Fix typo and Carl Hewitt's name

[mudman.git] / md / language.md

diff --git a/md/language.md b/md/language.md
index 5649126c82c8ac65521f49427424306b42bdf31e..fa5b46940dfad634bc5fe342c77b5a295ce44818 100644 (file)
--- a/md/language.md
+++ b/md/language.md
@@ -60,7 +60,7 @@ Acknowledgements
 
 I was not a member of the original group which labored for two years
 in the design and initial implementation of Muddle; that group was
 
 I was not a member of the original group which labored for two years
 in the design and initial implementation of Muddle; that group was

-composed principally of Gerald Sussman, Carl Hewit, Chris Reeve, Dave
+composed principally of Gerald Sussman, Carl Hewitt, Chris Reeve, Dave

 Cressey, and later Bruce Daniels. I would therefore like to take this
 opportunity to thank my Muddle mentors, chiefly Chris Reeve and Bruce
 Daniels, for remaining civil through several months of verbal
 Cressey, and later Bruce Daniels. I would therefore like to take this
 opportunity to thank my Muddle mentors, chiefly Chris Reeve and Bruce
 Daniels, for remaining civil through several months of verbal


@@ -156,7 +156,7 @@ a computer terminal appears herein in a fixed width font, as in
 `ROOT`. A metasyntactic variable -- something to be replaced in actual
 use by something else -- appears as *radix:fix*, in an italic font;
 often the variable will have both a meaning and a data type (as here),
 `ROOT`. A metasyntactic variable -- something to be replaced in actual
 use by something else -- appears as *radix:fix*, in an italic font;
 often the variable will have both a meaning and a data type (as here),

-but sometimes one of those will be ommitted, for obvious reasons.
+but sometimes one of those will be omitted, for obvious reasons.

 
 An ellipsis (...) indicates that something uninteresting has been
 omitted. The character `^` means that the following character is to be
 
 An ellipsis (...) indicates that something uninteresting has been
 omitted. The character `^` means that the following character is to be


@@ -209,7 +209,7 @@ interpreted as an expression(s) in Muddle. When this interpretation is
 done, the result will be printed and Muddle will wait for more typing.
 `ESC` will be represented by the glyph `$` in this document.
 
 done, the result will be printed and Muddle will wait for more typing.
 `ESC` will be represented by the glyph `$` in this document.
 

-Typing the rubout character (`DEL` in the ITS and Top-20 versions,
+Typing the rubout character (`DEL` in the ITS and Tops-20 versions,

 `CTRL`+`A` in the Tenex version) causes the last character in the
 buffer -- the one most recently typed -- to be thrown away (deleted).
 If you now immediately type another rubout, once again the last
 `CTRL`+`A` in the Tenex version) causes the last character in the
 buffer -- the one most recently typed -- to be thrown away (deleted).
 If you now immediately type another rubout, once again the last


@@ -2008,7 +2008,7 @@ cases, since Direct Representation usually produces exactly the same
 effect (in the absence of errors), and the intention is more apparent.
 \[Note: if `.L` is a `LIST`, `<LIST !.L>` makes a copy of `.L` whereas
 `(!.L)` doesn't; see section 7.7.\] `STRING`, on the other hand,
 effect (in the absence of errors), and the intention is more apparent.
 \[Note: if `.L` is a `LIST`, `<LIST !.L>` makes a copy of `.L` whereas
 `(!.L)` doesn't; see section 7.7.\] `STRING`, on the other hand,

-produces effect very different from literal `STRING`s.
+produces effects very different from literal `STRING`s.

