Add concept-index entries to docs, plus fix a few minor nits.

doc/rust.texi

@@ -207,6 +207,7 @@ receiver side.
 
 @sp 1
 @item Predictable native code, simple runtime
+@cindex DWARF
 
 The meaning and cost of every operation within a Rust program is intended to
 be easy to model for the reader. The code should not ``surprise'' the
@@ -299,9 +300,10 @@ Boxed immutable values are reference-counted and have a deterministic
 destruction order: top-down, immediately upon release of the last live
 reference.
 
-State values can refer to immutable values, but not vice-versa. Rust therefore
+State values can refer to non-state values, but not vice-versa. Rust
-encourages the programmer to write in a style that consists primarily of
+therefore encourages the programmer to write in a style that consists
-immutable types, but also permits limited, local (per-task) mutability.
+primarily of immutable types, but also permits limited, local
+(per-task) mutability.
 
 @sp 1
 @item Stack-based iterators
@@ -437,7 +439,7 @@ Every storage slot in a Rust frame participates in not only a conventional
 structural static type system, describing the interpretation of memory in the
 slot, but also a @emph{typestate} system. The static typestates of a program
 describe the set of @emph{pure, dynamic predicates} that provably hold over
-some set of slots, at each point in the program's control flow graph within
+some set of slots, at each point in the program's control-flow graph within
 each frame. The static calculation of the typestates of a program is a
 function-local dataflow problem, and handles user-defined predicates in a
 similar fashion to the way the type system permits user-defined types.
@@ -573,6 +575,8 @@ Additional specific influences can be seen from the following languages:
 @node    Ref.Lex
 @section Ref.Lex
 @c * Ref.Lex::                     Lexical structure.
+@cindex Lexical structure
+@cindex Token
 
 The lexical structure of a Rust source file or crate file is defined in terms
 of Unicode character codes and character properties.
@@ -621,6 +625,7 @@ token or a syntactic extension token.
 @node       Ref.Lex.Ident
 @subsection Ref.Lex.Ident
 @c * Ref.Lex.Ident::             Identifier tokens.
+@cindex Identifier token
 
 Identifiers follow the pattern of C identifiers: they begin with a
 @emph{letter} or @emph{underscore}, and continue with any combination of
@@ -640,6 +645,7 @@ A @dfn{decimal digit} is a character in the range U+0030-U+0039
 @c * Ref.Lex.Key::                Keyword tokens.
 
 The keywords are:
+@cindex Keywords
 
 @sp 2
 
@@ -719,6 +725,11 @@ The keywords are:
 @node       Ref.Lex.Num
 @subsection Ref.Lex.Num
 @c * Ref.Lex.Num::                 Numeric tokens.
+@cindex Number token
+@cindex Hex token
+@cindex Decimal token
+@cindex Binary token
+@cindex Floating-point token
 
 A @dfn{number literal} is either an @emph{integer literal} or a
 @emph{floating-point literal}.
@@ -740,7 +751,7 @@ and @emph{underscores}.
 @end enumerate
 
 @sp 1
-A @dfn{floating point literal} has one of two forms:
+A @dfn{floating-point literal} has one of two forms:
 @enumerate
 @item Two @emph{decimal literals} separated by a period
 character U+002E ('.'), with an optional @emph{exponent} trailing after the
@@ -765,6 +776,10 @@ A @dfn{sign character} is either U+002B or U+002D (@code{'+'} or @code{'-'}).
 @node       Ref.Lex.Text
 @subsection Ref.Lex.Text
 @c * Ref.Lex.Key::                 String and character tokens.
+@cindex String token
+@cindex Character token
+@cindex Escape sequence
+@cindex Unicode
 
 A @dfn{character literal} is a single Unicode character enclosed within two
 U+0027 (single-quote) characters, with the exception of U+0027 itself, which
@@ -812,6 +827,9 @@ region). @xref{Ref.Comp.Syntax}.
 @subsection Ref.Lex.Sym
 @c * Ref.Lex.Sym::                 Special symbol tokens.
 
+@cindex Symbol
+@cindex Operator
+
 The special symbols are:
 
 @sp 2
@@ -877,6 +895,9 @@ The special symbols are:
 @node    Ref.Path
 @section Ref.Path
 @c * Ref.Path::               References to slots and items.
+@cindex Names of items or slots
+@cindex Path name
+@cindex Type parameters
 
 A @dfn{path} is a ubiquitous syntactic form in Rust that deserves special
 attention. A path denotes a slot or an
@@ -943,12 +964,14 @@ x.y.(1 + v).z;
 @section Ref.Gram
 @c * Ref.Gram::                    Grammar.
 
-@emph{TODO: LL(1), it reads like C, Alef and bits of Napier; formalize here}.
+@emph{TODO: mostly LL(1), it reads like C, Alef and bits of Napier;
+formalize here}.
 
 @page
 @node    Ref.Comp
 @section Ref.Comp
 @c * Ref.Comp::                    Compilation and component model.
+@cindex Compilation model
 
 Rust is a @emph{compiled} language. Its semantics are divided along a
 @emph{phase distinction} between compile-time and run-time. Those semantic
@@ -970,6 +993,7 @@ successful produces a single crate in executable form.
 @node       Ref.Comp.Crate
 @subsection Ref.Comp.Crate
 @c * Ref.Comp.Crate::              Units of compilation and linking.
+@cindex Crate
 
 A @dfn{crate} is a unit of compilation and linking, as well as versioning,
 distribution and runtime loading. Crates are defined by @emph{crate source
@@ -1059,6 +1083,7 @@ mod bar @{
 
 @node       Ref.Comp.Meta
 @subsection Ref.Comp.Meta
+@cindex Metadata, in crates
 
 In a crate, a @code{meta} directive associates free form key-value metadata
 with the crate. This metadata can, in turn, be used in providing partial
@@ -1070,6 +1095,7 @@ Alternatively, metadata can serve as a simple form of documentation.
 @node          Ref.Comp.Syntax
 @subsection    Ref.Comp.Syntax
 @c * Ref.Comp.Syntax::        Syntax extension.
+@cindex Syntax extension
 
 Rust provides a notation for @dfn{syntax extension}. The notation is a marked
 syntactic form that can appear as an expression, statement or item in the body
@@ -1118,6 +1144,9 @@ let bool matched = re.match(pattern, s);
 @node    Ref.Mem
 @section Ref.Mem
 @c * Ref.Mem::                     Semantic model of memory.
+@cindex Memory model
+@cindex Box
+@cindex Slot
 
 A Rust task's memory consists of a static set of @emph{items}, a set of tasks
 each with its own @emph{stack}, and a @emph{heap}. Immutable portions of the
@@ -1137,6 +1166,11 @@ consist of @emph{boxes}.
 @node       Ref.Mem.Alloc
 @subsection Ref.Mem.Alloc
 @c * Ref.Mem.Alloc::               Memory allocation model.
+@cindex Item
+@cindex Stack
+@cindex Heap
+@cindex Shared box
+@cindex Task-local box
 
 The @dfn{items} of a program are those functions, iterators, objects, modules
 and types that have their value calculated at compile-time and stored uniquely
@@ -1169,6 +1203,7 @@ execution of other tasks.
 @node       Ref.Mem.Own
 @subsection Ref.Mem.Own
 @c * Ref.Mem.Own::                 Memory ownership model.
+@cindex Ownership
 
 A task @emph{owns} all the @emph{stack-local} slot allocations in its stack
 and @emph{task-local} boxes accessible from its stack. A task @emph{shares}
@@ -1191,6 +1226,10 @@ references to any boxes.
 @node       Ref.Mem.Slot
 @subsection Ref.Mem.Slot
 @c * Ref.Mem.Slot::                Stack memory model.
+@cindex Stack
+@cindex Slot
+@cindex Local slot
+@cindex Alias slot
 
 A task's stack contains slots.
 
@@ -1238,6 +1277,8 @@ fn incr(& mutable int i) @{
 @node       Ref.Mem.Box
 @subsection Ref.Mem.Box
 @c * Ref.Mem.Box::                 Heap memory model.
+@cindex Box
+@cindex Dereference operator
 
 A @dfn{box} is a reference to a reference-counted heap allocation holding
 another value.
@@ -1293,6 +1334,9 @@ fn main() @{
 @node       Ref.Mem.Acct
 @subsection Ref.Mem.Acct
 @c * Ref.Mem.Acct::                Memory accounting model.
+@cindex Domain
+@cindex Accounting
+@cindex Memory budget
 
 Every task belongs to a domain, and that domain tracks the amount of memory
 allocated and not yet released by tasks within it. @xref{Ref.Task.Dom}. Each
@@ -1315,6 +1359,8 @@ cost is transferred to the receiving domain.
 @node    Ref.Task
 @section Ref.Task
 @c * Ref.Task::                    Semantic model of tasks.
+@cindex Task
+@cindex Process
 
 An executing Rust program consists of a tree of tasks. A Rust @dfn{task}
 consists of an entry function, a stack, a set of outgoing communication
@@ -1339,6 +1385,14 @@ operating-system processes.
 @subsection Ref.Task.Comm
 @c * Ref.Task.Comm::               Inter-task communication.
 
+@cindex Communication
+@cindex Port
+@cindex Channel
+@cindex Message passing
+@cindex Send statement
+@cindex Receive statement
+@cindex Flush statement
+
 With the exception of @emph{unsafe} constructs, Rust tasks are isolated from
 interfering with one another's memory directly. Instead of manipulating shared
 storage, Rust tasks communicate with one another using a typed, asynchronous,
@@ -1393,6 +1447,15 @@ operator is @code{<-}. @xref{Ref.Stmt.Recv}.
 @subsection Ref.Task.Life
 @c * Ref.Task.Life::               Task lifecycle and state transitions.
 
+@cindex Lifecycle of task
+@cindex Scheduling
+@cindex Running, task state
+@cindex Blocked, task state
+@cindex Failing, task state
+@cindex Dead, task state
+@cindex Soft failure
+@cindex Hard failure
+
 The @dfn{lifecycle} of a task consists of a finite set of states and events
 that cause transitions between the states. The lifecycle states of a task are:
 
@@ -1442,6 +1505,10 @@ reclamation when the last reference to it drops.
 @subsection Ref.Task.Dom
 @c * Ref.Task.Dom::                Task domains
 
+@cindex Domain
+@cindex Process
+@cindex Thread
+
 Every task belongs to a domain. A @dfn{domain} is a structure that owns tasks,
 schedules tasks, tracks memory allocation within tasks and manages access to
 runtime services on behalf of tasks.
@@ -1463,6 +1530,10 @@ domain.
 @subsection Ref.Task.Sched
 @c * Ref.Task.Sched::              Task scheduling model.
 
