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Refactor so indentation handled by printer.
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@skaller
skaller committed Dec 16, 2022
1 parent 1613a28 commit ff15db4
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Showing 4 changed files with 115 additions and 116 deletions.
115 changes: 48 additions & 67 deletions mfront.flx
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Original file line number Diff line number Diff line change
Expand Up @@ -58,7 +58,6 @@ class stmt_parser {
proc prln(s:string) { write (io.out, s + "\n"); }

var counter = 0;
var indent = 0;
var ifelsestack = Empty[ifparity_t];
var label_counter = 2; // the first user label must be 2
var max_lab = (0,0); // error tracking: label index, line used
Expand Down Expand Up @@ -89,7 +88,6 @@ class stmt_parser {
h = head;
t = tail;

if h in ("else", "end") if indent > 0 perform --indent;
if h == "SWITCH" do
prln$ "push.1 # begin switch with PC = 1";
prln$ "pop.mem.0 # PC is memory location 0";
Expand All @@ -98,7 +96,6 @@ class stmt_parser {
prln$ "push.mem.0 # load PC";
prln$ "u32unchecked_add.1 # increment by 1";
prln$ "pop.mem.0 # save PC";
++indent;
elif h == "GOTO" do
advance;
checkint(h); // check the next token is an integer
Expand All @@ -116,19 +113,15 @@ class stmt_parser {
if labval != label_counter
perform fail ("Invalid label counter " + h ", should be " + label_counter.str);
++label_counter;
--indent;
prln$ "# LABEL " + h;
if switch_counter > 2 perform
prln$ "else # end case " + (switch_counter - 1).str;
prln$ "u32checked_eq."+h+ " # check if PC is for this case";
prln$ "if.true # start code for this case";
++indent;
++switch_counter; // count the number of 'end' we need at the switch end
elif h == "BREAK" do
--indent;
prln$ "push.0 # 0";
prln$ "pop.mem.0 # ->PC";
++indent;

elif h == "ENDSWITCH" do
if max_lab.0 > switch_counter perform
Expand All @@ -138,7 +131,6 @@ class stmt_parser {
prln$ "end # switch case "+switch_counter.str;
--switch_counter;
done
--indent;
prln$ "push.mem.0 #load PC";
prln$ "dup";
prln$ "u32checked_eq.0"; // test for break
Expand All @@ -150,13 +142,13 @@ class stmt_parser {
// eval
elif h == "eval" do
var e,rest = expr_parser::parse_expr t;
prln$ " " * indent + "# " + line;
prln$ "# " + line;
//prln$ "# eval[parsed] " e.str;
pr$ symtab&.expr_emit::postfix e indent;
pr$ symtab&.expr_emit::postfix e;

// let
elif h == "let" do
prln$ " " * indent + "# " + line;
prln$ "# " + line;
advance;
var mut = false;
if h == "mut" do
Expand All @@ -173,8 +165,8 @@ class stmt_parser {
var e2,rest2 = expr_parser::parse_expr t;
//prln$ "# eval[inp] " + cat " " tokens;
//prln$ "# eval[parsed] " + e2.str;
pr$ symtab&.expr_emit::postfix e2 indent;
prln$ " " * indent + "pop.local." + symtab&.get_address name +"# init " + name;
pr$ symtab&.expr_emit::postfix e2 ;
prln$ "pop.local." + symtab&.get_address name +"# init " + name;

// assignment (requires "assign" binder)

Expand All @@ -183,29 +175,25 @@ class stmt_parser {
name = h;
advance;
e,rest = expr_parser::parse_expr t;
pr$ symtab&.expr_emit::postfix e indent;
pr$ symtab&.expr_emit::postfix e ;
var sym = symtab&.get_info name;
if not sym.mut do
fail("Write to immutable variable " + name);
done
prln$ " " * indent + "pop.local." + sym.loc.str + "# " + name + "<-";
prln$ "pop.local." + sym.loc.str + "# " + name + "<-";

elif h == "while" do
chainmatch t with
| [".","true"] =>
prln$ " " * indent + "while.true # Miden"; // miden while.true
prln$ "while.true # Miden"; // miden while.true
ormatch unbox t.rev with
| Cons ("{", tail) =>
t = tail.rev;
// evaluate condition
e,rest = expr_parser::parse_expr t;
pr$ symtab&.expr_emit::postfix e indent;
prln(" " * indent + "while.true # Rust while");
pr$ symtab&.expr_emit::postfix e ;
prln("while.true # Rust while");
ifelsestack = Cons(whileblock,ifelsestack);
// NOTE: at the end, a leading if indents already
// this currently applies to both miden "if" and a Rust "if"
// HACK!!!!
//++indent;
| _ => fail ("while requires trailing {");
endmatch;