 
 Examples:
 
 
 Examples:
 


@@ -4705,7 +4705,7 @@ Muddle behaves like the ITS version of the text editor Teco with
 respect to typing in carriage-return, in that it automatically adds a
 line-feed. In order to type in a lone carriage-return, a
 carriage-return followed by a rubout must be typed. Also `PRINT`,
 respect to typing in carriage-return, in that it automatically adds a
 line-feed. In order to type in a lone carriage-return, a
 carriage-return followed by a rubout must be typed. Also `PRINT`,

-`PRINT1` and `PRINC` do not automatically add a line-feed when a
+`PRIN1` and `PRINC` do not automatically add a line-feed when a

 carriage-return is output. This enables overstriking on a terminal
 that lacks backspacing capability. It also means that what goes on a
 terminal and what goes in a file are more likely to look the same.
 carriage-return is output. This enables overstriking on a terminal
 that lacks backspacing capability. It also means that what goes on a
 terminal and what goes in a file are more likely to look the same.


@@ -7130,7 +7130,7 @@ is written, so that the code is not duplicated on disk. A purified
 produces objects of `TYPE` `LOCR` instead of `LOCD`.
 
 19.5. TYPE-C and TYPE-W
 produces objects of `TYPE` `LOCR` instead of `LOCD`.
 
 19.5. TYPE-C and TYPE-W

-=======================
+-----------------------

 
 In order to handle user `NEWTYPE`s reasonably, the internal `TYPE`
 codes for them have to be able to be different from one Muddle run to
 
 In order to handle user `NEWTYPE`s reasonably, the internal `TYPE`
 codes for them have to be able to be different from one Muddle run to


@@ -7907,7 +7907,7 @@ At any given time there is a defined **interrupt level**. This is a
 `FIX` which determines which interrupts can really "interrupt" -- that
 is, cause the current processing to be suspended while their wants are
 satisfied. Normal, non-interrupt programs operate at an interrupt
 `FIX` which determines which interrupts can really "interrupt" -- that
 is, cause the current processing to be suspended while their wants are
 satisfied. Normal, non-interrupt programs operate at an interrupt

-level of 0 (zero.) An interrupt is processed at an interrupt level
+level of 0 (zero). An interrupt is processed at an interrupt level

 equal to the interrupt's priority.
 
 ### 21.7.1. Interrupt Processing
 equal to the interrupt's priority.
 
 ### 21.7.1. Interrupt Processing


@@ -7957,13 +7957,13 @@ If `INT-LEVEL` lowers the priority of the interrupt level, it does not
 priority than the target priority have been processed.
 
 Setting the `INT-LEVEL` extremely high (for example,
 priority than the target priority have been processed.
 
 Setting the `INT-LEVEL` extremely high (for example,

-`<INT-LEVEL <CHTPE <MIN> FIX>>`) effectively disables all interrupts
+`<INT-LEVEL <CHTYPE <MIN> FIX>>`) effectively disables all interrupts

 (but occurrences of enabled interrupts will still be queued).
 
 If `LISTEN` or `ERROR` is called when the `INT-LEVEL` is not zero,
 then the typeout will be
 
 (but occurrences of enabled interrupts will still be queued).
 
 If `LISTEN` or `ERROR` is called when the `INT-LEVEL` is not zero,
 then the typeout will be
 

-    LISTENING-AT-LEVEL I PROCESS p INT-LEVEL i
+    LISTENING-AT-LEVEL l PROCESS p INT-LEVEL i

 
 ### 21.7.3. DISMISS
 
 
 ### 21.7.3. DISMISS
 


@@ -7994,7 +7994,7 @@ Muddle is communicating with a person or another processor. Each
 interrupt, and the mode of the `CHANNEL` tells what kinds of `"CHAR"`
 interrupts occur to be handled through that `IHEADER`.
 
 interrupt, and the mode of the `CHANNEL` tells what kinds of `"CHAR"`
 interrupts occur to be handled through that `IHEADER`.
 

-1.  If the `CHANNEL` is for `INPUT`, "CHAR" occurs every time an
+1.  If the `CHANNEL` is for `INPUT`, `"CHAR"` occurs every time an

     "interesting" character (see below) is received from the
     `CHANNEL`'s real terminal, or any character is received from the
     `CHANNEL`'s pseudo-terminal, or a character or word is received
     "interesting" character (see below) is received from the
     `CHANNEL`'s real terminal, or any character is received from the
     `CHANNEL`'s pseudo-terminal, or a character or word is received


@@ -8017,7 +8017,7 @@ which it was typed.
 In the ITS version, the "interesting" characters are those "enabled
 for interrupts" on a real terminal, namely `^@` through `^G`, `^K`
 through `^_`, and `DEL` (that is, ASCII codes 0-7, 13-37, and 177
 In the ITS version, the "interesting" characters are those "enabled
 for interrupts" on a real terminal, namely `^@` through `^G`, `^K`
 through `^_`, and `DEL` (that is, ASCII codes 0-7, 13-37, and 177

-octal.)
+octal).