+@cindex Scheduling
+@cindex Preemption
+@cindex Yielding control
+
 Every task is @emph{scheduled} within its domain. @xref{Ref.Task.Dom}. The
 currently scheduled task is given a finite @emph{time slice} in which to
 execute, after which it is @emph{descheduled} at a loop-edge or similar
@@ -1478,6 +1549,10 @@ deschedules the task.
 @section Ref.Item
 @c * Ref.Item::               The components of a module.
 
+@cindex Item
+@cindex Type parameters
+@cindex Module item
+
 An @dfn{item} is a component of a module. Items are entirely determined at
 compile-time, remain constant during execution, and may reside in read-only
 memory.
@@ -1516,6 +1591,11 @@ are no general parametric types.
 @subsection Ref.Item.Mod
 @c * Ref.Item.Mod::           Items defining sub-modules.
 
+@cindex Module item
+@cindex Importing names
+@cindex Exporting names
+@cindex Visibility control
+
 A @dfn{module item} contains declarations of other @emph{items}. The items
 within a module may be functions, modules, objects or types. These
 declarations have both static and dynamic interpretation. The purpose of a
@@ -1553,6 +1633,9 @@ and outside of it.
 @subsubsection Ref.Item.Mod.Import
 @c * Ref.Item.Mod.Import::     Declarations for module-local synonyms.
 
+@cindex Importing names
+@cindex Visibility control
+
 An @dfn{import declaration} creates one or more local name bindings synonymous
 with some other name. Usually an import declaration is used to shorten the
 path required to refer to a module item.
@@ -1575,6 +1658,9 @@ fn main() @{
 @subsubsection Ref.Item.Mod.Export
 @c * Ref.Item.Mod.Import::     Declarations for restricting visibility.
 
+@cindex Exporting names
+@cindex Visibility control
+
 An @dfn{export declaration} restricts the set of local declarations within a
 module that can be accessed from code outside the module. By default, all
 local declarations in a module are exported. If a module contains an export
@@ -1606,6 +1692,11 @@ fn main() @{
 @node       Ref.Item.Fn
 @subsection Ref.Item.Fn
 @c * Ref.Item.Fn::            Items defining functions.
+@cindex Functions
+@cindex Slots, function input and output
+@cindex Effect of a function
+@cindex Predicate
+
 
 A @dfn{function item} defines a sequence of statements associated with a name
 and a set of parameters. Functions are declared with the keyword
@@ -1642,6 +1733,11 @@ fn add(int x, int y) -> int @{
 @subsection    Ref.Item.Iter
 @c * Ref.Item.Iter::          Items defining iterators.
 
+@cindex Iterators
+@cindex Put statement
+@cindex Put each statement
+@cindex Foreach statement
+
 Iterators are function-like items that can @code{put} multiple values during
 their execution before returning or tail-calling.
 
@@ -1679,6 +1775,8 @@ for each (int x = range(0,100)) @{
 @node       Ref.Item.Obj
 @subsection Ref.Item.Obj
 @c * Ref.Item.Obj::          Items defining objects.
+@cindex Objects
+@cindex Object constructors
 
 An @dfn{object item} defines the @emph{state} and @emph{methods} of a set of
 @emph{object values}. Object values have object types.  @xref{Ref.Type.Obj}.
@@ -1710,6 +1808,7 @@ check (c.get() == 3);
 @node       Ref.Item.Type
 @subsection Ref.Item.Type
 @c * Ref.Item.Type::          Items defining the types of values and slots.
+@cindex Types
 
 A @dfn{type} defines an @emph{interpretation} of a value in
 memory. @xref{Ref.Type}. Types are declared with the keyword @code{type}. A
@@ -1738,6 +1837,7 @@ restricted form of @code{tag} type. @xref{Ref.Type.Tag}.
 @page
 @node    Ref.Type
 @section Ref.Type
+@cindex Types
 
 Every slot and value in a Rust program has a type. The @dfn{type} of a
 @emph{value} defines the interpretation of the memory holding it. The type of
@@ -1773,6 +1873,10 @@ Rust; they cannot be used as user-defined identifiers in any context.
 
 @node       Ref.Type.Any
 @subsection Ref.Type.Any
+@cindex Any type
+@cindex Dynamic type, see @i{Any type}
+@cindex Reflection
+@cindex Alt type statement
 
 The type @code{any} is the union of all possible Rust types. A value of type
 @code{any} is represented in memory as a pair consisting of a boxed value of
@@ -1784,6 +1888,10 @@ type extraction. @xref{Ref.Stmt.Alt}.
 
 @node       Ref.Type.Mach
 @subsection Ref.Type.Mach
+@cindex Machine types
+@cindex Floating-point types
+@cindex Integer types
+@cindex Word types
 
 The machine types are the following:
 
@@ -1825,12 +1933,15 @@ The signed two's complement word types @code{i8}, @code{i16}, @code{i32} and
 @end ifhtml
  respectively.
 @item
-The IEEE 754 single-precision and double-precision floating point types:
+The IEEE 754 single-precision and double-precision floating-point types:
 @code{f32} and @code{f64}, respectively.
 @end itemize
 
 @node       Ref.Type.Int
 @subsection Ref.Type.Int
+@cindex Machine-dependent types
+@cindex Integer types
+@cindex Word types
 
 
 The Rust type @code{uint}@footnote{A Rust @code{uint} is analogous to a C99
@@ -1845,6 +1956,8 @@ rust type @code{uint} on the same target machine.
 
 @node       Ref.Type.Float
 @subsection Ref.Type.Float
+@cindex Machine-dependent types
+@cindex Floating-point types
 
 The Rust type @code{float} is a machine-specific type equal to one of the
 supported Rust floating-point machine types (@code{f32} or @code{f64}). It is
@@ -1853,13 +1966,18 @@ target machine, or if the target machine has no floating-point hardware
 support, the largest floating-point type supported by the software
 floating-point library used to support the other floating-point machine types.
 
-Note that due to the preference for hardware-supported floating point, the
+Note that due to the preference for hardware-supported floating-point, the
 type @code{float} may not be equal to the largest @emph{supported}
 floating-point type.
 
 
 @node       Ref.Type.Prim
 @subsection Ref.Type.Prim
+@cindex Primitive types
+@cindex Integer types
+@cindex Floating-point types
+@cindex Character type
+@cindex Boolean type
 
 The primitive types are the following:
 
@@ -1882,6 +2000,8 @@ The machine-dependent integer and floating-point types.
 
 @node       Ref.Type.Big
 @subsection Ref.Type.Big
+@cindex Integer types
+@cindex Big integer type
 
 The Rust type @code{big}@footnote{A Rust @code{big} is analogous to a Lisp
 bignum or a Python long integer.} is an arbitrary precision integer type that
@@ -1895,6 +2015,12 @@ should only exhaust its range due to memory exhaustion.
 
 @node       Ref.Type.Text
 @subsection Ref.Type.Text
+@cindex Text types
+@cindex String type
+@cindex Character type
+@cindex Unicode
+@cindex UCS-4
+@cindex UTF-8
 
 The types @code{char} and @code{str} hold textual data.
 
@@ -1906,6 +2032,8 @@ A value of type @code{str} is a Unicode string, represented as a vector of
 
 @node       Ref.Type.Rec
 @subsection Ref.Type.Rec
+@cindex Record types
+@cindex Structure types, see @i{Record types}
 
 The record type-constructor @code{rec} forms a new heterogeneous product of
 values.@footnote{The @code{rec} type-constructor is analogous to the
@@ -1923,6 +2051,7 @@ let int px = p.x;
 
 @node       Ref.Type.Tup
 @subsection Ref.Type.Tup
+@cindex Tuple types
 
 The tuple type-constructor @code{tup} forms a new heterogeneous product of
 values exactly as the @code{rec} type-constructor does, with the difference
@@ -1943,6 +2072,8 @@ check (p._1 == "world");
 
 @node       Ref.Type.Vec
 @subsection Ref.Type.Vec
+@cindex Vector types
+@cindex Array types, see @i{Vector types}
 
 The vector type-constructor @code{vec} represents a homogeneous array of
 values of a given type. A vector has a fixed size. If the member-type of a
@@ -1981,6 +2112,8 @@ vector is always bounds-checked.
 
 @node       Ref.Type.Tag
 @subsection Ref.Type.Tag
+@cindex Tag types
+@cindex Union types, see @i{Tag types}
 
 The @code{tag} type-constructor forms new heterogeneous disjoint union
 types.@footnote{The @code{tag} type is analogous to a @code{data} constructor
@@ -2019,6 +2152,7 @@ let list[int] a = cons(7, cons(13, nil));
 
 @node       Ref.Type.Fn
 @subsection Ref.Type.Fn
+@cindex Function types
 
 The function type-constructor @code{fn} forms new function types. A function
 type consists of a sequence of input slots, an optional set of input
@@ -2040,6 +2174,7 @@ x = bo(5,7);
 
 @node       Ref.Type.Iter
 @subsection Ref.Type.Iter
+@cindex Iterator types
 
 The iterator type-constructor @code{iter} forms new iterator types. An
 iterator type consists a sequence of input slots, an optional set of input
@@ -2062,6 +2197,8 @@ for each (int i = range(5,7)) @{
 
 @node       Ref.Type.Port
 @subsection Ref.Type.Port
+@cindex Port types
+@cindex Communication
 
 The port type-constructor @code{port} forms types that describe ports. A port
 is the @emph{receiving end} of a typed, asynchronous, simplex inter-task
@@ -2083,6 +2220,8 @@ v <- p;
 
 @node       Ref.Type.Chan
 @subsection Ref.Type.Chan
+@cindex Channel types
+@cindex Communication
 
 The channel type-constructor @code{chan} forms types that describe channels. A
 channel is the @emph{sending end} of a typed, asynchronous, simplex inter-task
@@ -2117,6 +2256,7 @@ c <| v;
 
 @node       Ref.Type.Task
 @subsection Ref.Type.Task
+@cindex Task type
 
 The task type @code{task} describes values that are @emph{live
 tasks}.
@@ -2138,6 +2278,7 @@ holding those references), the released task immediately fails.
 @node       Ref.Type.Obj
 @subsection Ref.Type.Obj
 @c * Ref.Type.Obj::                Object types.
+@cindex Object types
 
 A @dfn{object type} describes values of abstract type, that carry some hidden
 @emph{fields} and are accessed through a set of un-ordered
@@ -2203,6 +2344,7 @@ give_ints(t2);
 @node       Ref.Type.Constr
 @subsection Ref.Type.Constr
 @c * Ref.Type.Constr::             Constrained types.
+@cindex Constrained types
 
 A @dfn{constrained type} is a type that carries a @emph{formal constraint}
 (@pxref{Ref.Stmt.Stat.Constr}), which is similar to a normal constraint except
@@ -2228,6 +2370,7 @@ let ordered_range rng2 = rec(low=15, high=17);
 @node       Ref.Type.Type
 @subsection Ref.Type.Type
 @c * Ref.Type.Type::               Types describing types.
+@cindex Type type
 
 @emph{TODO}.
 
@@ -2235,6 +2378,7 @@ let ordered_range rng2 = rec(low=15, high=17);
 @node    Ref.Expr
 @section Ref.Expr
 @c * Ref.Expr::               Parsed and primitive expressions.
+@cindex Expressions
 
 Rust has two kinds of expressions: @emph{parsed expressions} and
 @emph{primitive expressions}.  The former are syntactic sugar and are
@@ -2252,6 +2396,7 @@ right hand side of copy statements, @xref{Ref.Stmt.Copy}.
 @node    Ref.Stmt
 @section Ref.Stmt
 @c * Ref.Stmt::               Executable statements.
+@cindex Statements
 
 A @dfn{statement} is a component of a block, which is in turn a components of
 an outer block, a function or an iterator. When a function is spawned into a
@@ -2290,6 +2435,7 @@ actions.
 @node       Ref.Stmt.Stat
 @subsection Ref.Stmt.Stat
 @c * Ref.Stmt.Stat::         The static typestate system of statement analysis.
+@cindex Typestate system
 
 Statements have a detailed static semantics. The static semantics determine,
 on a statement-by-statement basis, the @emph{effects} the statement has on its
@@ -2303,7 +2449,7 @@ system.
 
 @menu
 * Ref.Stmt.Stat.Point::         Inter-statement positions of logical judgements.
-* Ref.Stmt.Stat.CFG::           The control flow graph formed by statements.
+* Ref.Stmt.Stat.CFG::           The control-flow graph formed by statements.
 * Ref.Stmt.Stat.Constr::        Predicates applied to slots.
 * Ref.Stmt.Stat.Cond::          Constraints required and implied by a statement.
 * Ref.Stmt.Stat.Typestate::     Constraints that hold at points.
@@ -2313,6 +2459,7 @@ system.
 @node          Ref.Stmt.Stat.Point
 @subsubsection Ref.Stmt.Stat.Point
 @c * Ref.Stmt.Stat.Point::         Inter-statement positions of logical judgements.
+@cindex Points
 
 A @dfn{point} exists before and after any statement in a Rust program.
 For example, this code:
@@ -2343,7 +2490,8 @@ memory.
 
 @node          Ref.Stmt.Stat.CFG
 @subsubsection Ref.Stmt.Stat.CFG
-@c * Ref.Stmt.Stat.CFG::           The control flow graph formed by statements.
+@c * Ref.Stmt.Stat.CFG::           The control-flow graph formed by statements.
+@cindex Control-flow graph
 
 Each @emph{point} can be considered a vertex in a directed @emph{graph}. Each
 kind of statement implies a single edge in this graph between the point before
@@ -2352,11 +2500,13 @@ from the points of the statement to points before other statements. The edges
 between points represent @emph{possible} indivisible control transfers that
 might occur during execution.
 
-This implicit graph is called the @dfn{control flow graph}, or @dfn{CFG}.
+This implicit graph is called the @dfn{control-flow graph}, or @dfn{CFG}.
 
 @node          Ref.Stmt.Stat.Constr
 @subsubsection Ref.Stmt.Stat.Constr
 @c * Ref.Stmt.Stat.Constr::          Predicates applied to slots.
+@cindex Predicate
+@cindex Constraint
 
 A @dfn{predicate} is any pure boolean function. @xref{Ref.Item.Fn}.
 
@@ -2387,6 +2537,9 @@ in those slots must be immutable.
 @node          Ref.Stmt.Stat.Cond
 @subsubsection Ref.Stmt.Stat.Cond
 @c * Ref.Stmt.Stat.Cond::          Constraints required and implied by a statement.
+@cindex Condition
+@cindex Precondition
+@cindex Postcondition
 
 A @dfn{condition} is a set of zero or more constraints.
 
@@ -2405,6 +2558,9 @@ postcondition is considered to be @emph{dropped} by the statement.
 @node          Ref.Stmt.Stat.Typestate
 @subsubsection Ref.Stmt.Stat.Typestate
 @c * Ref.Stmt.Stat.Typestate::     Constraints that hold at points.
+@cindex Typestate
+@cindex Prestate
+@cindex Poststate
 
 The typestate checking system @emph{calculates} an additional
 condition for each point called its typestate. For a given statement,
@@ -2453,6 +2609,8 @@ static (compile-time) error.
 @node          Ref.Stmt.Stat.Check
 @subsubsection Ref.Stmt.Stat.Check
 @c * Ref.Stmt.Stat.Check::         Relating dynamic state to static typestate.
+@cindex Check statement
+@cindex Assertions, see @i{Check statement}
 
 The key mechanism that connects run-time semantics and compile-time analysis
 of typestates is the use of @code{check} statements. @xref{Ref.Stmt.Check}. A
@@ -2484,6 +2642,7 @@ to hold in order to execute properly.
 @node       Ref.Stmt.Decl
 @subsection Ref.Stmt.Decl
 @c * Ref.Stmt.Decl::                Statement declaring an item or slot.
+@cindex Declaration statement
 
 A @dfn{declaration statement} is one that introduces a @emph{name} into the
 enclosing statement block. The declared name may denote a new slot or a new
@@ -2512,6 +2671,10 @@ declaring a function-local item.
 @node          Ref.Stmt.Decl.Slot
 @subsubsection Ref.Stmt.Decl.Slot
 @c * Ref.Stmt.Decl.Slot::                Statement declaring an slot.
+@cindex Local slot
+@cindex Variable, see @i{Local slot}
+@cindex Type inference
+@cindex Automatic slot
 
 A @code{slot declaration statement} has one one of two forms:
 
@@ -2540,6 +2703,8 @@ object signatures must always declared types for all argument slots.
 @node       Ref.Stmt.Copy
 @subsection Ref.Stmt.Copy
 @c * Ref.Stmt.Copy::                Statement for copying a value.
+@cindex Copy statement
+@cindex Assignment operator, see @i{Copy statement}
 
 A @dfn{copy statement} consists of an @emph{lval} followed by an equals-sign
 (@code{=}) and a primitive expression. @xref{Ref.Expr}.
@@ -2564,6 +2729,7 @@ x.y = z + 2;
 @node       Ref.Stmt.Spawn
 @subsection Ref.Stmt.Spawn
 @c * Ref.Stmt.Spawn::               Statements creating new tasks.
+@cindex Spawn statement
 
 A @code{spawn} statement consists of keyword @code{spawn}, followed by a
 normal @emph{call} statement (@pxref{Ref.Stmt.Call}).  A @code{spawn}
@@ -2594,6 +2760,8 @@ auto result <- out;
 @node       Ref.Stmt.Send
 @subsection Ref.Stmt.Send
 @c * Ref.Stmt.Send::            Statements for sending a value into a channel.
+@cindex Send statement
+@cindex Communication
 
 Sending a value through a channel can be done via two different statements.
 Both statements take an @emph{lval}, denoting a channel, and a value to send
@@ -2624,6 +2792,8 @@ c <| "hello, world";
 @node       Ref.Stmt.Flush
 @subsection Ref.Stmt.Flush
 @c * Ref.Stmt.Flush::              Statement for flushing a channel queue.
+@cindex Flush statement
+@cindex Communication
 
 A @code{flush} statement takes a channel and blocks the flushing task until
 the channel's queue has emptied. It can be used to implement a more precise
@@ -2640,6 +2810,8 @@ flush c;
 @node       Ref.Stmt.Recv
 @subsection Ref.Stmt.Recv
 @c * Ref.Stmt.Recv::           Statement for receiving a value from a channel.
+@cindex Receive statement
+@cindex Communication
 
 The @dfn{receive statement} takes an @var{lval} to receive into and an
 expression denoting a port, and applies the @emph{receive operator}
@@ -2659,6 +2831,8 @@ let str s <- p;
 @node       Ref.Stmt.Call
 @subsection Ref.Stmt.Call
 @c * Ref.Stmt.Call::               Statement for calling a function.
+@cindex Call statement
+@cindex Function calls
 
 A @dfn{call statement} invokes a function, providing a tuple of input slots
 and an alias slot to serve as the function's output, bound to the @var{lval}
@@ -2677,6 +2851,9 @@ let int x = add(1, 2);
 @node       Ref.Stmt.Bind
 @subsection Ref.Stmt.Bind
 @c * Ref.Stmt.Bind::          Statement for binding arguments to functions.
+@cindex Bind statement
+@cindex Closures
+@cindex Currying
 
 A @dfn{bind statement} constructs a new function from an existing
 function.@footnote{The @code{bind} statement is analogous to the @code{bind}
@@ -2722,6 +2899,7 @@ of them can be achieved with @code{bind} statements.
 @node       Ref.Stmt.Ret
 @subsection Ref.Stmt.Ret
 @c * Ref.Stmt.Ret::                Statement for stopping and producing a value.
+@cindex Return statement
 
 Executing a @code{ret} statement@footnote{A @code{ret} statement is analogous
 to a @code{return} statement in the C family.}  copies a value into the output
@@ -2741,6 +2919,8 @@ fn max(int a, int b) -> int @{
 @node       Ref.Stmt.Be
 @subsection Ref.Stmt.Be
 @c * Ref.Stmt.Be::                 Statement for stopping and executing a tail call.
+@cindex Be statement
+@cindex Tail calls
 
 Executing a @code{be} statement @footnote{A @code{be} statement in is
 analogous to a @code{become} statement in Newsqueak or Alef.}  destroys the
@@ -2770,6 +2950,8 @@ copy of itself.
 @node       Ref.Stmt.Put
 @subsection Ref.Stmt.Put
 @c * Ref.Stmt.Put::                Statement for pausing and producing a value.
+@cindex Put statement
+@cindex Iterators
 
 Executing a @code{put} statement copies a value into the output slot of the
 current iterator, suspends execution of the current iterator, and transfers
@@ -2789,6 +2971,9 @@ execution and destroying the iterator frame.
 @node       Ref.Stmt.Fail
 @subsection Ref.Stmt.Fail
 @c * Ref.Stmt.Fail::               Statement for causing task failure.
+@cindex Fail statement
+@cindex Failure
+@cindex Unwinding
 
 Executing a @code{fail} statement causes a task to enter the @emph{failing}
 state. In the @emph{failing} state, a task unwinds its stack, destroying all
@@ -2798,6 +2983,8 @@ point it halts execution in the @emph{dead} state.
 @node       Ref.Stmt.Log
 @subsection Ref.Stmt.Log
 @c * Ref.Stmt.Log::                Statement for logging values to diagnostic buffers.
+@cindex Log statement
+@cindex Logging
 
 Executing a @code{log} statement may, depending on runtime configuration,
 cause a value to be appended to an internal diagnostic logging buffer provided
@@ -2815,6 +3002,10 @@ contains a log statement.
 @node       Ref.Stmt.Note
 @subsection Ref.Stmt.Note
 @c * Ref.Stmt.Note::                Statement for logging values during failure.
+@cindex Note statement
+@cindex Logging
+@cindex Unwinding
+@cindex Failure
 
 A @code{note} statement has no effect during normal execution. The purpose of
 a @code{note} statement is to provide additional diagnostic information to the
@@ -2858,6 +3049,9 @@ logged during unwinding, @emph{not} the original value that was denoted by the
 @node       Ref.Stmt.While
 @subsection Ref.Stmt.While
 @c * Ref.Stmt.While::              Statement for simple conditional looping.
+@cindex While statement
+@cindex Loops
+@cindex Control-flow
 
 A @code{while} statement is a loop construct. A @code{while} loop may be
 either a simple @code{while} or a @code{do}-@code{while} loop.
@@ -2892,6 +3086,9 @@ do @{
 @node       Ref.Stmt.Break
 @subsection Ref.Stmt.Break
 @c * Ref.Stmt.Break::              Statement for terminating a loop.
+@cindex Break statement
+@cindex Loops
+@cindex Control-flow
 
 Executing a @code{break} statement immediately terminates the innermost loop
 enclosing it. It is only permitted in the body of a loop.
@@ -2899,6 +3096,9 @@ enclosing it. It is only permitted in the body of a loop.
 @node       Ref.Stmt.Cont
 @subsection Ref.Stmt.Cont
 @c * Ref.Stmt.Cont::               Statement for terminating a single loop iteration.
+@cindex Continue statement
+@cindex Loops
+@cindex Control-flow
 
 Executing a @code{cont} statement immediately terminates the current iteration
 of the innermost loop enclosing it, returning control to the loop
@@ -2913,6 +3113,9 @@ A @code{cont} statement is only permitted in the body of a loop.
 @node       Ref.Stmt.For
 @subsection Ref.Stmt.For
 @c * Ref.Stmt.For::                Statement for looping over strings and vectors.
+@cindex For statement
+@cindex Loops
+@cindex Control-flow
 
 A @dfn{for loop} is controlled by a vector or string. The for loop
 bounds-checks the underlying sequence @emph{once} when initiating the loop,
@@ -2945,6 +3148,9 @@ for (&foo e in v) @{
 @node          Ref.Stmt.Foreach
 @subsection    Ref.Stmt.Foreach
 @c * Ref.Stmt.Foreach::           Statement for general conditional looping.
+@cindex Foreach statement
+@cindex Loops
+@cindex Control-flow
 
 An @dfn{foreach loop} is denoted by the @code{for each} keywords, and is
 controlled by an iterator. The loop executes once for each value @code{put} by
@@ -2963,6 +3169,8 @@ for each (&str s = _str.split(txt, "\n")) @{
 @node       Ref.Stmt.If
 @subsection Ref.Stmt.If
 @c * Ref.Stmt.If::                 Statement for simple conditional branching.
+@cindex If statement
+@cindex Control-flow
 
 An @code{if} statement is a conditional branch in program control. The form of
 an @code{if} statement is a parenthesized condition expression, followed by a
@@ -2975,6 +3183,9 @@ block is skipped and any @code{else} block is executed.
 @node       Ref.Stmt.Alt
 @subsection Ref.Stmt.Alt
 @c * Ref.Stmt.Alt::                Statement for complex conditional branching.
+@cindex Alt statement
+@cindex Control-flow
+@cindex Switch statement, see @i{Alt statement}
 
 An @code{alt} statement is a multi-directional branch in program control.
 There are three kinds of @code{alt} statement: communication @code{alt}
@@ -2997,6 +3208,10 @@ statement following the @code{alt} when the case block completes.
 @node          Ref.Stmt.Alt.Comm
 @subsubsection Ref.Stmt.Alt.Comm
 @c * Ref.Stmt.Alt.Comm::           Statement for branching on communication events.
+@cindex Communication alt statement
+@cindex Control-flow
+@cindex Communication
+@cindex Multiplexing
 
