diff --git a/README.md b/README.md
index 364cfe3..430ce62 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,7 @@ LISP 1.5 is to all Lisp dialects as Beowulf is to English literature.
A work-in-progress towards an implementation of Lisp 1.5 in Clojure. The
objective is to build a complete and accurate implementation of Lisp 1.5
as described in the manual, with, in so far as is possible, exactly the
-same bahaviour - except as documented below.
+same behaviour — except as documented below.
### BUT WHY?!!?!
@@ -62,14 +62,11 @@ Working Lisp interpreter, but some key features not yet implemented.
### Project Target
-The project target is to be able to run the [Wang algorithm for the propositional calculus](https://www.softwarepreservation.org/projects/LISP/book/LISP%201.5%20Programmers%20Manual.pdf#page=52) given in chapter 8 of the *Lisp 1.5 Programmer's Manual*. When that runs, the project is as far as I am concerned feature complete. I may keep tinkering with it after that and I'll certainly accept pull requests which are in the spirit of the project (i.e. making Beowulf more usable, and/or implementing parts of Lisp 1.5 which I have not implemented), but this isn't intended to be a new language for doing real work; it's an
-educational and archaeological project, not serious engineering.
+The project target is to be able to run the [Wang algorithm for the propositional calculus](https://www.softwarepreservation.org/projects/LISP/book/LISP%201.5%20Programmers%20Manual.pdf#page=52) given in chapter 8 of the *Lisp 1.5 Programmer's Manual*. When that runs, the project is as far as I am concerned feature complete. I may keep tinkering with it after that and I'll certainly accept pull requests which are in the spirit of the project (i.e. making Beowulf more usable, and/or implementing parts of Lisp 1.5 which I have not implemented), but this isn't intended to be a new language for doing real work; it's an educational and archaeological project, not serious engineering.
-Some `readline`-like functionality would be really useful, but my attempt to
-integrate [JLine](https://github.com/jline/jline3) has not (yet) been successful.
+Some `readline`-like functionality would be really useful, but my attempt to integrate [JLine](https://github.com/jline/jline3) has not (yet) been successful.
-An in-core structure editor would be an extremely nice thing, and I may well
-implement one.
+An in-core structure editor would be an extremely nice thing, and I may well implement one.
You are of course welcome to fork the project and do whatever you like with it!
@@ -110,53 +107,53 @@ now be possible to reimplement them as `FEXPRs` and so the reader macro function
| Function | Type | Signature | Implementation | Documentation |
|--------------|----------------|------------------|----------------|----------------------|
-| NIL | Lisp variable | ? | | see manual pages 22, 69 |
-| T | Lisp variable | ? | | see manual pages 22, 69 |
-| F | Lisp variable | ? | | see manual pages 22, 69 |
-| ADD1 | Host lambda function | ? | | ? |
-| AND | Host lambda function | ? | PREDICATE | `T` if and only if none of my `args` evaluate to either `F` or `NIL`, else `F`. In `beowulf.host` principally because I don't yet feel confident to define varargs functions in Lisp. |
-| APPEND | Lisp lambda function | ? | | see manual pages 11, 61 |
-| APPLY | Host lambda function | ? | | Apply this `function` to these `arguments` in this `environment` and return the result. For bootstrapping, at least, a version of APPLY written in Clojure. All args are assumed to be symbols or `beowulf.cons-cell/ConsCell` objects. See page 13 of the Lisp 1.5 Programmers Manual. |
-| ASSOC | Lisp lambda function, Host lambda function | ? | ? | If a is an association list such as the one formed by PAIRLIS in the above example, then assoc will produce the first pair whose first term is x. Thus it is a table searching function. All args are assumed to be `beowulf.cons-cell/ConsCell` objects. See page 12 of the Lisp 1.5 Programmers Manual. **NOTE THAT** this function is overridden by an implementation in Lisp, but is currently still present for bootstrapping. |
-| ATOM | Host lambda function | ? | PREDICATE | Returns `T` if and only if the argument `x` is bound to an atom; else `F`. It is not clear to me from the documentation whether `(ATOM 7)` should return `T` or `F`. I'm going to assume `T`. |
-| CAR | Host lambda function | ? | | Return the item indicated by the first pointer of a pair. NIL is treated specially: the CAR of NIL is NIL. |
-| CAAAAR | Lisp lambda function | ? | ? | ? |
-| CAAADR | Lisp lambda function | ? | ? | ? |
-| CAAAR | Lisp lambda function | ? | ? | ? |
-| CAADAR | Lisp lambda function | ? | ? | ? |
-| CAADDR | Lisp lambda function | ? | ? | ? |
-| CAADR | Lisp lambda function | ? | ? | ? |
-| CAAR | Lisp lambda function | ? | ? | ? |
-| CADAAR | Lisp lambda function | ? | ? | ? |
-| CADADR | Lisp lambda function | ? | ? | ? |
-| CADAR | Lisp lambda function | ? | ? | ? |
-| CADDAR | Lisp lambda function | ? | ? | ? |
-| CADDDR | Lisp lambda function | ? | ? | ? |
-| CADDR | Lisp lambda function | ? | ? | ? |
-| CADR | Lisp lambda function | ? | ? | ? |
-| CDAAAR | Lisp lambda function | ? | ? | ? |
-| CDAADR | Lisp lambda function | ? | ? | ? |
-| CDAAR | Lisp lambda function | ? | ? | ? |
-| CDADAR | Lisp lambda function | ? | ? | ? |
-| CDADDR | Lisp lambda function | ? | ? | ? |
-| CDADR | Lisp lambda function | ? | ? | ? |
-| CDAR | Lisp lambda function | ? | ? | ? |
-| CDDAAR | Lisp lambda function | ? | ? | ? |
-| CDDADR | Lisp lambda function | ? | ? | ? |
-| CDDAR | Lisp lambda function | ? | ? | ? |
-| CDDDAR | Lisp lambda function | ? | ? | ? |
-| CDDDDR | Lisp lambda function | ? | ? | ? |
-| CDDDR | Lisp lambda function | ? | ? | ? |
-| CDDR | Lisp lambda function | ? | ? | ? |
-| CDR | Host lambda function | ? | | Return the item indicated by the second pointer of a pair. NIL is treated specially: the CDR of NIL is NIL. |
-| CONS | Host lambda function | ? | | Construct a new instance of cons cell with this `car` and `cdr`. |
-| CONSP | Host lambda function | ? | ? | Return `T` if object `o` is a cons cell, else `F`. **NOTE THAT** this is an extension function, not available in strct mode. I believe that Lisp 1.5 did not have any mechanism for testing whether an argument was, or was not, a cons cell. |
-| COPY | Lisp lambda function | ? | | see manual pages 62 |
-| DEFINE | Host lambda function | ? | PSEUDO-FUNCTION | Bootstrap-only version of `DEFINE` which, post boostrap, can be overwritten in LISP. The single argument to `DEFINE` should be an association list of symbols to lambda functions. See page 58 of the manual. |
-| DIFFERENCE | Host lambda function | ? | | ? |
-| DIVIDE | Lisp lambda function | ? | | see manual pages 26, 64 |
-| DOC | Host lambda function | ? | ? | Open the page for this `symbol` in the Lisp 1.5 manual, if known, in the default web browser. **NOTE THAT** this is an extension function, not available in strct mode. |
-| EFFACE | Lisp lambda function | ? | PSEUDO-FUNCTION | see manual pages 63 |
+| NIL | Lisp variable | ? | | The canonical empty list. See manual pages 22, 69s |
+| T | Lisp variable | ? | | The canonical true value. See manual pages 22, 69 |
+| F | Lisp variable | ? | | The canonical false value. See manual pages 22, 69 |
+| ADD1 | Host lambda function | x:number | | Add one to the number `x`. |
+| AND | Host lambda function | expr* | PREDICATE | `T` if and only if none of my `args` evaluate to either `F` or `NIL`, else `F`.
In `beowulf.host` principally because I don't yet feel confident to define varargs functions in Lisp. |
+| APPEND | Lisp lambda function | ? | | see manual pages 11, 61 |
+| APPLY | Host lambda function | ? | | Apply this `function` to these `arguments` in this `environment` and return the result.
For bootstrapping, at least, a version of APPLY written in Clojure.
All args are assumed to be symbols or `beowulf.cons-cell/ConsCell` objects.
See page 13 of the Lisp 1.5 Programmers Manual. |
+| ASSOC | Lisp lambda function, Host lambda function | a:list | ? | If a is an association list such as the one formed by PAIRLIS in the above example, then assoc will produce the first pair whose first term is x. Thus it is a table searching function. All args are assumed to be `beowulf.cons-cell/ConsCell` objects. See page 12 of the Lisp 1.5 Programmers Manual.