 
 In the Tenex and Tops-20 versions, the operating system can be told
 which characters typed on a terminal should cause this interrupt to
 
 In the Tenex and Tops-20 versions, the operating system can be told
 which characters typed on a terminal should cause this interrupt to


@@ -8065,7 +8065,7 @@ an input `CHANNEL` open to a pseudo-terminal ("STY" device and
 friends). An interrupt occurs when a character is available for input.
 These interrupts are set up in exactly the same way as real-terminal
 interrupts, except that a handler gets applied to only **one**
 friends). An interrupt occurs when a character is available for input.
 These interrupts are set up in exactly the same way as real-terminal
 interrupts, except that a handler gets applied to only **one**

-argument, the `CHANNEL`. Pseudo-terminal are not available in the
+argument, the `CHANNEL`. Pseudo-terminals are not available in the

 Tenex and Tops-20 versions.
 
 For any other flavor of ITS channel interrupt, a handler gets applied
 Tenex and Tops-20 versions.
 
 For any other flavor of ITS channel interrupt, a handler gets applied


@@ -8131,7 +8131,7 @@ unfortunately).
 a deferrable garbage collection that is needed because of exhausted
 movable garbage-collected storage. Enabling this interrupt is the only
 way a program can know that a garbage collection is about to occur. A
 a deferrable garbage collection that is needed because of exhausted
 movable garbage-collected storage. Enabling this interrupt is the only
 way a program can know that a garbage collection is about to occur. A

-handler takes two arguments: A `FIX` telling the number of machine
+handler takes two arguments: a `FIX` telling the number of machine

 words needed and an `ATOM` telling what initiated the garbage
 collection (see above). If it wishes, a handler can try to prevent a
 garbage collection by calling `BLOAT` with the `FIX` argument. If the
 words needed and an `ATOM` telling what initiated the garbage
 collection (see above). If it wishes, a handler can try to prevent a
 garbage collection by calling `BLOAT` with the `FIX` argument. If the


@@ -8143,7 +8143,7 @@ try to cause a garbage collection.
 ### 21.8.6. "CLOCK"
 
 `"CLOCK"`, when enabled, occurs every half second (the ITS
 ### 21.8.6. "CLOCK"
 
 `"CLOCK"`, when enabled, occurs every half second (the ITS

-"slow-clock" tick.) It is not available in the Tenex or Tops-20
+"slow-clock" tick). It is not available in the Tenex or Tops-20

 versions. It wants handlers which take no arguments. Example:
 
     <ON "CLOCK" <FUNCTION () <PRINC "TICK ">> 1>
 versions. It wants handlers which take no arguments. Example:
 
     <ON "CLOCK" <FUNCTION () <PRINC "TICK ">> 1>


@@ -8166,9 +8166,9 @@ character.
 ### 21.8.8. "UNBLOCKED"
 
 `"UNBLOCKED"` occurs whenever a `$` (`ESC`) is typed on a terminal if
 ### 21.8.8. "UNBLOCKED"
 
 `"UNBLOCKED"` occurs whenever a `$` (`ESC`) is typed on a terminal if

-a program was hanging and waiting for input, or when a TYI call (which
-see) is satisfied. A handler takes one argument: the `CHANNEL` via
-which the `$` or character is input.
+a program was hanging and waiting for input, or when a `TYI` call
+(which see) is satisfied. A handler takes one argument: the `CHANNEL`
+via which the `$` or character is input.

