HCoop / hcoop / debian / mlton.git / blame
| Commit | Line | Data |
|---|---|---|
| 7f918cf1 CE |
1 | SXML |
| 2 | ==== | |
| 3 | ||
| 4 | <:SXML:> is an <:IntermediateLanguage:>, translated from <:XML:> by | |
| 5 | <:Monomorphise:>, optimized by <:SXMLSimplify:>, and translated by | |
| 6 | <:ClosureConvert:> to <:SSA:>. | |
| 7 | ||
| 8 | == Description == | |
| 9 | ||
| 10 | SXML is a simply-typed version of <:XML:>. | |
| 11 | ||
| 12 | == Implementation == | |
| 13 | ||
| 14 | * <!ViewGitFile(mlton,master,mlton/xml/sxml.sig)> | |
| 15 | * <!ViewGitFile(mlton,master,mlton/xml/sxml.fun)> | |
| 16 | * <!ViewGitFile(mlton,master,mlton/xml/sxml-tree.sig)> | |
| 17 | ||
| 18 | == Type Checking == | |
| 19 | ||
| 20 | <:SXML:> shares the type checker for <:XML:>. | |
| 21 | ||
| 22 | == Details and Notes == | |
| 23 | ||
| 24 | There are only two differences between <:XML:> and <:SXML:>. First, | |
| 25 | <:SXML:> `val`, `fun`, and `datatype` declarations always have an | |
| 26 | empty list of type variables. Second, <:SXML:> variable references | |
| 27 | always have an empty list of type arguments. Constructors uses can | |
| 28 | only have a nonempty list of type arguments if the constructor is a | |
| 29 | primitive. | |
| 30 | ||
| 31 | Although we could rely on the type system to enforce these constraints | |
| 32 | by parameterizing the <:XML:> signature, <:StephenWeeks:> did so in a | |
| 33 | previous version of the compiler, and the software engineering gains | |
| 34 | were not worth the effort. |