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| -rw-r--r-- | README.md | 2 | ||||
| -rw-r--r-- | TypeAnalysis.md | 38 | ||||
| -rw-r--r-- | chapter23/README.md | 4 |
3 files changed, 34 insertions, 10 deletions
@@ -66,4 +66,4 @@ The Simple language is styled after a subset of C or Java. * [Chapter 20](chapter20/README.md): Graph Coloring Register Allocation * [Chapter 21](chapter21/README.md): Instruction Encodings & ELF * [Chapter 22](chapter22/README.md): A Simple Hello, World! -* [Chapter 23](chapter23/README.md): Strings, Methods +* [Chapter 23](chapter23/README.md): Methods and Types Revisited diff --git a/TypeAnalysis.md b/TypeAnalysis.md index fe79de68..ee187cdf 100644 --- a/TypeAnalysis.md +++ b/TypeAnalysis.md @@ -179,6 +179,9 @@ be interleaved with other optimizations as long as those optimizations do not lo any type information - and indeed this is the mode the C2 compiler has been running in since 1997. +First appears in [Simple chapter02](https://github.com/SeaOfNodes/Simple/tree/main/chapter02): +the pessimistic treatment during parsing with the simple integer lattice. + ## More Lattices @@ -190,13 +193,18 @@ language types like `i32`, `i64`, `u16`, `u8`, `byte` and so forth. [Lattice2](./docs/lattice_i2.svg) <img src = ./docs/lattice_i2.svg> +First appears in [Simple chapter14](https://github.com/SeaOfNodes/Simple/tree/main/chapter14). + + Parallel to the integer lattice we add a IEEE 754 floating point lattice, which allows us to track FP constants, e.g. `0.` or `pi`. We track both 32b and 64b values, and can observe that the 32b ones are a strict subset of the 64b ones. - [Lattice3](./docs/lattice_if.svg) <img src = ./docs/lattice_if.svg> +First appears in [Simple chapter12](https://github.com/SeaOfNodes/Simple/tree/main/chapter12). + + Now we add more "inner" lattices, the key being that inner lattices do not themselves contain another lattice element. For example a hypothetical sub-word FP format: @@ -214,6 +222,8 @@ if test: [Lattice5](./docs/lattice_iffc.svg) <img src = ./docs/lattice_iffc.svg> +First appears in [Simple chapter04](https://github.com/SeaOfNodes/Simple/tree/main/chapter04). + Hopefully it is clear how to add another sub-lattice that itself is symmetric, complete and ranked. @@ -282,6 +292,10 @@ but we will shortly use them in building structs and functions. [Lattice6](./docs/lattice_iffct.svg) <img src = ./docs/lattice_iffct.svg> +First appears in [Simple chapter10](https://github.com/SeaOfNodes/Simple/tree/main/chapter10) +along with structs and pointers. + + ## Structs We implement *struct types* as a tuple with named fields: @@ -310,6 +324,9 @@ desired semantics, as well as the normal *meet* on the field type. I am not covering here how to initialize struct members, or the syntax for declaring structs or traits - just the resulting types. +First appears in [Simple chapter10](https://github.com/SeaOfNodes/Simple/tree/main/chapter10) +along with tuples and pointers. + ## Pointers @@ -341,6 +358,8 @@ Here the load to fetch the `makeSound` method fails during error reporting; in Simple this is just a `LoadNode` which has an error check against its pointer input being possibly `null`. +First appears in [Simple chapter10](https://github.com/SeaOfNodes/Simple/tree/main/chapter10), +along with structs and tuples. ### Equivalence Class Aliasing @@ -368,7 +387,6 @@ into e.g. GPU memory (probably as another alias class), or pointers to uninitialized memory, or destructed memory. - ## Functions Functions have argument types and some return types (often just 1). We'll @@ -426,6 +444,8 @@ build a reasonably accurate Call Graph: the set of function types arriving at a site dictates which functions might be called here. More on this in the [Call Graph](#call-graph) section. +First appears in [Simple chapter18](https://github.com/SeaOfNodes/Simple/tree/main/chapter18). + ## Type Sugar And All The Rest @@ -490,6 +510,8 @@ This is the general way *methods* are handled: they are reduced to function- typed fields in a struct, and then the existing *meet* and *join* operations are well defined. +First appears in [Simple chapter23](https://github.com/SeaOfNodes/Simple/tree/main/chapter23). + ## Subclassing @@ -531,10 +553,12 @@ makeSound:[#1]{Pet->String}]` which *isa* `Cat`, and similar for `dog` and `dog.isa(Dog)` and `Dog.isa(Pet)`. -Subclassing generally means supporting *virtual* calls, so here I will show a typical virtual call execution strategy; other strategies are possible (e.g. *inline caches* in a some VM). In this case, the -optimized version of methods means moving from the instance to the class, then -doing the field lookup to get a function... then calling it. This is the same -sequence as done by both C++ and Java. +Subclassing generally means supporting *virtual* calls, so here I will show a +typical virtual call execution strategy; other strategies are possible +(e.g. *inline caches* in a some VM). In this case, the optimized version of +methods means moving from the instance to the class, then doing the field +lookup to get a function... then calling it. This is the same sequence as done +by both C++ and Java. `(rand() ? cat : dog).makeSound()` @@ -690,7 +714,7 @@ StealthCow and Duck is: And since this is not equal to a `Duck`, the `isa` fails, the *type cast* will report an error. -### A Equatable Trait Example +### An Equatable Trait Example Let's make a concrete working example with a trait `Equals`; here is the type for `Equals`: diff --git a/chapter23/README.md b/chapter23/README.md index 946853f7..cac55253 100644 --- a/chapter23/README.md +++ b/chapter23/README.md @@ -54,10 +54,10 @@ used for type-checking, so sharper types means we allow more valid programs. **Why Cyclic Types Now**? Because we hit them as soon as we allow a function definition inside of a struct which takes the struct as an argument, -i.e. *methods* talking a *self* argument. +i.e. *methods* taking a *self* argument. Lets look at our `String.indexOf` example above. Here we define a `String` -class with an `indexOf` method; a hiddent argument string `self` is passed in +with an `indexOf` method; a hidden argument string `self` is passed in and searched. What is the type of `struct String`? `struct String { u8[~] buf; { String self, u8 c -> int } indexOf; }` |