 
 ### 21.8.9. "READ" and "WRITE"
 
 
 ### 21.8.9. "READ" and "WRITE"
 


@@ -8250,7 +8250,7 @@ process. It is not available in the Tenex and Tops-20 versions. A
 handler takes one argument: A `FIX` between `0` and `7` inclusive,
 telling which inferior process is interrupting.
 
 handler takes one argument: A `FIX` between `0` and `7` inclusive,
 telling which inferior process is interrupting.
 

-### 21.8.14. "RUNT and "REALT"
+### 21.8.14. "RUNT" and "REALT"

 
 These are not available in the Tenex and Tops-20 versions.
 
 
 These are not available in the Tenex and Tops-20 versions.
 


@@ -8274,7 +8274,7 @@ argument, or `#FALSE ()` if `REALTIMER` has not been called.
 `"MPV"` ("memory protection violation") occurs if Muddle tries to
 refer to a storage address not in its address space. `"PURE"` occurs
 if Muddle tries to alter read-only storage. `"ILOPR"` occurs if Muddle
 `"MPV"` ("memory protection violation") occurs if Muddle tries to
 refer to a storage address not in its address space. `"PURE"` occurs
 if Muddle tries to alter read-only storage. `"ILOPR"` occurs if Muddle

-executes and illegal instruction ("operator"). `"PARITY"` occurs if
+executes an illegal instruction ("operator"). `"PARITY"` occurs if

 the CPU detects a parity error in Muddle's address space. All of these
 require a handler that takes one argument: the address (`TYPE` `WORD`)
 following the instruction that was being executed at the time.
 the CPU detects a parity error in Muddle's address space. All of these
 require a handler that takes one argument: the address (`TYPE` `WORD`)
 following the instruction that was being executed at the time.


@@ -8292,7 +8292,7 @@ system process instead of to Muddle. In the ITS version, if and when a
     interrupt goes to the superior operating system process.
 -   If an `IHEADER` is associated but disabled, the error
     `DANGEROUS-INTERRUPT-NOT-HANDLED` occurs (`FILE-SYSTEM-ERROR` for
     interrupt goes to the superior operating system process.
 -   If an `IHEADER` is associated but disabled, the error
     `DANGEROUS-INTERRUPT-NOT-HANDLED` occurs (`FILE-SYSTEM-ERROR` for

-    \`"IOC").
+    `"IOC"`).

 -   If an `IHEADER` is associated and enabled, but the `INT-LEVEL` is
     too high, the error `ATTEMPT-TO-DEFER-UNDEFERABLE-INTERRUPT`
     occurs.
 -   If an `IHEADER` is associated and enabled, but the `INT-LEVEL` is
     too high, the error `ATTEMPT-TO-DEFER-UNDEFERABLE-INTERRUPT`
     occurs.


@@ -8399,9 +8399,9 @@ when space becomes full varies, as discussed below.
 
 Most storage used explicitly by Muddle programs is obtained from a
 pool of free storage managed by a "garbage collector". Storage is
 
 Most storage used explicitly by Muddle programs is obtained from a
 pool of free storage managed by a "garbage collector". Storage is

-obtained from this pool by the `SUBR`s which construct objects. When a
-`SUBR` finds that the pool of available storage is exhausted, it
-automatically calls the garbage collector.
+obtained from this pool by the `SUBR`s which construct objects. When
+such a `SUBR` finds that the pool of available storage is exhausted,
+it automatically calls the garbage collector.

 
 The garbage collector has two algorithms available to it: the
 "copying" algorithm, which is used by default, and the "mark-sweep"
 
 The garbage collector has two algorithms available to it: the
 "copying" algorithm, which is used by default, and the "mark-sweep"


@@ -8430,7 +8430,7 @@ Only when the total system resources are exhausted will you finally
 lose.
 
 Thus, if you just "forget about" an object, that is, lose all possible
 lose.
 
 Thus, if you just "forget about" an object, that is, lose all possible

-means of referencing it, its storage is automatically reclaimed.
+means of referencing it, its storage area is automatically reclaimed.

 "Object" in this context includes that stack-structured storage space
 used in `PROCESS`es for functional application.
 
