diff options
| -rw-r--r-- | doc/manual.tex | 4 | ||||
| -rw-r--r-- | src/urweb.grm | 10 | ||||
| -rw-r--r-- | tests/conargs.ur | 9 |
3 files changed, 20 insertions, 3 deletions
diff --git a/doc/manual.tex b/doc/manual.tex index 2c1cecc2..541dd96b 100644 --- a/doc/manual.tex +++ b/doc/manual.tex @@ -380,7 +380,7 @@ $$\begin{array}{rrcll} &&& \{\kappa\} & \textrm{type-level records} \\ &&& (\kappa\times^+) & \textrm{type-level tuples} \\ &&& X & \textrm{variable} \\ - &&& X \longrightarrow k & \textrm{kind-polymorphic type-level function} \\ + &&& X \longrightarrow \kappa & \textrm{kind-polymorphic type-level function} \\ &&& \_\_ & \textrm{wildcard} \\ &&& (\kappa) & \textrm{explicit precedence} \\ \end{array}$$ @@ -549,6 +549,8 @@ A tuple type $\tau_1 \times \ldots \times \tau_n$ expands to a record type $\{1 In general, several adjacent $\lambda$ forms may be combined into one, and kind and type annotations may be omitted, in which case they are implicitly included as wildcards. More formally, for constructor-level abstractions, we can define a new non-terminal $b ::= x \mid (x :: \kappa) \mid X$ and allow composite abstractions of the form $\lambda b^+ \Rightarrow c$, elaborating into the obvious sequence of one core $\lambda$ per element of $b^+$. +Further, the signature item or declaration syntax $\mt{con} \; x \; b^+ = c$ is shorthand for wrapping of the appropriate $\lambda$s around the righthand side $c$. The $b$ elements may not include $X$, and there may also be an optional $:: \kappa$ before the $=$. + In some contexts, the parser isn't happy with token sequences like $x :: \_$, to indicate a constructor variable of wildcard kind. In such cases, write the second two tokens as $::\hspace{-.05in}\_$, with no intervening spaces. Analogous syntax $:::\hspace{-.05in}\_$ is available for implicit constructor arguments. For any signature item or declaration that defines some entity to be equal to $A$ with classification annotation $B$ (e.g., $\mt{val} \; x : B = A$), $B$ and the preceding colon (or similar punctuation) may be omitted, in which case it is filled in as a wildcard. diff --git a/src/urweb.grm b/src/urweb.grm index d39fbe55..65264cdf 100644 --- a/src/urweb.grm +++ b/src/urweb.grm @@ -706,8 +706,14 @@ sgntm : SIG sgis END (SgnConst sgis, s (SIGleft, ENDright)) sgi : CON SYMBOL DCOLON kind ((SgiConAbs (SYMBOL, kind), s (CONleft, kindright))) | LTYPE SYMBOL ((SgiConAbs (SYMBOL, (KType, s (LTYPEleft, SYMBOLright))), s (LTYPEleft, SYMBOLright))) - | CON SYMBOL EQ cexp ((SgiCon (SYMBOL, NONE, cexp), s (CONleft, cexpright))) - | CON SYMBOL DCOLON kind EQ cexp ((SgiCon (SYMBOL, SOME kind, cexp), s (CONleft, cexpright))) + | CON SYMBOL cargl2 kopt EQ cexp (let + val loc = s (CONleft, cexpright) + + val k = Option.getOpt (kopt, (KWild, loc)) + val (c, k) = cargl2 (cexp, k) + in + (SgiCon (SYMBOL, SOME k, c), loc) + end) | LTYPE SYMBOL EQ cexp ((SgiCon (SYMBOL, SOME (KType, s (LTYPEleft, cexpright)), cexp), s (LTYPEleft, cexpright))) | DATATYPE dtypes ((SgiDatatype dtypes, s (DATATYPEleft, dtypesright))) diff --git a/tests/conargs.ur b/tests/conargs.ur new file mode 100644 index 00000000..310e1246 --- /dev/null +++ b/tests/conargs.ur @@ -0,0 +1,9 @@ +con func a b = a -> b + +signature S = sig + con funcy a b = a -> b +end + +structure M : S = struct + con funcy = func +end |