**NOTE THAT** this function is overridden by an implementation in Lisp, but is currently still present for bootstrapping. |
+| ATOM | Host lambda function | x:expr | PREDICATE | Returns `T` if and only if the argument `x` is bound to an atom; else `F`. It is not clear to me from the documentation whether `(ATOM 7)` should return `T` or `F`. I'm going to assume `T`. |
+| CAR | Host lambda function | list | | Return the item indicated by the first pointer of a pair. NIL is treated specially: the CAR of NIL is NIL. |
+| CAAAAR | Lisp lambda function | list | ? | ? |
+| CAAADR | Lisp lambda function | list | ? | ? |
+| CAAAR | Lisp lambda function | list | ? | ? |
+| CAADAR | Lisp lambda function | list | ? | ? |
+| CAADDR | Lisp lambda function | list | ? | ? |
+| CAADR | Lisp lambda function | list | ? | ? |
+| CAAR | Lisp lambda function | list | ? | ? |
+| CADAAR | Lisp lambda function | list | ? | ? |
+| CADADR | Lisp lambda function | list | ? | ? |
+| CADAR | Lisp lambda function | list | ? | ? |
+| CADDAR | Lisp lambda function | list | ? | ? |
+| CADDDR | Lisp lambda function | list | ? | ? |
+| CADDR | Lisp lambda function | list | ? | ? |
+| CADR | Lisp lambda function | list | ? | ? |
+| CDAAAR | Lisp lambda function | list | ? | ? |
+| CDAADR | Lisp lambda function | list | ? | ? |
+| CDAAR | Lisp lambda function | list | ? | ? |
+| CDADAR | Lisp lambda function | list | ? | ? |
+| CDADDR | Lisp lambda function | list | ? | ? |
+| CDADR | Lisp lambda function | list | ? | ? |
+| CDAR | Lisp lambda function | list | ? | ? |
+| CDDAAR | Lisp lambda function | list | ? | ? |
+| CDDADR | Lisp lambda function | list | ? | ? |
+| CDDAR | Lisp lambda function | list | ? | ? |
+| CDDDAR | Lisp lambda function | list | ? | ? |
+| CDDDDR | Lisp lambda function | list | ? | ? |
+| CDDDR | Lisp lambda function | list | ? | ? |
+| CDDR | Lisp lambda function | list | ? | ? |
+| CDR | Host lambda function | list | | Return the item indicated by the second pointer of a pair. NIL is treated specially: the CDR of NIL is NIL. |
+| CONS | Host lambda function | expr, expr | | Construct a new instance of cons cell with this `car` and `cdr`. |
+| CONSP | Host lambda function | o:expr | ? | Return `T` if object `o` is a cons cell, else `F`.
**NOTE THAT** this is an extension function, not available in strict mode. I believe that Lisp 1.5 did not have any mechanism for testing whether an argument was, or was not, a cons cell. |
+| COPY | Lisp lambda function | ? | | see manual pages 62 |
+| DEFINE | Host lambda function | ? | PSEUDO-FUNCTION | Bootstrap-only version of `DEFINE` which, post boostrap, can be overwritten in LISP. The single argument to `DEFINE` should be an association list of symbols to lambda functions. See page 58 of the manual. |
+| DIFFERENCE | Host lambda function | x:number, y:number | | Returns the result of subtracting the number `y` from the number `x` |
+| DIVIDE | Lisp lambda function | x:number, y:number | | see manual pages 26, 64 |
+| DOC | Host lambda function | ? | ? | Open the page for this `symbol` in the Lisp 1.5 manual, if known, in the default web browser.
**NOTE THAT** this is an extension function, not available in strct mode. |
+| EFFACE | Lisp lambda function | ? | PSEUDO-FUNCTION | see manual pages 63 |
| ERROR | Host lambda function | ? | PSEUDO-FUNCTION | Throw an error |
| EQ | Host lambda function | ? | PREDICATE | Returns `T` if and only if both `x` and `y` are bound to the same atom, else `NIL`. |
| EQUAL | Host lambda function | ? | PREDICATE | This is a predicate that is true if its two arguments are identical S-expressions, and false if they are different. (The elementary predicate `EQ` is defined only for atomic arguments.) The definition of `EQUAL` is an example of a conditional expression inside a conditional expression. NOTE: returns `F` on failure, not `NIL` |
@@ -164,50 +161,50 @@ now be possible to reimplement them as `FEXPRs` and so the reader macro function
| FACTORIAL | Lisp lambda function | ? | ? | ? |
| FIXP | Host lambda function | ? | PREDICATE | ? |
| GENSYM | Host lambda function | ? | | Generate a unique symbol. |
-| GET | Host lambda function | ? | | From the manual: '`get` is somewhat like `prop`; however its value is car of the rest of the list if the `indicator` is found, and NIL otherwise.' It's clear that `GET` is expected to be defined in terms of `PROP`, but we can't implement `PROP` here because we lack `EVAL`; and we can't have `EVAL` here because both it and `APPLY` depends on `GET`. OK, It's worse than that: the statement of the definition of `GET` (and of) `PROP` on page 59 says that the first argument to each must be a list; But the in the definition of `ASSOC` on page 70, when `GET` is called its first argument is always an atom. Since it's `ASSOC` and `EVAL` which I need to make work, I'm going to assume that page 59 is wrong. |
+| GET | Host lambda function | ? | | From the manual: '`get` is somewhat like `prop`; however its value is car of the rest of the list if the `indicator` is found, and NIL otherwise.'
It's clear that `GET` is expected to be defined in terms of `PROP`, but we can't implement `PROP` here because we lack `EVAL`; and we can't have `EVAL` here because both it and `APPLY` depends on `GET`.
OK, It's worse than that: the statement of the definition of `GET` (and of) `PROP` on page 59 says that the first argument to each must be a list; But the in the definition of `ASSOC` on page 70, when `GET` is called its first argument is always an atom. Since it's `ASSOC` and `EVAL` which I need to make work, I'm going to assume that page 59 is wrong. |
| GREATERP | Host lambda function | ? | PREDICATE | ? |
| INTEROP | Host lambda function | ? | ? | ? |
| INTERSECTION | Lisp lambda function | ? | ? | ? |
-| LENGTH | Lisp lambda function | ? | | see manual pages 62 |
+| LENGTH | Lisp lambda function | ? | | see manual pages 62 |
| LESSP | Host lambda function | ? | PREDICATE | ? |
-| MAPLIST | Lisp lambda function | ? | FUNCTIONAL | see manual pages 20, 21, 63 |
-| MEMBER | Lisp lambda function | ? | PREDICATE | see manual pages 11, 62 |
-| MINUSP | Lisp lambda function | ? | PREDICATE | see manual pages 26, 64 |
-| NOT | Lisp lambda function | ? | PREDICATE | see manual pages 21, 23, 58 |
-| NULL | Lisp lambda function | ? | PREDICATE | see manual pages 11, 57 |
+| MAPLIST | Lisp lambda function | ? | FUNCTIONAL | see manual pages 20, 21, 63 |
+| MEMBER | Lisp lambda function | ? | PREDICATE | see manual pages 11, 62 |
+| MINUSP | Lisp lambda function | ? | PREDICATE | see manual pages 26, 64 |
+| NOT | Lisp lambda function | ? | PREDICATE | see manual pages 21, 23, 58 |
+| NULL | Lisp lambda function | ? | PREDICATE | see manual pages 11, 57 |
| NUMBERP | Host lambda function | ? | PREDICATE | ? |
-| OBLIST | Host lambda function | ? | | Return a list of the symbols currently bound on the object list. **NOTE THAT** in the Lisp 1.5 manual, footnote at the bottom of page 69, it implies that an argument can be passed but I'm not sure of the semantics of this. |
-| ONEP | Lisp lambda function | ? | PREDICATE | see manual pages 26, 64 |
-| OR | Host lambda function | ? | PREDICATE | `T` if and only if at least one of my `args` evaluates to something other than either `F` or `NIL`, else `F`. In `beowulf.host` principally because I don't yet feel confident to define varargs functions in Lisp. |
-| PAIR | Lisp lambda function | ? | | see manual pages 60 |
-| PAIRLIS | Lisp lambda function, Host lambda function | ? | ? | This function gives the list of pairs of corresponding elements of the lists `x` and `y`, and APPENDs this to the list `a`. The resultant list of pairs, which is like a table with two columns, is called an association list. Eessentially, it builds the environment on the stack, implementing shallow binding. All args are assumed to be `beowulf.cons-cell/ConsCell` objects. See page 12 of the Lisp 1.5 Programmers Manual. **NOTE THAT** this function is overridden by an implementation in Lisp, but is currently still present for bootstrapping. |
+| OBLIST | Host lambda function | ? | | Return a list of the symbols currently bound on the object list.
**NOTE THAT** in the Lisp 1.5 manual, footnote at the bottom of page 69, it implies that an argument can be passed but I'm not sure of the semantics of this. |
+| ONEP | Lisp lambda function | ? | PREDICATE | see manual pages 26, 64 |
+| OR | Host lambda function | ? | PREDICATE | `T` if and only if at least one of my `args` evaluates to something other than either `F` or `NIL`, else `F`.
In `beowulf.host` principally because I don't yet feel confident to define varargs functions in Lisp. |
+| PAIR | Lisp lambda function | ? | | see manual pages 60 |
+| PAIRLIS | Lisp lambda function, Host lambda function | ? | ? | This function gives the list of pairs of corresponding elements of the lists `x` and `y`, and APPENDs this to the list `a`. The resultant list of pairs, which is like a table with two columns, is called an association list. Essentially, it builds the environment on the stack, implementing shallow binding.
