Revising manual through end of Section 6

1 files changed, 28 insertions, 15 deletions

diff --git a/doc/manual.tex b/doc/manual.tex
index 3f549c5b..368e3024 100644
--- a/doc/manual.tex
+++ b/doc/manual.tex
@@ -166,7 +166,7 @@ urweb -timing P
 
 \section{Ur Syntax}
 
-In this section, we describe the syntax of Ur, deferring to a later section discussion of most of the syntax specific to SQL and XML.  The sole exceptions are the declaration forms for tables, sequences, and cookies.
+In this section, we describe the syntax of Ur, deferring to a later section discussion of most of the syntax specific to SQL and XML.  The sole exceptions are the declaration forms for relations, cookies, and styles.
 
 \subsection{Lexical Conventions}
 
@@ -343,8 +343,10 @@ $$\begin{array}{rrcll}
   &&& \mt{constraint} \; c \sim c & \textrm{record disjointness constraint} \\
   &&& \mt{open} \; \mt{constraints} \; M & \textrm{inclusion of just the constraints from a module} \\
   &&& \mt{table} \; x : c & \textrm{SQL table} \\
+  &&& \mt{view} \; x : c & \textrm{SQL view} \\
   &&& \mt{sequence} \; x & \textrm{SQL sequence} \\
   &&& \mt{cookie} \; x : \tau & \textrm{HTTP cookie} \\
+  &&& \mt{style} \; x : \tau & \textrm{CSS class} \\
   &&& \mt{class} \; x :: \kappa = c & \textrm{concrete constructor class} \\
   \\
   \textrm{Modules} & M &::=& \mt{struct} \; d^* \; \mt{end} & \textrm{constant} \\
@@ -356,6 +358,8 @@ $$\begin{array}{rrcll}
 
 There are two kinds of Ur files.  A file named $M\texttt{.ur}$ is an \emph{implementation file}, and it should contain a sequence of declarations $d^*$.  A file named $M\texttt{.urs}$ is an \emph{interface file}; it must always have a matching $M\texttt{.ur}$ and should contain a sequence of signature items $s^*$.  When both files are present, the overall effect is the same as a monolithic declaration $\mt{structure} \; M : \mt{sig} \; s^* \; \mt{end} = \mt{struct} \; d^* \; \mt{end}$.  When no interface file is included, the overall effect is similar, with a signature for module $M$ being inferred rather than just checked against an interface.
 
+We omit some extra possibilities in $\mt{table}$ syntax, deferring them to Section \ref{tables}.
+
 \subsection{Shorthands}
 
 There are a variety of derived syntactic forms that elaborate into the core syntax from the last subsection.  We will present the additional forms roughly following the order in which we presented the constructs that they elaborate into.
@@ -392,7 +396,7 @@ The syntax $\mt{if} \; e \; \mt{then} \; e_1 \; \mt{else} \; e_2$ expands to $\m
 
 There are infix operator syntaxes for a number of functions defined in the $\mt{Basis}$ module.  There is $=$ for $\mt{eq}$, $\neq$ for $\mt{neq}$, $-$ for $\mt{neg}$ (as a prefix operator) and $\mt{minus}$, $+$ for $\mt{plus}$, $\times$ for $\mt{times}$, $/$ for $\mt{div}$, $\%$ for $\mt{mod}$, $<$ for $\mt{lt}$, $\leq$ for $\mt{le}$, $>$ for $\mt{gt}$, and $\geq$ for $\mt{ge}$.
 
-A signature item $\mt{table} \; x : c$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{sql\_table} \; c$.  $\mt{sequence} \; x$ is short for $\mt{val} \; x : \mt{Basis}.\mt{sql\_sequence}$, and $\mt{cookie} \; x : \tau$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{http\_cookie} \; \tau$.
+A signature item $\mt{table} \; x : c$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{sql\_table} \; c \; []$.  $\mt{view} \; x : c$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{sql\_view} \; c$, $\mt{sequence} \; x$ is short for $\mt{val} \; x : \mt{Basis}.\mt{sql\_sequence}$.  $\mt{cookie} \; x : \tau$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{http\_cookie} \; \tau$, and $\mt{style} \; x$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{css\_class}$.
 
