Commit 995e7123 authored by psf's avatar psf
Browse files

recursion and iteration

parent c4f7fa6b
......@@ -2,7 +2,7 @@ use std::io;
use std::convert::TryInto;
//const CORE_SIZE: usize = 65408
const CORE_SIZE: usize = 256;
const CORE_SIZE: usize = 512;
#[derive(Debug, Eq, PartialEq)]
enum State {
......@@ -55,7 +55,7 @@ struct TableEntry {
immediate: bool
}
const PRIMITIVES: [TableEntry; 24] = [
const PRIMITIVES: [TableEntry; 27] = [
TableEntry {f: ret , name: None, immediate: false},
TableEntry {f: lit , name: None, immediate: false},
TableEntry {f: add , name: Some(ShortName {bytes: *b"+ ", length: 1}), immediate: false},
......@@ -68,17 +68,20 @@ const PRIMITIVES: [TableEntry; 24] = [
TableEntry {f: dup , name: Some(ShortName {bytes: *b"dup", length: 3}), immediate: false},
TableEntry {f: dump , name: Some(ShortName {bytes: *b"dum", length: 4}), immediate: false},
TableEntry {f: from_r_d, name: Some(ShortName {bytes: *b"r> ", length: 2}), immediate: false},
TableEntry {f: if_skip ,name: Some(ShortName {bytes: *b"? ", length: 1}), immediate: false},
TableEntry {f: immediate,name: Some(ShortName {bytes: *b"imm", length: 9}), immediate: false},
TableEntry {f: lbracket, name: Some(ShortName {bytes: *b"[ ", length: 1}), immediate: true},
TableEntry {f: load , name: Some(ShortName {bytes: *b"@ ", length: 1}), immediate: false},
TableEntry {f: mul , name: Some(ShortName {bytes: *b"* ", length: 1}), immediate: false},
TableEntry {f: ret_d , name: Some(ShortName {bytes: *b"ret", length: 3}), immediate: false},
TableEntry {f: rbracket, name: Some(ShortName {bytes: *b"] ", length: 1}), immediate: false},
TableEntry {f: smudge , name: Some(ShortName {bytes: *b"smu", length: 6}), immediate: false},
TableEntry {f: store , name: Some(ShortName {bytes: *b"! ", length: 1}), immediate: false},
TableEntry {f: sub , name: Some(ShortName {bytes: *b"- ", length: 1}), immediate: false},
TableEntry {f: swap , name: Some(ShortName {bytes: *b"swa", length: 4}), immediate: false},
TableEntry {f: tick , name: Some(ShortName {bytes: *b"' ", length: 1}), immediate: false},
TableEntry {f: to_r_d , name: Some(ShortName {bytes: *b">r ", length: 2}), immediate: false},
TableEntry {f: unsmudge, name: Some(ShortName {bytes: *b"uns", length: 8}), immediate: false},
TableEntry {f: word , name: Some(ShortName {bytes: *b"wor", length: 4}), immediate: false}
];
......@@ -147,7 +150,11 @@ fn init_dictionary(c: &mut Core) {
}
fn smudge(c: &mut Core) {
c.ram[(c.dp as usize) + 2] ^= 0x40;
c.ram[(c.dp as usize) + 2] |= 0x40;
}
fn unsmudge(c: &mut Core) {
c.ram[(c.dp as usize) + 2] &= 0xbf;
}
fn immediate(c: &mut Core) {
......@@ -282,43 +289,14 @@ fn ret_d(c: &mut Core) {
ret(c);
}
// --- Inner interpreter ---
fn fetch(c: &mut Core) -> u16 {
let ip = c.ip as usize;
let opcode = u16::from_le_bytes(c.ram[ip..=ip+1].try_into().unwrap());
c.ip += 2;
return opcode;
// --- Control flow ---
fn if_skip(c: &mut Core) {
let truthy = pop(c);
let retaddr = from_r(c);
to_r(c, retaddr + if truthy == 0 { 2 } else { 0 });
}
fn execute(c: &mut Core, opcode: u16) {
let primitive_index = (65535 - opcode) as usize;
if primitive_index < PRIMITIVES.len() {
(PRIMITIVES[primitive_index].f)(c);
} else {
// call
to_r(c, c.ip);
c.ip = opcode;
}
}
fn step(c: &mut Core) {
let opcode = fetch(c);
execute(c, opcode);
}
fn inner(c: &mut Core) {
loop {
step(c);
println!("ip={} trs={}", c.ip, c.trs);
if c.trs == 0 {
break;
}
}
}
// --- Math ---
// --- I/O ---
fn dot(c: &mut Core) {
print!("{} ", pop(c));
}
......@@ -337,6 +315,8 @@ fn word(c: &mut Core) {
}
}
// --- Math and logic ---
// note: this is an inline primitive, not a dict entry
fn lit(c: &mut Core) {
let ip = c.ip as usize;
......@@ -368,6 +348,42 @@ fn div(c: &mut Core) {
push(c, v2.saturating_div(v1));
}
// --- Inner interpreter ---
fn fetch(c: &mut Core) -> u16 {
let ip = c.ip as usize;
let opcode = u16::from_le_bytes(c.ram[ip..=ip+1].try_into().unwrap());
c.ip += 2;
return opcode;
}
fn execute(c: &mut Core, opcode: u16) {
let primitive_index = (65535 - opcode) as usize;
if primitive_index < PRIMITIVES.len() {
(PRIMITIVES[primitive_index].f)(c);
} else {
// call
to_r(c, c.ip);
c.ip = opcode;
}
}
fn step(c: &mut Core) {
let opcode = fetch(c);
execute(c, opcode);
}
fn inner(c: &mut Core) {
loop {
step(c);
//println!("ip={} trs={}", c.ip, c.trs);
if c.trs == 0 {
break;
}
}
}
// --- Outer interpreter ---
fn lbracket(c: &mut Core) {
......@@ -446,6 +462,16 @@ fn main() {
}
}
// create : ] create ] [ 65535 ,
// create ; ] 65535 , [ ' [ , 65535 , immediate
// : dog 33 . ;
/*
create dog ] r> drop dup . 1 - dup ? dog ret [
create dog smudge ] dog ret [ smudge
100 dog
create : ] create smudge ] [ 65535 ,
create ; ] unsmudge 65535 , [ ' [ , 65535 , immediate
: dog 33 . ;
: dog [ unsmudge ] r> drop dup . 1 - dup ? dog ;
: dog dog ;
100 dog
*/
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