All args are assumed to be `beowulf.cons-cell/ConsCell` objects. See page 12 of the Lisp 1.5 Programmers Manual.
**NOTE THAT** this function is overridden by an implementation in Lisp, but is currently still present for bootstrapping. |
| PLUS | Host lambda function | ? | | ? |
| PRETTY | | ? | ? | ? |
-| PRINT | | ? | PSEUDO-FUNCTION | see manual pages 65, 84 |
-| PROG | Host nlambda function | ? | | The accursed `PROG` feature. See page 71 of the manual. Lisp 1.5 introduced `PROG`, and most Lisps have been stuck with it ever since. It introduces imperative programming into what should be a pure functional language, and consequently it's going to be a pig to implement. Broadly, `PROG` is a variadic pseudo function called as a `FEXPR` (or possibly an `FSUBR`, although I'm not presently sure that would even work.) The arguments, which are unevaluated, are a list of forms, the first of which is expected to be a list of symbols which will be treated as names of variables within the program, and the rest of which (the 'program body') are either lists or symbols. Lists are treated as Lisp expressions which may be evaulated in turn. Symbols are treated as targets for the `GO` statement. **GO:** A `GO` statement takes the form of `(GO target)`, where `target` should be one of the symbols which occur at top level among that particular invocation of `PROG`s arguments. A `GO` statement may occur at top level in a PROG, or in a clause of a `COND` statement in a `PROG`, but not in a function called from the `PROG` statement. When a `GO` statement is evaluated, execution should transfer immediately to the expression which is the argument list immediately following the symbol which is its target. If the target is not found, an error with the code `A6` should be thrown. **RETURN:** A `RETURN` statement takes the form `(RETURN value)`, where `value` is any value. Following the evaluation of a `RETURN` statement, the `PROG` should immediately exit without executing any further expressions, returning the value. **SET and SETQ:** In addition to the above, if a `SET` or `SETQ` expression is encountered in any expression within the `PROG` body, it should affect not the global object list but instead only the local variables of the program. **COND:** In **strict** mode, when in normal execution, a `COND` statement none of whose clauses match should not return `NIL` but should throw an error with the code `A3`... *except* that inside a `PROG` body, it should not do so. *sigh*. **Flow of control:** Apart from the exceptions specified above, expressions in the program body are evaluated sequentially. If execution reaches the end of the program body, `NIL` is returned. Got all that? Good. |
-| PROP | Lisp lambda function | ? | FUNCTIONAL | see manual pages 59 |
-| QUOTE | Lisp lambda function | ? | | see manual pages 10, 22, 71 |
-| QUOTIENT | Host lambda function | ? | | I'm not certain from the documentation whether Lisp 1.5 `QUOTIENT` returned the integer part of the quotient, or a realnum representing the whole quotient. I am for now implementing the latter. |
+| PRINT | | ? | PSEUDO-FUNCTION | see manual pages 65, 84 |
+| PROG | Host nlambda function | ? | | The accursed `PROG` feature. See page 71 of the manual.
Lisp 1.5 introduced `PROG`, and most Lisps have been stuck with it ever since. It introduces imperative programming into what should be a pure functional language, and consequently it's going to be a pig to implement. Broadly, `PROG` is a variadic pseudo function called as a `FEXPR` (or possibly an `FSUBR`, although I'm not presently sure that would even work.) The arguments, which are unevaluated, are a list of forms, the first of which is expected to be a list of symbols which will be treated as names of variables within the program, and the rest of which (the 'program body') are either lists or symbols. Lists are treated as Lisp expressions which may be evaulated in turn. Symbols are treated as targets for the `GO` statement.
- **GO:** A `GO` statement takes the form of `(GO target)`, where `target` should be one of the symbols which occur at top level among that particular invocation of `PROG`s arguments. A `GO` statement may occur at top level in a PROG, or in a clause of a `COND` statement in a `PROG`, but not in a function called from the `PROG` statement. When a `GO` statement is evaluated, execution should transfer immediately to the expression which is the argument list immediately following the symbol which is its target. If the target is not found, an error with the code `A6` should be thrown.
- **RETURN:** A `RETURN` statement takes the form `(RETURN value)`, where `value` is any value. Following the evaluation of a `RETURN` statement, the `PROG` should immediately exit without executing any further expressions, returning the value.
- **SET and SETQ:** In addition to the above, if a `SET` or `SETQ` expression is encountered in any expression within the `PROG` body, it should affect not the global object list but instead only the local variables of the program.
- **COND:** In **strict** mode, when in normal execution, a `COND` statement none of whose clauses match should not return `NIL` but should throw an error with the code `A3`... *except* that inside a `PROG` body, it should not do so. *sigh*.
**Flow of control:** Apart from the exceptions specified above, expressions in the program body are evaluated sequentially. If execution reaches the end of the program body, `NIL` is returned.
Got all that? Good. |
+| PROP | Lisp lambda function | ? | FUNCTIONAL | see manual pages 59 |
+| QUOTE | Lisp lambda function | ? | | see manual pages 10, 22, 71 |
+| QUOTIENT | Host lambda function | ? | | I'm not certain from the documentation whether Lisp 1.5 `QUOTIENT` returned the integer part of the quotient, or a realnum representing the whole quotient. I am for now implementing the latter. |
| RANGE | Lisp lambda function | ? | ? | ? |
| READ | Host lambda function | ? | PSEUDO-FUNCTION | An implementation of a Lisp reader sufficient for bootstrapping; not necessarily the final Lisp reader. `input` should be either a string representation of a LISP expression, or else an input stream. A single form will be read. |
| REMAINDER | Host lambda function | ? | | ? |
| REPEAT | Lisp lambda function | ? | ? | ? |
-| RPLACA | Host lambda function | ? | PSEUDO-FUNCTION | Replace the CAR pointer of this `cell` with this `value`. Dangerous, should really not exist, but does in Lisp 1.5 (and was important for some performance hacks in early Lisps) |
-| RPLACD | Host lambda function | ? | PSEUDO-FUNCTION | Replace the CDR pointer of this `cell` with this `value`. Dangerous, should really not exist, but does in Lisp 1.5 (and was important for some performance hacks in early Lisps) |
-| SEARCH | Lisp lambda function | ? | FUNCTIONAL | see manual pages 63 |
-| SET | Host lambda function | ? | PSEUDO-FUNCTION | Implementation of SET in Clojure. Add to the `oblist` a binding of the value of `var` to the value of `val`. NOTE WELL: this is not SETQ! |
+| RPLACA | Host lambda function | ? | PSEUDO-FUNCTION | Replace the `CAR` pointer of this `cell` with this `value`. Dangerous, should really not exist, but does in Lisp 1.5 (and was important for some performance hacks in early Lisps) |
+| RPLACD | Host lambda function | ? | PSEUDO-FUNCTION | Replace the `CDR` pointer of this `cell` with this `value`. Dangerous, should really not exist, but does in Lisp 1.5 (and was important for some performance hacks in early Lisps) |
+| SEARCH | Lisp lambda function | ? | FUNCTIONAL | see manual pages 63 |
+| SET | Host lambda function | ? | PSEUDO-FUNCTION | Implementation of SET in Clojure. Add to the `oblist` a binding of the value of `var` to the value of `val`.
**NOTE WELL**: this is not SETQ! |
| SUB1 | Lisp lambda function, Host lambda function | ? | | ? |
| SUB2 | Lisp lambda function | ? | ? | ? |
-| SUBLIS | Lisp lambda function | ? | | see manual pages 12, 61 |
-| SUBST | Lisp lambda function | ? | | see manual pages 11, 61 |
-| SYSIN | Host lambda function | ? | ? | Read the contents of the file at this `filename` into the object list. If the file is not a valid Beowulf sysout file, this will probably corrupt the system, you have been warned. File paths will be considered relative to the filepath set when starting Lisp. It is intended that sysout files can be read both from resources within the jar file, and from the file system. If a named file exists in both the file system and the resources, the file system will be preferred. **NOTE THAT** if the provided `filename` does not end with `.lsp` (which, if you're writing it from the Lisp REPL, it won't), the extension `.lsp` will be appended. **NOTE THAT** this is an extension function, not available in strct mode. |
-| SYSOUT | Host lambda function | ? | ? | Dump the current content of the object list to file. If no `filepath` is specified, a file name will be constructed of the symbol `Sysout` and the current date. File paths will be considered relative to the filepath set when starting Lisp. **NOTE THAT** this is an extension function, not available in strct mode. |
-| TERPRI | | ? | PSEUDO-FUNCTION | see manual pages 65, 84 |
+| SUBLIS | Lisp lambda function | ? | | see manual pages 12, 61 |
+| SUBST | Lisp lambda function | ? | | see manual pages 11, 61 |
+| SYSIN | Host lambda function | ? | ? | Read the contents of the file at this `filename` into the object list. If the file is not a valid Beowulf sysout file, this will probably corrupt the system, you have been warned. File paths will be considered relative to the filepath set when starting Lisp. It is intended that sysout files can be read both from resources within the jar file, and from the file system. If a named file exists in both the file system and the resources, the file system will be preferred.