 "Object" in this context includes that stack-structured storage space
 used in `PROCESS`es for functional application.
 


@@ -8555,8 +8555,9 @@ becomes full, Muddle goes through the following procedure:
 5.  Finally, the "mark-sweep" algorithm sweeps through the storage
     space, adding unmarked objects to the internal free lists for
     later re-use. The "copying" algorithm maps the inferior process's
 5.  Finally, the "mark-sweep" algorithm sweeps through the storage
     space, adding unmarked objects to the internal free lists for
     later re-use. The "copying" algorithm maps the inferior process's

-    address space into Muddle's own, replacing old garbagey with the
-    new compact storage, and the inferior process is destroyed.
+    address space into Muddle's own, replacing old garbagey storage
+    with the new compact storage, and the inferior process is
+    destroyed.

 
 22.5 GC
 -------
 
 22.5 GC
 -------


@@ -8565,24 +8566,44 @@ becomes full, Muddle goes through the following procedure:
 
 causes the garbage collector to run and returns the total number of
 words of storage reclaimed. All of its arguments are optional: if they
 
 causes the garbage collector to run and returns the total number of
 words of storage reclaimed. All of its arguments are optional: if they

-are not supplied, a call to GC simply causes a "copying" garbage
+are not supplied, a call to `GC` simply causes a "copying" garbage

 collection.
 
 If *min* is explicitly supplied as an argument, a garbage-collection
 parameter is changed permanently before the garbage collector runs.
 *min* is the smallest number of words of "free" (unclaimed, available
 for use) movable garbage-collected storage the garbage collector will
 collection.
 
 If *min* is explicitly supplied as an argument, a garbage-collection
 parameter is changed permanently before the garbage collector runs.
 *min* is the smallest number of words of "free" (unclaimed, available
 for use) movable garbage-collected storage the garbage collector will

-be satisfied with having after it is done. Initially it is 8192 words.
-If the total amount of reclaimed storage is less than *min*, the
-garbage collector will ask the operating system for enough storage (in
-1024 word blocks) to make it up. N.B.: the system may be incivil
-enough not to grant the request; in that case, the garbage collector
-will be content with what it has, **unless** that is not enough to
-satisfy a **pending** request for storage. Then it will inform you
-that it is losing. A large *min* will result in fewer total garbage
-collections, but they will take longer since the total quantity of
-storage to be dealt with will generally be larger. Smaller *min*s
-result in shorter, more frequent garbage collections.
+be satisfied with having after it is done each time. Initially it is
+8192 words.  If the total amount of reclaimed storage is less than
+*min*, the garbage collector will ask the operating system for enough
+storage (in 1024-word blocks) to make it up. N.B.: the system may be
+incivil enough not to grant the request; in that case, the garbage
+collector will be content with what it has, **unless** that is not
+enough to satisfy a **pending** request for storage. Then it will
+inform you that it is losing. A large *min* will result in fewer total
+garbage collections, but they will take longer since the total
+quantity of storage to be dealt with will generally be larger. Smaller
+*min*s result in shorter, more frequent garbage collections.
+
+*exh?* tells whether or not this garbage collection should be
+"exhaustive". It is optional, a `FALSE` by default. The difference
+between normal and exhaustive "copying" garbage collections is whether
+certain kinds of storage that require complicated treatment (for
+example, associations) are reclaimed. An exhaustive garbage collection
+occurs every eighth time that the "copying" algorithm is used, or when
+`GC` is called with this argument true, or when a normal garbage
+collection cannot satisfy the storage request.
+
+*ms-freq* gives the number of times the "mark-sweep" algorithm should
+be used hereafter for every time the normal "copying" algorithm is
+used. Giving `0` for *ms-freq* means never to use the "mark-sweep"
+algorithm, and giving `<CHTYPE <MIN> FIX>` means (effectively) always
+to use it. The "mark-sweep" algorithm uses considerably less processor
+time than the "copying" algorithm, but it never shrinks the
+free-storage pool, and in fact the pool can become fragmented. The
+"mark-sweep" algorithm could be useful in a program system (such as
+the compiler) where the size of the pool rarely changes, but objects
+are created and thrown away continuously.

 
 22.6. BLOAT
 -----------
 
 22.6. BLOAT
 -----------


@@ -8623,8 +8644,8 @@ by default), and indicate the following:
     `READ`ing large `STRING`s, and calling routines within the
     interpreter and compiled programs)
 
     `READ`ing large `STRING`s, and calling routines within the
     interpreter and compiled programs)
 

-Arguments on the second line are also `FIX` and optional, but they set
-garbage-collection parameters permanently, as follows:
+Arguments on the second line above are also `FIX` and optional, but
+they set garbage-collection parameters permanently, as follows:

 
 -   *min*: as for `GC`
 -   *plcl*: number of slots for `LVAL`s added when the space for
 
 -   *min*: as for `GC`
 -   *plcl*: number of slots for `LVAL`s added when the space for


@@ -8693,7 +8714,7 @@ about certain areas of storage. In detail:
 22.8. GC-MON
 ------------
 
 22.8. GC-MON
 ------------
 

-    <GC-MOND pred>
+    <GC-MON pred>

 
 ("garbage-collector monitor") determines whether or not the
 interpreter will hereafter print information on the terminal when a
 
 ("garbage-collector monitor") determines whether or not the
 interpreter will hereafter print information on the terminal when a


@@ -8719,7 +8740,7 @@ of `GIN` and `GOUT`.
 Two `SUBR`s, described next, use only part of the garbage-collector
 algorithm, in order to find all pointers to an object. `GC-DUMP` and
 `GC-READ`, as their names imply, also use part in order to translate
 Two `SUBR`s, described next, use only part of the garbage-collector
 algorithm, in order to find all pointers to an object. `GC-DUMP` and
 `GC-READ`, as their names imply, also use part in order to translate

-between Muddle objects and binary representation thereof.
+between Muddle objects and binary representations thereof.

 
 ### 22.9.1. SUBSTITUTE
 
 
 ### 22.9.1. SUBSTITUTE
 


@@ -8734,7 +8755,7 @@ the few legitimate uses for it is to substitute the "right" `ATOM` for
 the "wrong" one, after `OBLIST`s have been in the wrong state. This is
 more or less the way `ATOM`s are impurified. It is also useful for
 unlinking `RSUBR`s. `SUBSTITUTE` returns *old* as a favor: unless you
 the "wrong" one, after `OBLIST`s have been in the wrong state. This is
 more or less the way `ATOM`s are impurified. It is also useful for
 unlinking `RSUBR`s. `SUBSTITUTE` returns *old* as a favor: unless you

-hang onto *old* at that point, it will be garbage-collected.
+hang onto *old* at that point, it will be garbage.

 
 22.9.2 PURIFY
 -------------
 
 22.9.2 PURIFY
 -------------


@@ -8815,10 +8836,10 @@ control passes to the superior process.
 ("value return") seldom returns. It passes control back up the process
 tree to the superior of Muddle, passing its argument as a message to
 that superior. If it does return, the value is `#FALSE ()`. If the
 ("value return") seldom returns. It passes control back up the process
 tree to the superior of Muddle, passing its argument as a message to
 that superior. If it does return, the value is `#FALSE ()`. If the

-argument is a `STRING`, it is passed to the superior as a command to
+argument is a `STRING`, it is passed to the superior as commands to

 be executed, via `.VALUE` in the ITS version and `RSCAN` in the
 Tops-20 version. If the argument is a `FIX`, it is passed to the
 be executed, via `.VALUE` in the ITS version and `RSCAN` in the
 Tops-20 version. If the argument is a `FIX`, it is passed to the

-superior as the "effective address" of a `.BREAK 16`, instruction in
+superior as the "effective address" of a `.BREAK 16,` instruction in

 the ITS version and ignored in other versions.
 
 23.4. Inter-process Communication
 the ITS version and ignored in other versions.
 
 23.4. Inter-process Communication