ref: 1f76d9d4cf660c5fb66d406c5488ce4d734d8e25
parent: b88feaef76f1c93fc3e0c4125a8bbb2f536878e3
author: henesy <henesy.dev@gmail.com>
date: Mon Mar 11 13:39:03 EDT 2019
more work on generics
--- a/Generics/README.md
+++ b/Generics/README.md
@@ -1,22 +1,78 @@
# Generics
+Limbo supports polymorphic types as well as a form of pseudo-unions and pseudo-interfaces as per C and Go respectively.
-
Warning: This is an example about an undocumented feature of Limbo. All assertions or explanations provided are considered conjecture until proven otherwise.
## Source
-###
+### generics.b:17,21
+
+
+### generics.b:23,32
+
+
+
+### generics.b:34,44
+
+
+
+### generics.b:46,50
+
+
+
+### generics.b:56,63
+
+
+
+`.ws()` is defined at: generics.b:103,109
+
+### generics.b:65,69
+
+
+
+### generics.b:71,83
+
+
+
+`ismember()` is defined at: generics.b:132,144
+
+`.eq()` is defined at: generics.b:111,114
+
+### generics.b:85,87
+
+
+
+`rev()` is defined at: generics.b:154,161
+
+### generics.b:89,98
+
+
+
+`pair()` is defined at: generics.b:146,152
+
## Demo
+ ; generics
+ Type something: asdf
+ Broke on 'a'
+ 5
+ Five
+ Found 9!
+ Head was: :(
+ Head is: ☺
+ Head of plist: ( hello, { :(, 7 } )
+ ;
+
## Exercises
-- Can you find a way to make the eq() function do a deep comparison of Int's?
+- Can you find a way to make the `eq()` function do a deep comparison of `Int`'s?
- Try removing the `.String` from the `words` definition, what happens?
- Try removing `ref anywhere, see what happens.
## References
-- https://github.com/caerwynj/inferno-lab/blob/master/27/sexprs.b
- https://github.com/caerwynj/inferno-lab/blob/master/78/README.md
+- https://github.com/caerwynj/inferno-lab/blob/master/27/sexprs.b
+- /appl/lib/lists.b
--- a/Generics/generics.b
+++ b/Generics/generics.b
@@ -73,9 +73,9 @@
smiley := "☺";
frowny := ":(";
+ # Format is: Adt[Type].PickTag(fields...)
sword := ref Word[Int].String(Int(9), smiley);
- # Format is: Adt[Type].PickTag(fields...)
words = sword :: words;
words = ref Word[Int].String(Int(7), frowny) :: words;
@@ -82,6 +82,21 @@
if(ismember(sword, words))
print("Found %d!\n", sword.w.d);
+ backwords := rev(words);
+
+ print("Head was: %s\nHead is: %s\n", (hd words).s, (hd backwords).s);
+
+ strings: list of string;
+ strings = "hi" :: strings;
+ strings = "hello" :: strings;
+
+ # plist is a `list of (string, ref Word.String)`
+ plist := pair(strings, words);
+
+ (str, word) := hd plist;
+
+ print("Head of plist: ( %s, { %s, %d } )\n", str, word.s, word.w.d);
+
exit;
}
@@ -117,7 +132,8 @@
# Checks if x is a member of l
ismember[T](x: T, l: list of T): int
for {
- T => eq: fn(a, b: T): int;
+ T =>
+ eq: fn(a, b: T): int;
}
{
for(; l != nil; l = tl l)