**NOTE THAT** if the provided `filename` does not end with `.lsp` (which, if you're writing it from the Lisp REPL, it won't), the extension `.lsp` will be appended.
**NOTE THAT** this is an extension function, not available in strct mode. |
+| SYSOUT | Host lambda function | ? | ? | Dump the current content of the object list to file. If no `filepath` is specified, a file name will be constructed of the symbol `Sysout` and the current date. File paths will be considered relative to the filepath set when starting Lisp.
**NOTE THAT** this is an extension function, not available in strict mode. |
+| TERPRI | | ? | PSEUDO-FUNCTION | see manual pages 65, 84 |
| TIMES | Host lambda function | ? | | ? |
| TRACE | Host lambda function | ? | PSEUDO-FUNCTION | Add this `s` to the set of symbols currently being traced. If `s` is not a symbol or sequence of symbols, does nothing. |
| UNION | Lisp lambda function | ? | ? | ? |
-| UNTRACE | Host lambda function | ? | PSEUDO-FUNCTION | Remove this `s` from the set of symbols currently being traced. If `s` is not a symbol or sequence of symbols, does nothing. |
-| ZEROP | Lisp lambda function | ? | PREDICATE | see manual pages 26, 64 |
+| UNTRACE | Host lambda function | ? | PSEUDO-FUNCTION | Remove this `s` from the set of symbols currently being traced. If `s` is not a symbol or sequence of symbols, does nothing. |
+| ZEROP | Lisp lambda function | ? | PREDICATE | see manual pages 26, 64 |
Functions described as 'Lisp function' above are defined in the default
sysout file, `resources/lisp1.5.lsp`, which will be loaded by default unless
@@ -219,8 +216,7 @@ over the Clojure implementations.
### Architectural plan
-Not everything documented in this section is yet built. It indicates the
-direction of travel and intended destination, not the current state.
+Not everything documented in this section is yet built. It indicates the direction of travel and intended destination, not the current state.
#### resources/lisp1.5.lsp
diff --git a/docs/cloverage/beowulf/bootstrap.clj.html b/docs/cloverage/beowulf/bootstrap.clj.html
index 20afabb..c45387d 100644
--- a/docs/cloverage/beowulf/bootstrap.clj.html
+++ b/docs/cloverage/beowulf/bootstrap.clj.html
@@ -38,1213 +38,1237 @@
011 objects."
- 012 (:require [clojure.string :as s]
+ 012 (:require [beowulf.cons-cell :refer [F make-beowulf-list make-cons-cell
- 013 [clojure.tools.trace :refer :all]
+ 013 pretty-print T]]
- 014 [beowulf.cons-cell :refer [make-beowulf-list make-cons-cell NIL T F]]))
+ 014 [beowulf.host :refer [ASSOC ATOM CAAR CADAR CADDR CADR CAR CDR GET
+
+
+ 015 LIST NUMBERP PAIRLIS traced?]]
+
+
+ 016 [beowulf.oblist :refer [*options* NIL oblist]])
+
+
+ 017 (:import [beowulf.cons_cell ConsCell]
+
+
+ 018 [clojure.lang Symbol]))
- 015
+ 019
- 016 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+ 020 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
- 017 ;;;
+ 021 ;;;
- 018 ;;; This file is essentially Lisp as defined in Chapter 1 (pages 1-14) of the
-
-
- 019 ;;; Lisp 1.5 Programmer's Manual; that is to say, a very simple Lisp language,
-
-
- 020 ;;; which should, I believe, be sufficient in conjunction with the functions
-
-
- 021 ;;; provided by `beowulf.host`, be sufficient to bootstrap the full Lisp 1.5
-
-
- 022 ;;; interpreter.
+ 022 ;;; Copyright (C) 2022-2023 Simon Brooke
023 ;;;
- 024 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+ 024 ;;; This program is free software; you can redistribute it and/or
+
+
+ 025 ;;; modify it under the terms of the GNU General Public License
+
+
+ 026 ;;; as published by the Free Software Foundation; either version 2
+
+
+ 027 ;;; of the License, or (at your option) any later version.
+
+
+ 028 ;;;
+
+
+ 029 ;;; This program is distributed in the hope that it will be useful,
+
+
+ 030 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+
+
+ 031 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+
+
+ 032 ;;; GNU General Public License for more details.
+
+
+ 033 ;;;
+
+
+ 034 ;;; You should have received a copy of the GNU General Public License
+
+
+ 035 ;;; along with this program; if not, write to the Free Software
+
+
+ 036 ;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+
+ 037 ;;;
+
+
+ 038 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
- 025
-
-
- 026 (declare EVAL)
-
-
- 027
-
-
- 028 (def oblist
-
-
- 029 "The default environment."
-
-
- 030 (atom NIL))
-
-
- 031
-
-
- 032 (def ^:dynamic *options*
-
-
- 033 "Command line options from invocation."
-
-
- 034 {})
-
-
- 035
-
-
- 036 (defmacro NULL
-
-
- 037 "Returns `T` if and only if the argument `x` is bound to `NIL`; else `F`."
-
-
- 038 [x]
-
-
- 039 `(if (= ~x NIL) T F))
-
-
- 040
-
-
- 041 (defmacro ATOM
-
-
- 042 "Returns `T` if and only is the argument `x` is bound to and atom; else `F`.
-
-
- 043 It is not clear to me from the documentation whether `(ATOM 7)` should return
-
-
- 044 `T` or `F`. I'm going to assume `T`."
-
-
- 045 [x]
-
-
- 046 `(if (or (symbol? ~x) (number? ~x)) T F))
-
-
- 047
-
-
- 048 (defmacro ATOM?
-
-
- 049 "The convention of returning `F` from predicates, rather than `NIL`, is going
-
-
- 050 to tie me in knots. This is a variant of `ATOM` which returns `NIL`
-
-
- 051 on failure."
-
-
- 052 [x]
-
-
- 053 `(if (or (symbol? ~x) (number? ~x)) T NIL))
-
-
- 054
-
-
- 055 (defn CAR
-
-
- 056 "Return the item indicated by the first pointer of a pair. NIL is treated
-
-
- 057 specially: the CAR of NIL is NIL."
-
-
- 058 [x]
-
-
- 059 (cond
-
-
- 060 (= x NIL) NIL
-
-
- 061 (instance? beowulf.cons_cell.ConsCell x) (.CAR x)
-
-
- 062 :else
-
-
- 063 (throw
-
-
- 064 (Exception.
-
-
- 065 (str "Cannot take CAR of `" x "` (" (.getName (.getClass x)) ")")))))
-
-
- 066
-
-
- 067 (defn CDR
-
-
- 068 "Return the item indicated by the second pointer of a pair. NIL is treated
-
-
- 069 specially: the CDR of NIL is NIL."
-
-
- 070 [x]
-
-
- 071 (cond
-
-
- 072 (= x NIL) NIL
-
-
- 073 (instance? beowulf.cons_cell.ConsCell x) (.CDR x)
-
-
- 074 :else
-
-
- 075 (throw
-
-
- 076 (Exception.
-
-
- 077 (str "Cannot take CDR of `" x "` (" (.getName (.getClass x)) ")")))))
-
-
- 078
-
-
- 079 (defn uaf
-
-
- 080 "Universal access function; `l` is expected to be an arbitrary list, `path`
-
-
- 081 a (clojure) list of the characters `a` and `d`. Intended to make declaring
-
-
- 082 all those fiddly `#'c[ad]+r'` functions a bit easier"
-
-
- 083 [l path]
-
-
- 084 (cond
-
-
- 085 (= l NIL) NIL
+ 039
- 086 (empty? path) l
-
-
- 087 :else (case (last path)
-
-
- 088 \a (uaf (CAR l) (butlast path))
-
-
- 089 \d (uaf (CDR l) (butlast path)))))
+ 040 (declare APPLY EVAL prog-eval)
- 090
+ 041
-
- 091 (defn CAAR [x] (uaf x (seq "aa")))
-
-
- 092 (defn CADR [x] (uaf x (seq "ad")))
-
-
- 093 (defn CDDR [x] (uaf x (seq "dd")))
-
-
- 094 (defn CDAR [x] (uaf x (seq "da")))
+
+ 042 ;;;; The PROGram feature ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
- 095
-
-
- 096 (defn CAAAR [x] (uaf x (seq "aaa")))
-
-
- 097 (defn CAADR [x] (uaf x (seq "aad")))
-
-
- 098 (defn CADAR [x] (uaf x (seq "ada")))
-
-
- 099 (defn CADDR [x] (uaf x (seq "add")))
-
-
- 100 (defn CDDAR [x] (uaf x (seq "dda")))
-
-
- 101 (defn CDDDR [x] (uaf x (seq "ddd")))
-
-
- 102 (defn CDAAR [x] (uaf x (seq "daa")))
-
-
- 103 (defn CDADR [x] (uaf x (seq "dad")))
-
-
- 104
-
-
- 105 (defn CAAAAR [x] (uaf x (seq "aaaa")))
-
-
- 106 (defn CAADAR [x] (uaf x (seq "aada")))
-
-
- 107 (defn CADAAR [x] (uaf x (seq "adaa")))
-
-
- 108 (defn CADDAR [x] (uaf x (seq "adda")))
-
-
- 109 (defn CDDAAR [x] (uaf x (seq "ddaa")))
-
-
- 110 (defn CDDDAR [x] (uaf x (seq "ddda")))
-
-
- 111 (defn CDAAAR [x] (uaf x (seq "daaa")))
-
-
- 112 (defn CDADAR [x] (uaf x (seq "dada")))
-
-
- 113 (defn CAAADR [x] (uaf x (seq "aaad")))
-
-
- 114 (defn CAADDR [x] (uaf x (seq "aadd")))
-
-
- 115 (defn CADADR [x] (uaf x (seq "adad")))
-
-
- 116 (defn CADDDR [x] (uaf x (seq "addd")))
-
-
- 117 (defn CDDADR [x] (uaf x (seq "ddad")))
-
-
- 118 (defn CDDDDR [x] (uaf x (seq "dddd")))
-
-
- 119 (defn CDAADR [x] (uaf x (seq "daad")))
-
-
- 120 (defn CDADDR [x] (uaf x (seq "dadd")))
-
-
- 121
+ 043
- 122 (defn EQ
+ 044 (def find-target
-
- 123 "Returns `T` if and only if both `x` and `y` are bound to the same atom,
-
-
- 124 else `F`."
-
-
- 125 [x y]
-
-
- 126 (if (and (= (ATOM x) T) (= x y)) T F))
-
-
- 127
+
+ 045 (memoize
- 128 (defn EQUAL
+ 046 (fn [target body]
-
- 129 "This is a predicate that is true if its two arguments are identical
-
-
- 130 S-expressions, and false if they are different. (The elementary predicate
-
-
- 131 `EQ` is defined only for atomic arguments.) The definition of `EQUAL` is
-
-
- 132 an example of a conditional expression inside a conditional expression.
-
-
- 133
-
-
- 134 NOTE: returns `F` on failure, not `NIL`"
-
-
- 135 [x y]
+
+ 047 (loop [body' body]
- 136 (cond
+ 048 (cond
-
- 137 (= (ATOM x) T) (EQ x y)
+
+ 049 (= body' NIL) (throw (ex-info (str "Mislar GO miercels: `" target "`")
-
- 138 (= (EQUAL (CAR x) (CAR y)) T) (EQUAL (CDR x) (CDR y))
-
-
- 139 :else F))
-
-
- 140
-
-
- 141 (defn SUBST
+
+ 050 {:phase :lisp
- 142 "This function gives the result of substituting the S-expression `x` for
+ 051 :function 'PROG
- 143 all occurrences of the atomic symbol `y` in the S-expression `z`."
+ 052 :type :lisp
- 144 [x y z]
-
-
- 145 (cond
-
-
- 146 (= (EQUAL y z) T) x
-
-
- 147 (= (ATOM? z) T) z ;; NIL is a symbol
-
-
- 148 :else
-
-
- 149 (make-cons-cell (SUBST x y (CAR z)) (SUBST x y (CDR z)))))
-
-
- 150
-
-
- 151 (defn APPEND
-
-
- 152 "Append the the elements of `y` to the elements of `x`.
-
-
- 153
-
-
- 154 All args are assumed to be `beowulf.cons-cell/ConsCell` objects.
-
-
- 155 See page 11 of the Lisp 1.5 Programmers Manual."
-
-
- 156 [x y]
-
-
- 157 (cond
-
-
- 158 (= x NIL) y
-
-
- 159 :else
-
-
- 160 (make-cons-cell (CAR x) (APPEND (CDR x) y))))
-
-
- 161
-
-
- 162
-
-
- 163 (defn MEMBER
-
-
- 164 "This predicate is true if the S-expression `x` occurs among the elements
-
-
- 165 of the list `y`.
-
-
- 166
-
-
- 167 All args are assumed to be symbols or `beowulf.cons-cell/ConsCell` objects.
-
-
- 168 See page 11 of the Lisp 1.5 Programmers Manual."
-
-
- 169 [x y]
-
-
- 170 (cond
-
-
- 171 (= y NIL) F ;; NOTE: returns F on falsity, not NIL
-
-
- 172 (= (EQUAL x (CAR y)) T) T
-
-
- 173 :else (MEMBER x (CDR y))))
-
-
- 174
-
-
- 175 (defn PAIRLIS
-
-
- 176 "This function gives the list of pairs of corresponding elements of the
-
-
- 177 lists `x` and `y`, and APPENDs this to the list `a`. The resultant list
-
-
- 178 of pairs, which is like a table with two columns, is called an
-
-
- 179 association list.
-
-
- 180
-
-
- 181 Eessentially, it builds the environment on the stack, implementing shallow
-
-
- 182 binding.
-
-
- 183
-
-
- 184 All args are assumed to be `beowulf.cons-cell/ConsCell` objects.
-
-
- 185 See page 12 of the Lisp 1.5 Programmers Manual."
-
-
- 186 [x y a]
-
-
- 187 (cond
-
-
- 188 ;; the original tests only x; testing y as well will be a little more
-
-
- 189 ;; robust if `x` and `y` are not the same length.
-
-
- 190 (or (= NIL x) (= NIL y)) a
-
-
- 191 :else (make-cons-cell
-
-
- 192 (make-cons-cell (CAR x) (CAR y))
-
-
- 193 (PAIRLIS (CDR x) (CDR y) a))))
-
-
- 194
-
-
- 195 (defn ASSOC
-
-
- 196 "If a is an association list such as the one formed by PAIRLIS in the above
-
-
- 197 example, then assoc will produce the first pair whose first term is x. Thus
-
-
- 198 it is a table searching function.
-
-
- 199
-
-
- 200 All args are assumed to be `beowulf.cons-cell/ConsCell` objects.
-
-
- 201 See page 12 of the Lisp 1.5 Programmers Manual."
-
-
- 202 [x a]
-
-
- 203 (cond
-
-
- 204 (= NIL a) NIL ;; this clause is not present in the original but is added for
-
-
- 205 ;; robustness.
-
-
- 206 (= (EQUAL (CAAR a) x) T) (CAR a)
-
-
- 207 :else
-
-
- 208 (ASSOC x (CDR a))))
-
-
- 209
-
-
- 210 (defn- SUB2
-
-
- 211 "Internal to `SUBLIS`, q.v., which SUBSTitutes into a list from a store.
-
-
- 212 ? I think this is doing variable binding in the stack frame?"
-
-
- 213 [a z]
-
-
- 214 (cond
-
-
- 215 (= NIL a) z
-
-
- 216 (= (CAAR a) z) (CDAR a) ;; TODO: this looks definitely wrong
-
-
- 217 :else
-
-
- 218 (SUB2 (CDR a) z)))
-
-
- 219
-
-
- 220 (defn SUBLIS
-
-
- 221 "Here `a` is assumed to be an association list of the form
-
-
- 222 `((ul . vl)...(un . vn))`, where the `u`s are atomic, and `y` is any
-
-
- 223 S-expression. What `SUBLIS` does, is to treat the `u`s as variables when
-
-
- 224 they occur in `y`, and to SUBSTitute the corresponding `v`s from the pair
-
-
- 225 list.
-
-
- 226
-
-
- 227 My interpretation is that this is variable binding in the stack frame.
-
-
- 228
-
-
- 229 All args are assumed to be `beowulf.cons-cell/ConsCell` objects.
-
-
- 230 See page 12 of the Lisp 1.5 Programmers Manual."
-
-
- 231 [a y]
-
-
- 232 (cond
-
-
- 233 (= (ATOM? y) T) (SUB2 a y)
-
-
- 234 :else
-
-
- 235 (make-cons-cell (SUBLIS a (CAR y)) (SUBLIS a (CDR y)))))
-
-
- 236
-
-
- 237 (defn interop-interpret-q-name
-
-
- 238 "For interoperation with Clojure, it will often be necessary to pass
-
-
- 239 qualified names that are not representable in Lisp 1.5. This function
-
-
- 240 takes a sequence in the form `(PART PART PART... NAME)` and returns
-
-
- 241 a symbol in the form `PART.PART.PART/NAME`. This symbol will then be
-
-
- 242 tried in both that form and lower-cased. Names with hyphens or
-
-
- 243 underscores cannot be represented with this scheme."
-
-
- 244 [l]
+ 053 :code :A6
- 245 (if
-
-
- 246 (seq? l)
-
-
- 247 (symbol
-
-
- 248 (s/reverse
-
-
- 249 (s/replace-first
-
-
- 250 (s/reverse
-
-
- 251 (s/join "." (map str l)))
-
-
- 252 "."
-
-
- 253 "/")))
-
-
- 254 l))
-
-
- 255
-
-
- 256 (deftrace INTEROP
-
-
- 257 "Clojure (or other host environment) interoperation API. `fn-symbol` is expected
-
-
- 258 to be either
-
-
- 259
-
-
- 260 1. a symbol bound in the host environment to a function; or
-
-
- 261 2. a sequence (list) of symbols forming a qualified path name bound to a
-
-
- 262 function.
-
-
- 263
-
-
- 264 Lower case characters cannot normally be represented in Lisp 1.5, so both the
-
-
- 265 upper case and lower case variants of `fn-symbol` will be tried. If the
-
-
- 266 function you're looking for has a mixed case name, that is not currently
-
-
- 267 accessible.
-
-
- 268
-
-
- 269 `args` is expected to be a Lisp 1.5 list of arguments to be passed to that
-
-
- 270 function. Return value must be something acceptable to Lisp 1.5, so either
-
-
- 271 a symbol, a number, or a Lisp 1.5 list.
-
-
- 272
-
-
- 273 If `fn-symbol` is not found (even when cast to lower case), or is not a function,
-
-
- 274 or the value returned cannot be represented in Lisp 1.5, an exception is thrown
-
-
- 275 with `:cause` bound to `:interop` and `:detail` set to a value representing the
-
-
- 276 actual problem."
-
-
- 277 [fn-symbol args]
-
-
- 278 (let
-
-
- 279 [q-name (if
-
-
- 280 (seq? fn-symbol)
-
-
- 281 (interop-interpret-q-name fn-symbol)
-
-
- 282 fn-symbol)
-
-
- 283 l-name (symbol (s/lower-case q-name))
-
-
- 284 f (cond
-
-
- 285 (try
-
-
- 286 (fn? (eval l-name))
-
-
- 287 (catch java.lang.ClassNotFoundException e nil)) (eval l-name)
-
-
- 288 (try
-
-
- 289 (fn? (eval q-name))
-
-
- 290 (catch java.lang.ClassNotFoundException e nil)) (eval q-name)
-
-
- 291 :else (throw
-
-
- 292 (ex-info
-
-
- 293 (str "INTEROP: unknown function `" fn-symbol "`")
-
-
- 294 {:cause :interop
-
-
- 295 :detail :not-found
-
-
- 296 :name fn-symbol
-
-
- 297 :also-tried l-name})))
-
-
- 298 result (eval (cons f args))]
-
-
- 299 (cond
-
-
- 300 (instance? beowulf.cons_cell.ConsCell result) result
-
-
- 301 (seq? result) (make-beowulf-list result)
-
-
- 302 (symbol? result) result
-
-
- 303 (string? result) (symbol result)
-
-
- 304 (number? result) result
-
-
- 305 :else (throw
-
-
- 306 (ex-info
-
-
- 307 (str "INTEROP: Cannot return `" result "` to Lisp 1.5.")
-
-
- 308 {:cause :interop
-
-
- 309 :detail :not-representable
-
-
- 310 :result result})))))
-
-
- 311
-
-
- 312 (defn APPLY
-
-
- 313 "For bootstrapping, at least, a version of APPLY written in Clojure.
-
-
- 314 All args are assumed to be symbols or `beowulf.cons-cell/ConsCell` objects.
-
-
- 315 See page 13 of the Lisp 1.5 Programmers Manual."
-
-
- 316 [function args environment]
-
-
- 317 (cond
-
-
- 318 (=
-
-
- 319 (ATOM? function)
-
-
- 320 T)(cond
-
-
- 321 ;; TODO: doesn't check whether `function` is bound in the environment;
-
-
- 322 ;; we'll need that before we can bootstrap.
-
-
- 323 (= function 'CAR) (CAAR args)
-
-
- 324 (= function 'CDR) (CDAR args)
-
-
- 325 (= function 'CONS) (make-cons-cell (CAR args) (CADR args))
-
-
- 326 (= function 'ATOM) (if (ATOM? (CAR args)) T NIL)
-
-
- 327 (= function 'EQ) (if (= (CAR args) (CADR args)) T NIL)
-
-
- 328 :else
-
-
- 329 (APPLY
-
-
- 330 (EVAL function environment)
-
-
- 331 args
-
-
- 332 environment))
-
-
- 333 (= (first function) 'LAMBDA) (EVAL
-
-
- 334 (CADDR function)
-
-
- 335 (PAIRLIS (CADR function) args environment))
-
-
- 336 (= (first function) 'LABEL) (APPLY
-
-
- 337 (CADDR function)
-
-
- 338 args
-
-
- 339 (make-cons-cell
-
-
- 340 (make-cons-cell
-
-
- 341 (CADR function)
-
-
- 342 (CADDR function))
-
-
- 343 environment))))
-
-
- 344
-
-
- 345 (defn- EVCON
-
-
- 346 "Inner guts of primitive COND. All args are assumed to be
-
-
- 347 `beowulf.cons-cell/ConsCell` objects.
-
-
- 348 See page 13 of the Lisp 1.5 Programmers Manual."
-
-
- 349 [clauses env]
-
-
- 350 (if
-
-
- 351 (not= (EVAL (CAAR clauses) env) NIL)
-
-
- 352 (EVAL (CADAR clauses) env)
-
-
- 353 (EVCON (CDR clauses) env)))
-
-
- 354
-
-
- 355 (defn- EVLIS
-
-
- 356 "Map `EVAL` across this list of `args` in the context of this
-
-
- 357 `env`ironment.All args are assumed to be `beowulf.cons-cell/ConsCell` objects.
-
-
- 358 See page 13 of the Lisp 1.5 Programmers Manual."
-
-
- 359 [args env]
-
-
- 360 (cond
-
-
- 361 (= NIL args) NIL
-
-
- 362 :else
-
-
- 363 (make-cons-cell
-
-
- 364 (EVAL (CAR args) env)
-
-
- 365 (EVLIS (CDR args) env))))
-
-
- 366
-
-
- 367 (deftrace traced-eval
-
-
- 368 "Essentially, identical to EVAL except traced."
-
-
- 369 [expr env]
-
-
- 370 (cond
-
-
- 371 (=
-
-
- 372 (ATOM? expr) T)
-
-
- 373 (CDR (ASSOC expr env))
-
-
- 374 (=
-
-
- 375 (ATOM? (CAR expr))
+ 054 :target target}))
- 376 T)(cond
-
-
- 377 (= (CAR expr) 'QUOTE) (CADR expr)
-
-
- 378 (= (CAR expr) 'COND) (EVCON (CDR expr) env)
-
-
- 379 :else (APPLY
-
-
- 380 (CAR expr)
-
-
- 381 (EVLIS (CDR expr) env)
+ 055 (= (.getCar body') target) body'
- 382 env))
-
-
- 383 :else (APPLY
-
-
- 384 (CAR expr)
-
-
- 385 (EVLIS (CDR expr) env)
-
-
- 386 env)))
+ 056 :else (recur (.getCdr body')))))))
- 387
+ 057
- 388 (defn EVAL
+ 058 (defn- prog-cond
- 389 "For bootstrapping, at least, a version of EVAL written in Clojure.
+ 059 "Like `EVCON`, q.v. except using `prog-eval` instead of `EVAL` and not
- 390 All args are assumed to be symbols or `beowulf.cons-cell/ConsCell` objects.
+ 060 throwing an error if no clause matches."
- 391 See page 13 of the Lisp 1.5 Programmers Manual."
+ 061 [clauses vars env depth]
+
+
+ 062 (loop [clauses' clauses]
+
+
+ 063 (if-not (= clauses' NIL)
+
+
+ 064 (let [test (prog-eval (CAAR clauses') vars env depth)]
+
+
+ 065 (if (not (#{NIL F} test))
+
+
+ 066 (prog-eval (CADAR clauses') vars env depth)
+
+
+ 067 (recur (.getCdr clauses'))))
+
+
+ 068 NIL)))
+
+
+ 069
+
+
+ 070 (defn- merge-vars [vars env]
+
+
+ 071 (reduce
+
+
+ 072 #(make-cons-cell
+
+
+ 073 (make-cons-cell %2 (@vars %2))
+
+
+ 074 env)
+
+
+ 075 env
+
+
+ 076 (keys @vars)))
+
+
+ 077
+
+
+ 078 (defn prog-eval
- 392 [expr env]
+ 079 "Like `EVAL`, q.v., except handling symbols, and expressions starting
+
+
+ 080 `GO`, `RETURN`, `SET` and `SETQ` specially."
+
+
+ 081 [expr vars env depth]
- 393 (cond
-
-
- 394 (true? (:trace *options*))
+ 082 (cond
- 395 (traced-eval expr env)
+ 083 (number? expr) expr
-
- 396 (=
+
+ 084 (symbol? expr) (@vars expr)
-
- 397 (ATOM? expr) T)
-
-
- 398 (CDR (ASSOC expr env))
-
-
- 399 (=
-
-
- 400 (ATOM? (CAR expr))
-
-
- 401 T)(cond
-
-
- 402 (= (CAR expr) 'QUOTE) (CADR expr)
-
-
- 403 (= (CAR expr) 'COND) (EVCON (CDR expr) env)
-
-
- 404 :else (APPLY
+
+ 085 (instance? ConsCell expr) (case (.getCar expr)
- 405 (CAR expr)
+ 086 COND (prog-cond (.getCdr expr)
-
- 406 (EVLIS (CDR expr) env)
+
+ 087 vars env depth)
+
+
+ 088 GO (make-cons-cell
+
+
+ 089 '*PROGGO* (.getCar (.getCdr expr)))
+
+
+ 090 RETURN (make-cons-cell
+
+
+ 091 '*PROGRETURN*
+
+
+ 092 (prog-eval (.getCar (.getCdr expr))
+
+
+ 093 vars env depth))
+
+
+ 094 SET (let [v (CADDR expr)]
+
+
+ 095 (swap! vars
- 407 env))
+ 096 assoc
-
- 408 :else (APPLY
+
+ 097 (prog-eval (CADR expr)
+
+
+ 098 vars env depth)
+
+
+ 099 (prog-eval (CADDR expr)
+
+
+ 100 vars env depth))
+
+
+ 101 v)
+
+
+ 102 SETQ (let [v (CADDR expr)]
- 409 (CAR expr)
-
-
- 410 (EVLIS (CDR expr) env)
+ 103 (swap! vars
- 411 env)))
+ 104 assoc
+
+
+ 105 (CADR expr)
+
+
+ 106 (prog-eval v
+
+
+ 107 vars env depth))
+
+
+ 108 v)
+
+
+ 109 ;; else
+
+
+ 110 (beowulf.bootstrap/EVAL expr
+
+
+ 111 (merge-vars vars env)
+
+
+ 112 depth))))
- 412
+ 113
+
+
+ 114 (defn PROG
+
+
+ 115 "The accursed `PROG` feature. See page 71 of the manual.
+
+
+ 116
+
+
+ 117 Lisp 1.5 introduced `PROG`, and most Lisps have been stuck with it ever
+
+
+ 118 since. It introduces imperative programming into what should be a pure
+
+
+ 119 functional language, and consequently it's going to be a pig to implement.
+
+
+ 120
+
+
+ 121 Broadly, `PROG` is a variadic pseudo function called as a `FEXPR` (or
+
+
+ 122 possibly an `FSUBR`, although I'm not presently sure that would even work.)
- 413
+ 123
+
+
+ 124 The arguments, which are unevaluated, are a list of forms, the first of
+
+
+ 125 which is expected to be a list of symbols which will be treated as names
+
+
+ 126 of variables within the program, and the rest of which (the 'program body')
+
+
+ 127 are either lists or symbols. Lists are treated as Lisp expressions which
+
+
+ 128 may be evaulated in turn. Symbols are treated as targets for the `GO`
+
+
+ 129 statement.
+
+
+ 130
+
+
+ 131 **GO:**
+
+
+ 132 A `GO` statement takes the form of `(GO target)`, where
+
+
+ 133 `target` should be one of the symbols which occur at top level among that
+
+
+ 134 particular invocation of `PROG`s arguments. A `GO` statement may occur at
+
+
+ 135 top level in a PROG, or in a clause of a `COND` statement in a `PROG`, but
+
+
+ 136 not in a function called from the `PROG` statement. When a `GO` statement
+
+
+ 137 is evaluated, execution should transfer immediately to the expression which
+
+
+ 138 is the argument list immediately following the symbol which is its target.
- 414
+ 139
+
+
+ 140 If the target is not found, an error with the code `A6` should be thrown.
+
+
+ 141
+
+
+ 142 **RETURN:**
+
+
+ 143 A `RETURN` statement takes the form `(RETURN value)`, where
+
+
+ 144 `value` is any value. Following the evaluation of a `RETURN` statement,
+
+
+ 145 the `PROG` should immediately exit without executing any further
+
+
+ 146 expressions, returning the value.
+
+
+ 147
+
+
+ 148 **SET and SETQ:**
+
+
+ 149 In addition to the above, if a `SET` or `SETQ` expression is encountered
+
+
+ 150 in any expression within the `PROG` body, it should affect not the global
+
+
+ 151 object list but instead only the local variables of the program.
+
+
+ 152
+
+
+ 153 **COND:**
+
+
+ 154 In **strict** mode, when in normal execution, a `COND` statement none of
+
+
+ 155 whose clauses match should not return `NIL` but should throw an error with
+
+
+ 156 the code `A3`... *except* that inside a `PROG` body, it should not do so.
+
+
+ 157 *sigh*.
+
+
+ 158
+
+
+ 159 **Flow of control:**
+
+
+ 160 Apart from the exceptions specified above, expressions in the program body
+
+
+ 161 are evaluated sequentially. If execution reaches the end of the program
+
+
+ 162 body, `NIL` is returned.
+
+
+ 163
+
+
+ 164 Got all that?
+
+
+ 165
+
+
+ 166 Good."
+
+
+ 167 [program env depth]
+
+
+ 168 (let [trace (traced? 'PROG)
+
+
+ 169 vars (atom (reduce merge (map #(assoc {} % NIL) (.getCar program))))
+
+
+ 170 body (.getCdr program)
+
+
+ 171 targets (set (filter symbol? body))]
+
+
+ 172 (when trace (do
+
+
+ 173 (println "Program:")
+
+
+ 174 (pretty-print program))) ;; for debugging
+
+
+ 175 (loop [cursor body]
+
+
+ 176 (let [step (.getCar cursor)]
+
+
+ 177 (when trace (do (println "Executing step: " step)
+
+
+ 178 (println " with vars: " @vars)))
+
+
+ 179 (cond (= cursor NIL) NIL
+
+
+ 180 (symbol? step) (recur (.getCdr cursor))
+
+
+ 181 :else (let [v (prog-eval (.getCar cursor) vars env depth)]
+
+
+ 182 (when trace (println " --> " v))
+
+
+ 183 (if (instance? ConsCell v)
+
+
+ 184 (case (.getCar v)
+
+
+ 185 *PROGGO* (let [target (.getCdr v)]
+
+
+ 186 (if (targets target)
+
+
+ 187 (recur (find-target target body))
+
+
+ 188 (throw (ex-info (str "Uncynlic GO miercels `"
+
+
+ 189 target "`")
+
+
+ 190 {:phase :lisp
+
+
+ 191 :function 'PROG
+
+
+ 192 :args program
+
+
+ 193 :type :lisp
+
+
+ 194 :code :A6
+
+
+ 195 :target target
+
+
+ 196 :targets targets}))))
+
+
+ 197 *PROGRETURN* (.getCdr v)
+
+
+ 198 ;; else
+
+
+ 199 (recur (.getCdr cursor)))
+
+
+ 200 (recur (.getCdr cursor)))))))))
+
+
+ 201
+
+
+ 202 ;;;; Tracing execution ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+ 203
+
+
+ 204 (defn- trace-call
+
+
+ 205 "Show a trace of a call to the function named by this `function-symbol`
+
+
+ 206 with these `args` at this depth."
+
+
+ 207 [function-symbol args depth]
+
+
+ 208 (when (traced? function-symbol)
+
+
+ 209 (let [indent (apply str (repeat depth "-"))]
+
+
+ 210 (println (str indent "> " function-symbol " " args)))))
+
+
+ 211
+
+
+ 212 (defn- trace-response
+
+
+ 213 "Show a trace of this `response` from the function named by this
+
+
+ 214 `function-symbol` at this depth."
+
+
+ 215 [function-symbol response depth]
+
+
+ 216 (when (traced? function-symbol)
+
+
+ 217 (let [indent (apply str (repeat depth "-"))]
+
+
+ 218 (println (str "<" indent " " function-symbol " " response))))
+
+
+ 219 response)
+
+
+ 220
+
+
+ 221 (defn- value
+
+
+ 222 "Seek a value for this symbol `s` by checking each of these indicators in
+
+
+ 223 turn."
+
+
+ 224 ([s]
+
+
+ 225 (value s (list 'APVAL 'EXPR 'FEXPR 'SUBR 'FSUBR)))
+
+
+ 226 ([s indicators]
+
+
+ 227 (when (symbol? s)
+
+
+ 228 (first (remove #(= % NIL) (map #(GET s %)
+
+
+ 229 indicators))))))
+
+
+ 230
+
+
+ 231 ;;;; APPLY ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+ 232
+
+
+ 233 (defn try-resolve-subroutine
+
+
+ 234 "Attempt to resolve this `subr` with these `args`."
+
+
+ 235 [subr args]
+
+
+ 236 (when (and subr (not= subr NIL))
+
+
+ 237 (try @(resolve subr)
+
+
+ 238 (catch Throwable any
+
+
+ 239 (throw (ex-info "þegnung (SUBR) ne āfand"
+
+
+ 240 {:phase :apply
+
+
+ 241 :function subr
+
+
+ 242 :args args
+
+
+ 243 :type :beowulf}
+
+
+ 244 any))))))
+
+
+ 245
+
+
+ 246 (defn- apply-symbolic
+
+
+ 247 "Apply this `funtion-symbol` to these `args` in this `environment` and
+
+
+ 248 return the result."
+
+
+ 249 [^Symbol function-symbol args ^ConsCell environment depth]
+
+
+ 250 (trace-call function-symbol args depth)
+
+
+ 251 (let [lisp-fn (value function-symbol '(EXPR FEXPR))
+
+
+ 252 args' (cond (= NIL args) args
+
+
+ 253 (empty? args) NIL
+
+
+ 254 (instance? ConsCell args) args
+
+
+ 255 :else (make-beowulf-list args))
+
+
+ 256 subr (value function-symbol '(SUBR FSUBR))
+
+
+ 257 host-fn (try-resolve-subroutine subr args')
+
+
+ 258 result (cond (and lisp-fn
+
+
+ 259 (not= lisp-fn NIL)) (APPLY lisp-fn args' environment depth)
+
+
+ 260 host-fn (try
+
+
+ 261 (apply host-fn (when (instance? ConsCell args') args'))
+
+
+ 262 (catch Exception any
+
+
+ 263 (throw (ex-info (str "Uncynlic þegnung: "
+
+
+ 264 (.getMessage any))
+
+
+ 265 {:phase :apply
+
+
+ 266 :function function-symbol
+
+
+ 267 :args args
+
+
+ 268 :type :beowulf}
+
+
+ 269 any))))
+
+
+ 270 :else (ex-info "þegnung ne āfand"
+
+
+ 271 {:phase :apply
+
+
+ 272 :function function-symbol
+
+
+ 273 :args args
+
+
+ 274 :type :beowulf}))]
+
+
+ 275 (trace-response function-symbol result depth)
+
+
+ 276 result))
+
+
+ 277
+
+
+ 278 (defn APPLY
+
+
+ 279 "Apply this `function` to these `arguments` in this `environment` and return
+
+
+ 280 the result.
+
+
+ 281
+
+
+ 282 For bootstrapping, at least, a version of APPLY written in Clojure.
+
+
+ 283 All args are assumed to be symbols or `beowulf.cons-cell/ConsCell` objects.
+
+
+ 284 See page 13 of the Lisp 1.5 Programmers Manual."
+
+
+ 285 [function args environment depth]
+
+
+ 286 (trace-call 'APPLY (list function args environment) depth)
+
+
+ 287 (let [result (cond
+
+
+ 288 (= NIL function) (if (:strict *options*)
+
+
+ 289 NIL
+
+
+ 290 (throw (ex-info "NIL sí ne þegnung"
+
+
+ 291 {:phase :apply
+
+
+ 292 :function "NIL"
+
+
+ 293 :args args
+
+
+ 294 :type :beowulf})))
+
+
+ 295 (= (ATOM function) T) (apply-symbolic function args environment (inc depth))
+
+
+ 296 :else (case (first function)
+
+
+ 297 LABEL (APPLY
+
+
+ 298 (CADDR function)
+
+
+ 299 args
+
+
+ 300 (make-cons-cell
+
+
+ 301 (make-cons-cell
+
+
+ 302 (CADR function)
+
+
+ 303 (CADDR function))
+
+
+ 304 environment)
+
+
+ 305 depth)
+
+
+ 306 FUNARG (APPLY (CADR function) args (CADDR function) depth)
+
+
+ 307 LAMBDA (EVAL
+
+
+ 308 (CADDR function)
+
+
+ 309 (PAIRLIS (CADR function) args environment) depth)
+
+
+ 310 (throw (ex-info "Ungecnáwen wyrþan sí þegnung-weard"
+
+
+ 311 {:phase :apply
+
+
+ 312 :function function
+
+
+ 313 :args args
+
+
+ 314 :type :beowulf}))))]
+
+
+ 315 (trace-response 'APPLY result depth)
+
+
+ 316 result))
+
+
+ 317
+
+
+ 318 ;;;; EVAL ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+ 319
+
+
+ 320 (defn- EVCON
+
+
+ 321 "Inner guts of primitive COND. All `clauses` are assumed to be
+
+
+ 322 `beowulf.cons-cell/ConsCell` objects. Note that tests in Lisp 1.5
+
+
+ 323 often return `F`, not `NIL`, on failure. If no clause matches,
+
+
+ 324 then, strictly, we throw an error with code `:A3`.
+
+
+ 325
+
+
+ 326 See pages 13 and 71 of the Lisp 1.5 Programmers Manual."
+
+
+ 327 [clauses env depth]
+
+
+ 328 (loop [clauses' clauses]
+
+
+ 329 (if-not (= clauses' NIL)
+
+
+ 330 (let [test (EVAL (CAAR clauses') env depth)]
+
+
+ 331 (if (not (#{NIL F} test))
+
+
+ 332 ;; (and (not= test NIL) (not= test F))
+
+
+ 333 (EVAL (CADAR clauses') env depth)
+
+
+ 334 (recur (.getCdr clauses'))))
+
+
+ 335 (if (:strict *options*)
+
+
+ 336 (throw (ex-info "Ne ġefōg dǣl in COND"
+
+
+ 337 {:phase :eval
+
+
+ 338 :function 'COND
+
+
+ 339 :args (list clauses)
+
+
+ 340 :type :lisp
+
+
+ 341 :code :A3}))
+
+
+ 342 NIL))))
+
+
+ 343
+
+
+ 344 (defn- EVLIS
+
+
+ 345 "Map `EVAL` across this list of `args` in the context of this
+
+
+ 346 `env`ironment.All args are assumed to be `beowulf.cons-cell/ConsCell` objects.
+
+
+ 347 See page 13 of the Lisp 1.5 Programmers Manual."
+
+
+ 348 [args env depth]
+
+
+ 349 (cond
+
+
+ 350 (= NIL args) NIL
+
+
+ 351 :else
+
+
+ 352 (make-cons-cell
+
+
+ 353 (EVAL (CAR args) env depth)
+
+
+ 354 (EVLIS (CDR args) env depth))))
+
+
+ 355
+
+
+ 356 (defn- eval-symbolic
+
+
+ 357 [expr env depth]
+
+
+ 358 (let [v (ASSOC expr env)
+
+
+ 359 indent (apply str (repeat depth "-"))]
+
+
+ 360 (when (traced? 'EVAL)
+
+
+ 361 (println (str indent ": EVAL: sceald bindele: " (or v "nil"))))
+
+
+ 362 (if (instance? ConsCell v)
+
+
+ 363 (.getCdr v)
+
+
+ 364 (let [v' (value expr (list 'APVAL))]
+
+
+ 365 (when (traced? 'EVAL)
+
+
+ 366 (println (str indent ": EVAL: deóp bindele: (" expr " . " (or v' "nil") ")")))
+
+
+ 367 (if v'
+
+
+ 368 v'
+
+
+ 369 (throw (ex-info "Ne tácen-bindele āfand"
+
+
+ 370 {:phase :eval
+
+
+ 371 :function 'EVAL
+
+
+ 372 :args (list expr env depth)
+
+
+ 373 :type :lisp
+
+
+ 374 :code :A8})))))))
+
+
+ 375
+
+
+ 376 (defn EVAL
+
+
+ 377 "Evaluate this `expr` and return the result. If `environment` is not passed,
+
+
+ 378 it defaults to the current value of the global object list. The `depth`
+
+
+ 379 argument is part of the tracing system and should not be set by user code.
+
+
+ 380
+
+
+ 381 All args are assumed to be numbers, symbols or `beowulf.cons-cell/ConsCell`
+
+
+ 382 objects. However, if called with just a single arg, `expr`, I'll assume it's
+
+
+ 383 being called from the Clojure REPL and will coerce the `expr` to `ConsCell`."
+
+
+ 384 ([expr]
+
+
+ 385 (let [expr' (if (and (coll? expr) (not (instance? ConsCell expr)))
+
+
+ 386 (make-beowulf-list expr)
+
+
+ 387 expr)]
+
+
+ 388 (EVAL expr' NIL 0)))
+
+
+ 389 ([expr env depth]
+
+
+ 390 (trace-call 'EVAL (list expr env depth) depth)
+
+
+ 391 (let [result (cond
+
+
+ 392 (= NIL expr) NIL ;; it was probably a mistake to make Lisp
+
+
+ 393 ;; NIL distinct from Clojure nil
+
+
+ 394 (= (NUMBERP expr) T) expr
+
+
+ 395 (symbol? expr) (eval-symbolic expr env depth)
+
+
+ 396 (string? expr) (if (:strict *options*)
+
+
+ 397 (throw
+
+
+ 398 (ex-info
+
+
+ 399 (str "EVAL: strings not allowed in strict mode: \"" expr "\"")
+
+
+ 400 {:phase :eval
+
+
+ 401 :detail :strict
+
+
+ 402 :expr expr}))
+
+
+ 403 (symbol expr))
+
+
+ 404 (= (ATOM (CAR expr)) T) (case (CAR expr)
+
+
+ 405 COND (EVCON (CDR expr) env depth)
+
+
+ 406 FUNCTION (LIST 'FUNARG (CADR expr))
+
+
+ 407 PROG (PROG (CDR expr) env depth)
+
+
+ 408 QUOTE (CADR expr)
+
+
+ 409 ;; else
+
+
+ 410 (APPLY
+
+
+ 411 (CAR expr)
+
+
+ 412 (EVLIS (CDR expr) env depth)
+
+
+ 413 env
+
+
+ 414 depth))
+
+
+ 415 :else (APPLY
+
+
+ 416 (CAR expr)
+
+
+ 417 (EVLIS (CDR expr) env depth)
+
+
+ 418 env
+
+
+ 419 depth))]
+
+
+ 420 (trace-response 'EVAL result depth)
+
+
+ 421 result)))
+
+
+ 422