 
 \section{Static Semantics}
@@ -790,17 +794,22 @@ $$\infer{\Gamma \vdash \mt{constraint} \; c_1 \sim c_2 \leadsto \Gamma}{
   \Gamma \vdash M : \mt{sig} \; \overline{s} \; \mt{end}
 }$$
 
-$$\infer{\Gamma \vdash \mt{table} \; x : c \leadsto \Gamma, x : \mt{Basis}.\mt{sql\_table} \; c}{
+$$\infer{\Gamma \vdash \mt{table} \; x : c \leadsto \Gamma, x : \mt{Basis}.\mt{sql\_table} \; c \; []}{
   \Gamma \vdash c :: \{\mt{Type}\}
 }
-\quad \infer{\Gamma \vdash \mt{sequence} \; x \leadsto \Gamma, x : \mt{Basis}.\mt{sql\_sequence}}{}$$
+\quad \infer{\Gamma \vdash \mt{view} \; x : c \leadsto \Gamma, x : \mt{Basis}.\mt{sql\_view} \; c}{
+  \Gamma \vdash c :: \{\mt{Type}\}
+}$$
+
+$$\infer{\Gamma \vdash \mt{sequence} \; x \leadsto \Gamma, x : \mt{Basis}.\mt{sql\_sequence}}{}$$
 
 $$\infer{\Gamma \vdash \mt{cookie} \; x : \tau \leadsto \Gamma, x : \mt{Basis}.\mt{http\_cookie} \; \tau}{
   \Gamma \vdash \tau :: \mt{Type}
-}$$
+}
+\quad \infer{\Gamma \vdash \mt{style} \; x \leadsto \Gamma, x : \mt{Basis}.\mt{css\_class}}{}$$
 
-$$\infer{\Gamma \vdash \mt{class} \; x :: \kappa = c \leadsto \Gamma, x :: \kappa \to \mt{Type} = c}{
-  \Gamma \vdash c :: \kappa \to \mt{Type}
+$$\infer{\Gamma \vdash \mt{class} \; x :: \kappa = c \leadsto \Gamma, x :: \kappa = c}{
+  \Gamma \vdash c :: \kappa
 }$$
 
 $$\infer{\overline{y}; x; \Gamma \vdash \cdot \leadsto \Gamma}{}
@@ -856,10 +865,10 @@ $$\infer{\Gamma \vdash \mt{constraint} \; c_1 \sim c_2 \leadsto \Gamma, c_1 \sim
   & \Gamma \vdash c_2 :: \{\kappa\}
 }$$
 
-$$\infer{\Gamma \vdash \mt{class} \; x :: \kappa = c \leadsto \Gamma, x :: \kappa \to \mt{Type} = c}{
-  \Gamma \vdash c :: \kappa \to \mt{Type}
+$$\infer{\Gamma \vdash \mt{class} \; x :: \kappa = c \leadsto \Gamma, x :: \kappa = c}{
+  \Gamma \vdash c :: \kappa
 }
-\quad \infer{\Gamma \vdash \mt{class} \; x :: \kappa \leadsto \Gamma, x :: \kappa \to \mt{Type}}{}$$
+\quad \infer{\Gamma \vdash \mt{class} \; x :: \kappa \leadsto \Gamma, x :: \kappa}{}$$
 
 \subsection{Signature Compatibility}
 
@@ -919,13 +928,13 @@ $$\infer{\Gamma \vdash \mt{datatype} \; x = \mt{datatype} \; M.z \leq \mt{con} \
   & \mt{proj}(M, \overline{s}, \mt{datatype} \; z) = (\overline{y}, \overline{dc})
 }$$
 
