Merge pull request 'change memory model' (#1) from meta into main

Reviewed-on: #1

i am judge jury and executioner

.gitignore

@@ -1,2 +1,3 @@
-bin
-bin/*
+bin/blang
+build
+build/*

Makefile

@@ -7,10 +7,16 @@ all: $(TARGETS)
 clean:
 	$(RM) $(TARGETS)
 
-bin:
-	mkdir -p bin
+build:
+	mkdir -p build
 
-bin/blang: bin src/*.c
-	$(CC) $(CFLAGS) -o $@ src/*.c
+build/blang.o: build src/blang.c src/blang.h
+	$(CC) -c -o $@ src/blang.c
+
+build/ops.o: build src/blang.h src/ops.c src/ops.h
+	$(CC) -c -o $@ src/ops.c
+
+bin/blang: build/blang.o build/ops.o
+	$(CC) $(CFLAGS) -o $@ build/*.o
 
 .PHONY: all clean

README.md

@@ -12,21 +12,22 @@ the bang language
 
 Public domain. 2022 DTB.
 
-# Examples
+## Examples
 
-## true(1)
+### true(1)
 ```
-^ ; 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
-$
+; initialize hand to 0
+^
+
+; set the chart pointer to 0 - this destroys the chart
+; and the program exits with the value of the hand
+* 
 ```
 
-## Hello world:
+### Hello world:
 ```
-; the <.> construct uses '<' to store the next value literally into state,
-; does so, and uses '>' to output state literally
+; the <.> construct uses '<' to literally 'palm' the next value
+; (store into hand), does so, and uses '>' to 'toss' (output hand's value)
 <H><e><l><l><o><,>< ><w><o><r><l><d><!><
->^%$
+>^*
 ```

bin/blangfile

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

example/hello_world.blang

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

example/true.blang

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

src/blang.c

@@ -1,42 +1,24 @@
+#include <stdint.h>
 #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;
+#include "blang.h"
+#include "ops.h"
 
-int main(){
+int main(int argc, char **argv){
+	struct State s;
 	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 '+': ++state; break;
-	case '-': --state; break;
-	case '>': putchar((char)state); break;
-	case '<': get = 1; break;
-	case ':':
-		  while((c = getchar()) != '\n')
-			  if(c == EOF)
-				  goto fin;
-		  break;
-		}
+	void (*op)(struct State *);
+
+	s.chart = *(argv+1);
+	s.counter = s.chart;
+
+	for(s.counter = s.chart; ; ++s.counter){
+		if(s.chart == (char *)0)
+			return (int)s.hand;
+		if((op = Ops_lookup(*s.counter)) == NULL)
+			return 127;
+		else
+			op(&s);
 	}
-fin:	return 1;
 }

src/blang.h

@@ -0,0 +1,17 @@
+#if !defined _BLANG_H
+#	define _BLANG_H
+#	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;
+};
+#endif

src/ops.c

@@ -0,0 +1,112 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "blang.h"
+
+/* no-op */
+void Ops_bang(struct State *s){
+	return;
+}
+
+void Ops_percent(struct State *s){
+	*(s->chart) = s->hand;
+}
+
+void Ops_carat(struct State *s){
+	s->hand = 0;
+}
+
+void Ops_ampersand(struct State *s){
+	s->hand = (uint64_t)s->chart;
+}
+
+void Ops_splat(struct State *s){
+	s->chart = (char *)s->hand;
+}
+
+void Ops_plus(struct State *s){
+	++(s->hand);
+}
+
+void Ops_dash(struct State *s){
+	--(s->hand);
+}
+
+void Ops_lbrack(struct State *s){
+	s->point = s->counter;
+}
+
+void Ops_rbrack(struct State *s){
+	s->counter = s->point;
+}
+
+void Ops_left(struct State *s){
+	s->hand = *++s->counter;
+}
+
+void Ops_right(struct State *s){
+	putc((char)s->hand, stdout);
+}
+
+void Ops_what(struct State *s){
+	if(!s->hand)
+		++(s->counter);
+}
+
+void Ops_semi(struct State *s){
+	int c;
+
+	while(strchr("!\n", *++s->counter) == NULL);
+}
+
+void Ops_mirror(struct State *s){
+	s->hand = !s->hand;
+}
+
+void Ops_cross(struct State *s){
+	char *i;
+	i = s->chart;
+	s->chart = (char *)s->hand;
+	s->hand = (uint64_t)i;
+}
+
+const struct {
+	unsigned char name;
+	void (*f)(struct State *);
+} OPS[] = {
+	{ '#', Ops_semi },
+	{ '%', Ops_percent },
+	{ '^', Ops_carat },
+	{ '&', Ops_ampersand },
+	{ '*', Ops_splat },
+	{ '+', Ops_plus },
+	{ '-', Ops_dash },
+	{ '{', Ops_lbrack },
+	{ '}', Ops_rbrack },
+	{ ';', Ops_semi },
+	{ '>', Ops_right },
+	{ '<', Ops_left },
+	{ '?', Ops_what },
+	{ 'v', Ops_mirror },
+	{ 'x', Ops_cross },
+
+	/* no-ops */
+	{ '!', Ops_bang },
+	{ ' ', Ops_bang },
+	{ '\n', Ops_bang },
+	{ '\r', Ops_bang },
+	{ '\t', Ops_bang },
+	{ '\v', Ops_bang }
+};
+
+/* 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/ops.h

@@ -0,0 +1,4 @@
+#if !defined _BLANG_OPS
+#	define _BLANG_OPS 1
+void (*Ops_lookup(char op))(struct State *);
+#endif