158 lines
4.2 KiB
Markdown
158 lines
4.2 KiB
Markdown
#Typechecking Notes
|
|
|
|
(cf. cardelli paper)
|
|
|
|
Given a length function def:
|
|
````
|
|
fn length(x) {
|
|
if x.is_null {
|
|
0
|
|
} else {
|
|
succ(length(x.tail))
|
|
}
|
|
}
|
|
````
|
|
Constraints:
|
|
.null: List a -> bool
|
|
.tail: List a -> List a
|
|
0: Nat
|
|
succ: Nat -> Nat
|
|
|
|
|
|
|
|
|
|
# TODO Items
|
|
|
|
-make the REPL more advanced!
|
|
|
|
-Plan of attack:
|
|
-write a visitor pattern for AST
|
|
-convert AST type to including SourceMap'd wrappers (w/ .into())
|
|
-at the same time, amke sure the visitor pattern "skips over" the SourceMap'd stuff
|
|
so it can just care about AST structure
|
|
|
|
- AST : maybe replace the Expression type with "Ascription(TypeName, Box<Expression>) nodes??
|
|
- parser: add a "debug" field to the Parser struct for all debug-related things
|
|
|
|
-scala-style html"dfasfsadf${}" string interpolations!
|
|
|
|
-fuzz test schala
|
|
|
|
-look into Inkwell for LLVM
|
|
|
|
|
|
*A neat idea for pattern matching optimization would be if you could match on one of several things in a list
|
|
ex:
|
|
if x {
|
|
is (comp, LHSPat, RHSPat) if comp in ["==, "<"] -> ...
|
|
}
|
|
|
|
|
|
- https://nshipster.com/never/
|
|
-https://cranelift.readthedocs.io/en/latest/?badge=latest<Paste>
|
|
|
|
-consult http://gluon-lang.org/book/embedding-api.html
|
|
|
|
- if/match playground
|
|
|
|
simple if
|
|
`if x == 1.0 { "a" } else { "b" }`
|
|
|
|
one comparison multiple targets:
|
|
`if x == { 1.0 -> "a", 2.0 -> "b", else -> "c" }`
|
|
|
|
different comparison operators/ method calls:
|
|
`if x { == 1.0 -> "a", eq NaN -> "n", .hella() -> "h", else -> "z" }`
|
|
|
|
pattern matching/introducing bindings:
|
|
`if alice { .age < 18 -> "18", is Person("Alice", age) -> "${age}", else -> "none" }`
|
|
|
|
pattern matching w/ if-let:
|
|
`if person is Person("Alice", age) { "${age}" } else { "nope" }`
|
|
|
|
-https://soc.github.io/languages/unified-condition-syntax syntax:
|
|
|
|
`if <cond-expr>" then <then-expr> else <else-expr>`
|
|
`if <half-expr> \n <rest-expr1> then <result1-expr> \n <rest-expr2> then <result-expr2> else <result3-expr>`
|
|
-and rest-exprs (or "targets") can have 'is' for pattern-matching, actually so can a full cond-expr
|
|
|
|
UNIFIED IF EXPRESSIONS FINAL WORK:
|
|
|
|
basic syntax:
|
|
|
|
`if_expr := if discriminator '{' (guard_expr)* '}'`
|
|
`guard_expr := pattern 'then' block_or_expr'`
|
|
`pattern := rhs | is_pattern`
|
|
`is_pattern := 'is' ???`
|
|
`rhs := expression | ???`
|
|
|
|
|
|
if the only two guard patterns are true and false, then the abbreviated syntax:
|
|
`'if' discriminator 'then' block_or_expr 'else' block_or_expr`
|
|
can replace `'if' discriminator '{' 'true' 'then' block_or_expr; 'false' 'then' block_or_expr '}'`
|
|
|
|
|
|
|
|
|
|
- Next priorities: - get ADTs working, get matches working
|
|
|
|
- inclusive/exclusive range syntax like .. vs ..=
|
|
|
|
- sketch of an idea for the REPL:
|
|
-each compiler pass should be a (procedural?) macro like
|
|
compiler_pass!("parse", dataproducts: ["ast", "parse_tree"], {
|
|
match parsing::parse(INPUT) {
|
|
Ok(
|
|
PASS.add_artifact(
|
|
}
|
|
|
|
-should have an Idris-like `cast To From` function
|
|
|
|
- REPL:
|
|
- want to be able to do things like `:doc Identifier`, and have the language load up these definitions to the REPL
|
|
|
|
|
|
* change 'trait' to 'interface'
|
|
-think about idris-related ideas of multiple implementations of a type for an interface (+ vs * impl for monoids, for preorder/inorder/postorder for Foldable)
|
|
|
|
* Share state between programming languages
|
|
|
|
* idea for Schala - scoped types - be able to define a quick enum type scoped to a function ro something, that only is meant to be used as a quick bespoke interface between two other things
|
|
|
|
* another idea, allow:
|
|
type enum {
|
|
type enum MySubVariant {
|
|
SubVariant1, SubVariant2, etc.
|
|
}
|
|
Variant1(MySubVariant),
|
|
Variant2(...),
|
|
}
|
|
|
|
|
|
|
|
* idea for Schala: both currying *and* default arguments!
|
|
ex. fn a(b: Int, c:Int, d:Int = 1) -> Int
|
|
a(1,2) : Int
|
|
a(1,2,d=2): Int
|
|
a(_,1,3) : Int -> Int
|
|
a(1,2, c=_): Int -> Int
|
|
a(_,_,_) : Int -> Int -> Int -> Int
|
|
|
|
|
|
|
|
|
|
|
|
*Compiler passes architecture
|
|
|
|
-ProgrammingLanguageInterface defines a evaluate_in_repl() and evaluate_no_repl() functions
|
|
-these take in a vec of CompilerPasses
|
|
|
|
struct CompilerPass {
|
|
name: String,
|
|
run: fn(PrevPass) -> NextPass
|
|
}
|
|
|
|
-change "Type...." names in parser.rs to "Anno..." for non-collision with names in typechecking.rs
|
|
|
|
-get rid of code pertaining to compilation specifically, have a more generation notion of "execution type"
|