 The simplest form of @code{alt} statement is the a @emph{communication}
 @code{alt}. The cases of a communication @code{alt}'s arms are send, receive
@@ -3030,6 +3245,8 @@ alt @{
 @node          Ref.Stmt.Alt.Pat
 @subsubsection Ref.Stmt.Alt.Pat
 @c * Ref.Stmt.Alt.Pat::            Statement for branching on pattern matches.
+@cindex Pattern alt statement
+@cindex Control-flow
 
 A pattern @code{alt} statement branches on a @emph{pattern}. The exact form of
 matching that occurs depends on the pattern. Patterns consist of some
@@ -3069,6 +3286,8 @@ alt (x) @{
 @node          Ref.Stmt.Alt.Type
 @subsubsection Ref.Stmt.Alt.Type
 @c * Ref.Stmt.Alt.Type::           Statement for branching on type.
+@cindex Type alt statement
+@cindex Control-flow
 
 An @code{alt type} statement is similar to a pattern @code{alt}, but branches
 on the @emph{type} of its head expression, rather than the value. The head
@@ -3102,6 +3321,8 @@ alt type (x) @{
 @node       Ref.Stmt.Prove
 @subsection Ref.Stmt.Prove
 @c * Ref.Stmt.Prove::              Statement for static assertion of typestate.
+@cindex Prove statement
+@cindex Typestate system
 
 A @code{prove} statement has no run-time effect. Its purpose is to statically
 check (and document) that its argument constraint holds at its statement entry
@@ -3111,6 +3332,8 @@ the program containing it will fail to compile.
 @node       Ref.Stmt.Check
 @subsection Ref.Stmt.Check
 @c * Ref.Stmt.Check::              Statement for dynamic assertion of typestate.
+@cindex Check statement
+@cindex Typestate system
 
 A @code{check} statement connects dynamic assertions made at run-time to the
 static typestate system. A @code{check} statement takes a constraint to check
@@ -3152,10 +3375,13 @@ fn test() @{
 @node       Ref.Stmt.IfCheck
 @subsection Ref.Stmt.IfCheck
 @c * Ref.Stmt.IfCheck::            Statement for dynamic testing of typestate.
+@cindex If check statement
+@cindex Typestate system
+@cindex Control-flow
 
 An @code{if check} statement combines a @code{if} statement and a @code{check}
 statement in an indivisible unit that can be used to build more complex
-conditional control flow than the @code{check} statement affords.
+conditional control-flow than the @code{check} statement affords.
 
 In fact, @code{if check} is a ``more primitive'' statement @code{check};
 instances of the latter can be rewritten as instances of the former. The
@@ -3182,6 +3408,7 @@ if check even(x) @{
 @node    Ref.Run
 @section Ref.Run
 @c * Ref.Run::                     Organization of runtime services.
+@cindex Runtime library
 
 The Rust @dfn{runtime} is a relatively compact collection of C and Rust code
 that provides fundamental services and datatypes to all Rust tasks at
@@ -3201,6 +3428,7 @@ communication, reflection, logging and signal handling.
 @node       Ref.Run.Mem
 @subsection Ref.Run.Mem
 @c * Ref.Run.Mem::                 Runtime memory management service.
+@cindex Memory allocation
 
 The runtime memory-management system is based on a @emph{service-provider
 interface}, through which the runtime requests blocks of memory from its
@@ -3215,6 +3443,7 @@ allocating and freeing boxed values.
 @node       Ref.Run.Type
 @subsection Ref.Run.Type
 @c * Ref.Run.Mem::                 Runtime built-in type services.
+@cindex Built-in types
 
 The runtime provides C and Rust code to manage several built-in types:
 @itemize
@@ -3231,6 +3460,9 @@ records, and tags is open-coded by the Rust compiler.
 @node       Ref.Run.Comm
 @subsection Ref.Run.Comm
 @c * Ref.Run.Comm::                Runtime communication service.
+@cindex Communication
+@cindex Process
+@cindex Thread
 
 The runtime provides code to manage inter-task communication.  This includes
 the system of task-lifecycle state transitions depending on the contents of
@@ -3241,6 +3473,8 @@ communication facilities.
 @node       Ref.Run.Refl
 @subsection Ref.Run.Refl
 @c * Ref.Run.Refl::                Runtime reflection system.
+@cindex Reflection
+@cindex DWARF
 
 The runtime reflection system is driven by the DWARF tables emitted into a
 crate at compile-time. Reflecting on a slot or item allocates a Rust data
@@ -3249,6 +3483,7 @@ structure corresponding to the DWARF DIE for that slot or item.
 @node       Ref.Run.Log
 @subsection Ref.Run.Log
 @c * Ref.Run.Log::                 Runtime logging system.
+@cindex Logging
 
 The runtime contains a system for directing logging statements to a logging
 console and/or internal logging buffers. @xref{Ref.Stmt.Log}.  Logging
@@ -3279,6 +3514,7 @@ need to filter logs based on these two built-in dimensions.
 @node       Ref.Run.Sig
 @subsection Ref.Run.Sig
 @c * Ref.Run.Sig::               Runtime signal handler.
+@cindex Signals
 
 The runtime signal-handling system is driven by a signal-dispatch table and a
 signal queue associated with each task. Sending a signal to a task inserts the