-$$\infer{\Gamma \vdash \mt{class} \; x :: \kappa \leq \mt{con} \; x :: \kappa \to \mt{Type}}{}
-\quad \infer{\Gamma \vdash \mt{class} \; x :: \kappa = c \leq \mt{con} \; x :: \kappa \to \mt{Type}}{}$$
+$$\infer{\Gamma \vdash \mt{class} \; x :: \kappa \leq \mt{con} \; x :: \kappa}{}
+\quad \infer{\Gamma \vdash \mt{class} \; x :: \kappa = c \leq \mt{con} \; x :: \kappa}{}$$
 
 $$\infer{\Gamma \vdash \mt{con} \; x :: \kappa = c_1 \leq \mt{con} \; x :: \mt{\kappa} = c_2}{
   \Gamma \vdash c_1 \equiv c_2
 }
-\quad \infer{\Gamma \vdash \mt{class} \; x :: \kappa = c_1 \leq \mt{con} \; x :: \kappa \to \mt{Type} = c_2}{
+\quad \infer{\Gamma \vdash \mt{class} \; x :: \kappa = c_1 \leq \mt{con} \; x :: \kappa = c_2}{
   \Gamma \vdash c_1 \equiv c_2
 }$$
 
@@ -1019,8 +1028,10 @@ $$\infer{\Gamma \vdash M_1(M_2) : [X \mapsto M_2]S_2}{
   \mt{sigOf}(\mt{constraint} \; c_1 \sim c_2) &=& \mt{constraint} \; c_1 \sim c_2 \\
   \mt{sigOf}(\mt{open} \; \mt{constraints} \; M) &=& \cdot \\
   \mt{sigOf}(\mt{table} \; x : c) &=& \mt{table} \; x : c \\
+  \mt{sigOf}(\mt{view} \; x : c) &=& \mt{view} \; x : c \\
   \mt{sigOf}(\mt{sequence} \; x) &=& \mt{sequence} \; x \\
   \mt{sigOf}(\mt{cookie} \; x : \tau) &=& \mt{cookie} \; x : \tau \\
+  \mt{sigOf}(\mt{style} \; x) &=& \mt{style} \; x \\
   \mt{sigOf}(\mt{class} \; x :: \kappa = c) &=& \mt{class} \; x :: \kappa = c \\
 \end{eqnarray*}
 \begin{eqnarray*}
@@ -1098,9 +1109,9 @@ The type inference engine tries to take advantage of the algebraic rules governi
 
 \subsection{\label{typeclasses}Constructor Classes}
 
-Ur includes a constructor class facility inspired by Haskell's.  The current version is very rudimentary, only supporting instances for particular constructors built up from abstract constructors and datatypes and type-level application.
+Ur includes a constructor class facility inspired by Haskell's.  The current version is experimental, with very general Prolog-like facilities that can lead to compile-time non-termination.
 
-Constructor classes are integrated with the module system.  A constructor class of kind $\kappa$ is just a constructor of kind $\kappa \to \mt{Type}$.  By marking such a constructor $c$ as a constructor class, the programmer instructs the type inference engine to, in each scope, record all values of types $c \; c'$ as \emph{instances}.  Any function argument whose type is of such a form is treated as implicit, to be determined by examining the current instance database.
+Constructor classes are integrated with the module system.  A constructor class of kind $\kappa$ is just a constructor of kind $\kappa$.  By marking such a constructor $c$ as a constructor class, the programmer instructs the type inference engine to, in each scope, record all values of types $c \; c_1 \; \ldots \; c_n$ as \emph{instances}.  Any function argument whose type is of such a form is treated as implicit, to be determined by examining the current instance database.
 
 The ``dictionary encoding'' often used in Haskell implementations is made explicit in Ur.  Constructor class instances are just properly-typed values, and they can also be considered as ``proofs'' of membership in the class.  In some cases, it is useful to pass these proofs around explicitly.  An underscore written where a proof is expected will also be inferred, if possible, from the current instance database.
 
@@ -1195,6 +1206,8 @@ $$\begin{array}{l}
   \mt{con} \; \mt{sql\_table} :: \{\mt{Type}\} \to \mt{Type}
 \end{array}$$
 
+\subsubsection{\label{tables}Tables}
+
 \subsubsection{Queries}
 
 A final query is constructed via the $\mt{sql\_query}$ function.  Constructor arguments respectively specify the table fields we select (as records mapping tables to the subsets of their fields that we choose) and the (always named) extra expressions that we select.