ref: 4f90a4d919cc5862fd3ecbffc62b94b515dda7d3
parent: 8e01f48956e56db35dfa7d5ce402a400f3478c8b
author: Ori Bernstein <[email protected]>
date: Mon Aug 20 14:12:51 EDT 2012
More docs.
--- a/doc/lang.txt
+++ b/doc/lang.txt
@@ -577,21 +577,75 @@
from the type system perspective into a small set of classes. and define
the constraints that they require.
- num-binop:
+ Type inference in Myrddin operates as a bottom up tree walk,
+ applying the type equations for the operator to its arguments.
+ It begins by initializing all leaf nodes with the most specific
+ known type for them as follows:
+
+ 3.6.1 Types for leaf nodes:
+
+ Variable Type
+ ----------------------
+ var foo $t
+
+ A type variable is the most specific type for a declaration
+ or function without any specified type
+
+ var foo : t t
+
+ If a type is specified, that type is taken for the
+ declaration.
+
+ "asdf" byte[:]
+
+ String literals are byte arrays.
+
+
+ 'a' char
+
+ Char literals are of type 'char'
+
+ true bool
+ false bool
+
+ true/false are boolean literals
+
+ 123 $t::(tcint,tcnum,tctest)
+
+ Integer literals get a fresh type variable of type with
+ the constraints for int-like types.
+
+ 123.1 $t::(tcfloat,tcnum,tctest)
+
+ Float literals get a fresh type variable of type with
+ the constraints for float-like types.
+
+ {a,b:t; } ($a,t -> $b)+
+ Function literals get the most specific type that can
+ be determined by their signature.
+
+
+ num-binop:
+
+ - * / %
+= -= *= /= %
- num-unary:
- - +
- int-binop:
- | & ^ << >>
- |= &= ^= <<= >>
- int-unary:
- ~ ++ --
+ Number binops require the constraint 'tcnum' for both the
+
+ num-unary:
+ - +
+ Number binops require the constraint 'tcnum'.
- bool-binop:
- || && == !=
- < <= > >=
+ int-binop:
+ | & ^ << >>
+ |= &= ^= <<= >>
+ int-unary:
+ ~ ++ --
+
+ bool-binop:
+ || && == !=
+ < <= > >=
3.7. Packages and Uses: