more stuff

.gitignore

@@ -0,0 +1,3 @@
+bin/blang
+build
+build/*

Makefile

@@ -0,0 +1,23 @@
+CC = cc
+CFLAGS = -g
+RM = rm -f
+TARGETS = bin/blang
+
+all: $(TARGETS)
+
+clean:
+	$(RM) $(TARGETS)
+
+build:
+	mkdir -p build
+
+build/libblang.o: build src/libblang.c src/libblang.h
+	$(CC) $(CFLAGS) -c -o $@ src/libblang.c
+
+build/main.o: build src/main.c
+	$(CC) $(CFLAGS) -c -o $@ src/main.c
+
+bin/blang: build/libblang.o build/main.o
+	$(CC) $(CFLAGS) -o $@ build/*.o
+
+.PHONY: all clean

README.md

@@ -12,21 +12,176 @@ the bang language
 
 Public domain. 2022 DTB.
 
-# Examples
+Bang language is an unpleasant toy designed to be used in the murderu.us IRC
+server, but easily adapted anywhere due to its simplicity both in terms of
+model and implementation.
 
-## true(1)
+## Glossary
+
+### chart
+
+The listing of the program currently running.
+This can be modified during runtime.
+
+### command
+
+A character that indicates what the bang language executor should do next.
+
+### comment
+
+Ornamental characters, i.e. in-code notes.
+
+Comments can start with `';'` (in which case they're discarded from the chart)
+or `'#'` (in which case they're kept on the chart).
+
+Comments end with `'!'` or `'\n'`.
+
+### hand
+
+The general-purpose register.
+
+### catch
+
+To set the hand to a value.
+
+### throw
+
+To set a value to the contents of the hand.
+
+## Reference
+
+All operations are one character long.
+When an unknown operation is executed the resulting behavior is undefined
+(and maliciously so; for example, execution can stop or garbage can be written
+to the chart).
+
+Operation mappings are based on ergonomics and history.
+`'&'` and `'*'` are taken from C.
+`'+'` and `'-'` are taken from Brainfuck.
+`'<'` and `'>'` are more or less taken from the Bourne shell.
+The general ergonomics of bang language are informed by the story of Mel,
+part of hacker folklore.
+
+### `'!'`
+
+No-op. Does nothing.
+`' '`, `'\n'`, `'\r'`, `'\t'`, and `'\v'` are all also no-ops
+\- keep this in mind when styling code that contains `'?'`!
+
+### `'#'`
+
+Denotes a comment.
+The contents of the comment are kept in the chart but not executed.
+
+### `';'`
+
+Denotes a comment.
+The contents of the comment are discarded from the chart before runtime.
+
+### `'^'` and `'%'`
+
+`'^'` palms the content of the location of the program to which chart points.
+`'%'` throws at that location.
+
+The following program prints "Hello, world!",
+by iterating over the program listing itself and terminating after printing a
+line feed (10 decimal in ASCII):
 ```
-^ ; initialize state to 0
-% ; store state (0) into *stack
-; stack is destroyed, state becomes the final value of *stack
-; when the stack is destroyed, the program exits with the value of state
-$
+!Hello, world!
+{
+&+*
+^>
+----------?};	subtract 10, if the value is non-zero return
+vv*
 ```
 
-## Hello world:
+### `'&'` and `'*'`
+
+`'&'` (et) palms the chart. `'*'` (splat) throws the chart.
+
+The following program rewrites itself during runtime, navigating the chart
+using et and splat. Keep in mind `'!'` must be followed by `';'` in comments
+to maintain chartlessness:
+
 ```
-; the <.> construct uses '<' to store the next value literally into state,
-; does so, and uses '>' to output state literally
-<H><e><l><l><o><,>< ><w><o><r><l><d><!><
->^%$
+!vv;	zero out hand
+{?>;	set return point; if hand is non-zero, print hand
+!&;	palm the chart
+++++*;	add 4 to palm; splat the new chart
+<!%;	write '!;' to the new chart position
+&++*;	palm the chart; add 2 to palm; splat the new chart
+<<%;	write '<' to the new chart position
+&+*;	advance the chart one space
+<
+%;	write '\n' to the new chart position
+&+*;	advance the chart one space
+<>%;	write '>' to the new chart position
+&+*;	advance the chart one space
+<v%;	write 'v' to the new chart position
+&+*;	advance the chart one space
+<v%;	write 'v' to the new chart position
+<!;	palm '!;'
+};	return
+```
+
+Right before the final `'}'`, the chart is the following:
+
+```
+!vv;	zero out hand
+{!>;	print hand
+<
+>;	palm `'\n'`; print hand
+vv*;	splat zero to chart
+
+The rest of the program isn't executed.
+```
+
+### `'<'` and `'>'`
+
+`'<'` palms the next character literal.
+
+`'>'` prints the literal contents of hand to standard output.
+
+The following program prints "Hello, world!" the easy way:
+
+```
+!<H><e><l><l><o><,>< ><w><o><r><l><d><!>v++++++++++>v*
+```
+
+This is a quine; a program that prints itself.
+
+```
+{&+*!^>v?}v*
+```
+
+The following program prints the printable ASCII space:
+
+```
+!^*{;	palm bang (the first printable ASCII char), splat
+&>+*;	et, throw onto screen, increment, splat
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------
+------;	subtract 126
+v?};	if hand == 0, return
+<
+>;	print newline
+vv*;	exit
 ```

bin/blangfile

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+blang "$(cat "$@")"

blang.c

@@ -1,42 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-
-static unsigned char get = 0;
-static unsigned char _stack[4];
-static unsigned char *stack = _stack;
-static unsigned char *state;
-
-int main(){
-	int c;
-	while((c = getchar()) != EOF){
-		if(stack == (unsigned char *)0)
-			return (char)state;
-		if(get){
-			state = (char *)c;
-			get = 0;
-			continue;
-		}
-		switch(c){
-	case ' ':
-	case '\n':
-	case '\r':
-	case '\t':
-	case '\v':
-		break;
-	case '!': state = stack; break;
-	case '$': stack = state; state = (char *)*_stack; break;
-	case '%': *stack = (char)state; break;
-	case '^': state = (char *)0; break;
-	case '+': ++(char)state; break;
-	case '-': --(char)state; break;
-	case '>': putchar((char)state); break;
-	case '<': get = 1; break;
-	case ':':
-		  while((c = getchar()) != '\n')
-			  if(c == EOF)
-				  goto fin;
-		  break;
-		}
-	}
-fin:	return 1;
-}

example/hello_world.blang

@@ -0,0 +1,2 @@
+<H><e><l><l><o><,>< ><w><o><r><l><d><!><
+>^*

example/meta_programming.blang

@@ -0,0 +1,18 @@
+^{?>!&++*<!%&++*<<%&+*<
+%&+*<>%&+*<^%<!}
+
+^;      zero out hand
+{?>;    set return point; if hand is non-zero, print hand
+!&++*;  palm the chart; add 2 to palm; splat the new chart
+<!%;    write '!' to the new chart position
+&++*;   palm the chart; add 2 to palm; splat the new chart
+<<%;    write '<' to the new chart position
+&+*;    advance the chart one space
+<
+%;      write '\n' to the new chart position
+&+*;    advance the chart one space
+<>%;    write '>' to the new chart position
+&+*;    advance the chart one space
+<^%;    write '^' to the new chart position
+<!;     palm '!'
+};      return

example/true.blang

@@ -0,0 +1,2 @@
+#!/usr/bin/env blangfile
+^*

src/libblang.c

@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libblang.h"
+
+/* assumes unmodified chart */
+void Chart_iron(struct State *s){
+	chart_t index;
+	chart_t lookahead;
+
+	index = s->chart;
+	while(*index != '\0'){
+		if(*index == ';'){
+			lookahead = index;
+			while(
+					*lookahead != '!'
+					&& *lookahead != '\n'
+					&& *lookahead != '\0'
+			)
+				++lookahead;
+		}
+		++index;
+	}
+}
+
+void Ops_bang(struct State *s){ return; } /* more like a whimper */
+void Ops_land(struct State *s){ return; }
+
+void Ops_snd(struct State *s)	{ *(s->chart) = s->hand; }
+void Ops_rcv(struct State *s)	{ s->hand = (hand_t)*(s->chart); }
+
+void Ops_et(struct State *s)	{ s->hand = (hand_t)s->chart; }
+void Ops_splat(struct State *s)	{ s->chart = (chart_t)s->hand; }
+
+void Ops_inc(struct State *s)	{ ++(s->hand); }
+void Ops_dec(struct State *s)	{ --(s->hand); }
+void Ops_invert(struct State *s){ s->hand = !s->hand; }
+
+void Ops_sail(struct State *s)	{
+	while(Ops_lookup(*(s->counter)) != Ops_land)
+		--*(s->counter);
+}
+
+void Ops_in(struct State *s)	{ s->hand = *++s->counter; }
+void Ops_out(struct State *s)	{ putc((char)s->hand, stdout); }
+
+void Ops_what(struct State *s)	{ s->counter += !s->hand; }
+
+void Ops_comment(struct State *s){
+	while(strchr(BLANG_COMMENT_END, *++s->counter) == NULL);
+}
+
+const struct {
+	unsigned char name;
+	void (*f)(struct State *);
+} OPS[] = {
+	{ '!', Ops_bang }, { ' ', Ops_bang }, { '\n', Ops_bang },
+	{ '\r', Ops_bang }, { '\t', Ops_bang }, { '\v', Ops_bang },
+	{ '%', Ops_snd }, { '^', Ops_rcv },
+	{ '&', Ops_et }, { '*', Ops_splat },
+	{ '+', Ops_inc }, { '-', Ops_dec }, { 'v', Ops_invert },
+	{ '{', Ops_land }, { '}', Ops_sail },
+	{ '<', Ops_in }, { '>', Ops_out },
+	{ '?', Ops_what },
+	{ ';', Ops_comment }, { '#', Ops_comment }
+};
+
+/* Slower than a switch, but you don't have to update it when you add new
+ * ops! */
+void (*Ops_lookup(char op))(struct State *){
+	size_t i;
+
+	for(i = 0; i < (sizeof OPS)/(sizeof *OPS); ++i)
+		if(op == OPS[i].name)
+			return OPS[i].f;
+	return NULL;
+}

src/libblang.h

@@ -0,0 +1,22 @@
+#if !defined _LIBBLANG_H
+#	define _LIBBLANG_H 1
+#	include <stdint.h>
+/* This has to be big enough to hold a char * without degradation.
+ * Adjust to architecture/system/environment/etc. */
+typedef uint64_t hand_t; 
+
+/* Holds *argv; will not change between environments. */
+typedef char *chart_t;
+
+struct State{
+	chart_t chart;
+	chart_t point;
+	chart_t counter;
+	hand_t hand;
+};
+
+/* Characters that end a comment. */
+#define BLANG_COMMENT_END "!\n"
+
+void (*Ops_lookup(char op))(struct State *);
+#endif

src/main.c

@@ -0,0 +1,23 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "libblang.h"
+
+int main(int argc, char **argv){
+	struct State s;
+	int c;
+	void (*op)(struct State *);
+
+	s.chart = argv[1];
+	s.counter = s.chart;
+
+	for(s.counter = s.chart; *s.counter != '!'; ++s.counter);
+
+	for(;; ++s.counter){
+		if(s.chart == (char *)0)
+			return (int)s.hand;
+		if((op = Ops_lookup(*s.counter)) != NULL)
+			op(&s);
+	}
+}