (aka >>)
+ #
+ # assert 5.rshift(1) == 2
+ fun rshift(i: Int): Int is intern
+
+ redef fun to_i do return self
+ redef fun to_f is intern
- redef fun succ is intern
- redef fun prec is intern
redef fun distance(i)
do
var d = self - i
return -d
end
end
-
+
redef fun <=>(other)
do
if self < other then
end
end
- # The character whose ASCII value is `self'.
+ # The character whose ASCII value is `self`.
+ #
+ # assert 65.ascii == 'A'
+ # assert 10.ascii == '\n'
fun ascii: Char is intern
- # Number of digits of an integer in base `b' (plus one if negative)
+ # Number of digits of an integer in base `b` (plus one if negative)
+ #
+ # assert 123.digit_count(10) == 3
+ # assert 123.digit_count(2) == 7 # 1111011 in binary
fun digit_count(b: Int): Int
do
+ if b == 10 then return digit_count_base_10
var d: Int # number of digits
var n: Int # current number
# Sign
return d
end
+ # Optimized version for base 10
+ fun digit_count_base_10: Int
+ do
+ var val: Int
+ var result: Int
+ if self < 0 then
+ result = 2
+ val = -self
+ else
+ result = 1
+ val = self
+ end
+ loop
+ if val < 10 then return result
+ if val < 100 then return result+1
+ if val < 1000 then return result+2
+ if val < 10000 then return result+3
+ val = val / 10000
+ result += 4
+ end
+ end
+
# Return the corresponding digit character
- # If 0 <= `self' <= 9, return the corresponding character.
- # If 10 <= `self' <= 36, return the corresponding letter [a..z].
+ # If 0 <= `self` <= 9, return the corresponding character.
+ # assert 5.to_c == '5'
+ # If 10 <= `self` <= 36, return the corresponding letter [a..z].
+ # assert 15.to_c == 'f'
fun to_c: Char
do
assert self >= 0 and self <= 36 # TODO plan for this
end
end
- # Execute 'each' for each integer in [self..last]
- fun enumerate_to(last: Int)
- !each(i: Int)
- do
- var cur = self
- while cur <= last do
- each(cur)
- cur += 1
- end
- end
-
- # Execute 'each' for each integer in [self..after[
- fun enumerate_before(after: Int)
- !each(i: Int)
- do
- var cur = self
- while cur < after do
- each(cur)
- cur += 1
- end
- end
-
# The absolute value of self
+ #
+ # assert (-10).abs == 10
+ # assert 10.abs == 10
+ # assert 0.abs == 0
fun abs: Int
do
if self >= 0
# Native characters.
# Characters are denoted with simple quote.
-# eg. 'a' or '\n'.
+# eg. `'a'` or `'\n'`.
universal Char
super Discrete
redef type OTHER: Char
redef fun object_id is intern
+ redef fun hash do return ascii
redef fun ==(o) is intern
redef fun !=(o) is intern
redef fun output is intern
redef fun >=(i) is intern
redef fun >(i) is intern
- redef fun succ is intern
- redef fun prec is intern
+ redef fun successor(i) is intern
+ redef fun predecessor(i) is intern
redef fun distance(c)
do
end
end
- # If `self' is a digit then return this digit else return -1.
+ # If `self` is a digit then return this digit else return -1.
+ #
+ # assert '5'.to_i == 5
fun to_i: Int
do
else if is_digit then
return self.ascii - '0'.ascii
else
- return self.to_lower.ascii - ('a'.ascii + 10)
+ return self.to_lower.ascii - 'a'.ascii + 10
end
end
# the ascii value of self
+ #
+ # assert 'a'.ascii == 97
+ # assert '\n'.ascii == 10
fun ascii: Int is intern
- redef fun +(i) is intern
- redef fun -(i) is intern
-
# Return the lower case version of self.
# If self is not a letter, then return self
+ #
+ # assert 'A'.to_lower == 'a'
+ # assert 'a'.to_lower == 'a'
+ # assert '$'.to_lower == '$'
fun to_lower: Char
do
if is_upper then
# Return the upper case version of self.
# If self is not a letter, then return self
+ #
+ # assert 'a'.to_upper == 'A'
+ # assert 'A'.to_upper == 'A'
+ # assert '$'.to_upper == '$'
fun to_upper: Char
do
if is_lower then
return self
end
end
-
+
# Is self a digit? (from '0' to '9')
+ #
+ # assert '0'.is_digit == true
+ # assert '9'.is_digit == true
+ # assert 'a'.is_digit == false
fun is_digit : Bool
do
return self >= '0' and self <= '9'
end
-
+
# Is self a lower case letter? (from 'a' to 'z')
+ #
+ # assert 'a'.is_lower == true
+ # assert 'z'.is_lower == true
+ # assert 'A'.is_lower == false
+ # assert '$'.is_lower == false
fun is_lower : Bool
do
return self >= 'a' and self <= 'z'
end
-
+
# Is self a upper case letter? (from 'A' to 'Z')
+ #
+ # assert 'A'.is_upper == true
+ # assert 'A'.is_upper == true
+ # assert 'z'.is_upper == false
+ # assert '$'.is_upper == false
fun is_upper : Bool
do
return self >= 'A' and self <= 'Z'
end
-
+
# Is self a letter? (from 'A' to 'Z' and 'a' to 'z')
+ #
+ # assert 'A'.is_letter == true
+ # assert 'A'.is_letter == true
+ # assert 'z'.is_letter == true
+ # assert '$'.is_letter == false
fun is_letter : Bool
do
return is_lower or is_upper
end
# Pointer classes are used to manipulate extern C structures.
-extern Pointer
+extern class Pointer
+ # Is the address behind this Object at NULL?
+ fun address_is_null: Bool is extern "address_is_null"
+
+ # Free the memory pointed by this pointer
+ fun free is extern "free"
end