Expand Down Expand Up @@ -240,19 +228,15 @@ class stmt_parser {
elif h == "if" do
chainmatch t with
| [".","true"] =>
prln$ " " * indent + "if.true # Miden"; // miden if.true
prln$ "if.true # Miden"; // miden if.true
ormatch unbox t.rev with
| Cons ("{", tail) =>
t = tail.rev;
// evaluate condition
e,rest = expr_parser::parse_expr t;
pr$ symtab&.expr_emit::postfix e indent;
prln(" " * indent + "if.true # Rust if");
pr$ symtab&.expr_emit::postfix e ;
prln("if.true # Rust if");
ifelsestack = Cons(ifblock 1,ifelsestack);
// NOTE: at the end, a leading if indents already
// this currently applies to both miden "if" and a Rust "if"
// HACK!!!!
//++indent;
| _ => fail ("if requires trailing {");
endmatch;
// end an if or else block and maybe start a new if
Expand All @@ -266,22 +250,19 @@ class stmt_parser {
ifelsestack = stk; // terminate ifelse block (no matching else)
var nest = n;
while nest > 0 do
--indent;
prln$ " " * indent + "end # Rust endif";
prln$ "end # Rust endif";
--nest;
done
| Cons(elseblock n,stk) =>
ifelsestack = stk; // terminate ifelse block else
nest = n;
while nest > 0 do
--indent;
prln$ " " * indent + "end # Rust endif";
prln$ "end # Rust endif";
--nest;
done
| Cons(whileblock,stk) =>
--indent;
ifelsestack = stk; // terminate while block (no matching else)
prln$ " " * indent + "end # Rust endwhile";
prln$ "end # Rust endwhile";
endmatch;

| "else" => // switch nearest enclosing if to else
Expand All @@ -293,9 +274,7 @@ class stmt_parser {
| Cons(elseblock n,stk) => fail("Unmatched else");
| Cons(ifblock n,stk) =>
ifelsestack = Cons (elseblock n, stk);
--indent;
prln$ " " * indent + "else # Rust else";
++indent;
prln$ "else # Rust else";
endmatch;

| "if" => // chained if
Expand All @@ -304,28 +283,20 @@ class stmt_parser {
| Cons(elseblock n,stk) => fail("Unmatched else if");
| Cons(ifblock n,stk) =>
ifelsestack = Cons (ifblock (n+1), stk);
--indent;
prln$ " " * indent + "else # Rust else if";
++indent;
prln$ "else # Rust else if";
// evaluate condition
e,rest = expr_parser::parse_expr t;
pr$ symtab&.expr_emit::postfix e indent;
prln(" " * indent + "if.true # Rust else if");
++indent;
pr$ symtab&.expr_emit::postfix e ;
prln("if.true # Rust else if");
endmatch; // ifelse
endmatch; // else
endmatch; // leading } symbol
else
prln$ " " * indent + cat "" tokens;
prln$ cat "" tokens;
done

| _ => ;
endmatch;
match tokens with
| Cons (head, tail) =>
if head in ("begin", "proc", "if", "else", "while", "repeat") perform ++indent;
| _ => ;
endmatch;
done
}
}
Expand All @@ -335,7 +306,29 @@ chip printer
connector io
pin inp : %< string
{
fun align_comments(line:string):string {
match find(line, char "#") with
| None => var out = line;
| Some k =>
var l = line.[to k];
var r = line.[k to];
if l.len.int > 32 do
l= l+ " ";
else
l = (l.rstrip + " " * 35).[0 to 35];
done
if r.len.int > 0 do
out = l + r;
else
out = l;
done
endmatch;
return out;
}

var x = "";
var indent = 0;

while true do
var s = read io.inp;
x += s;
Expand All @@ -344,23 +337,11 @@ chip printer
for(var i = 0; i<n; ++i;) do
var line = head xs;
xs = tail xs;
match find(line, char "#") with
| None => ;
| Some k =>
var l = line.[to k];
var r = line.[k to];
if l.len.int > 32 do
l= l+ " ";
else
l = (l.rstrip + " " * 35).[0 to 35];
done
if r.len.int > 0 do
line = l + r;
else
line = l;
done
endmatch;
println line;
if startswith line "end" or startswith line "else" perform --indent;
var indented_line = " " * indent + line;
var outline = align_comments indented_line;
if startswith line "while.true" or startswith line "if.true" or startswith line "else" perform ++indent;
println$ outline;
done
x = head xs;
done
Expand Down
12 changes: 6 additions & 6 deletions mfront_expr.flx
View file
Original file line number Diff line number Diff line change
Expand Up @@ -248,24 +248,24 @@ class expr_parser {
class expr_emit {
open expr_sym;

fun postfix (ps: &symbol::symbol_table_t) (e:expr) (indent: int) : string =>
let fun pf(e:expr):string => postfix ps e indent in
fun postfix (ps: &symbol::symbol_table_t) (e:expr) : string =>
let fun pf(e:expr):string => postfix ps e in
match e with
| Const s => " " * indent + "push."+s+" # "+s+"\n"
| Ident s => let a = ps.symbol::get_address s in " " * indent + "push.local."+a.str+" # <-" + s+"\n"
| Const s => "push."+s+" # "+s+"\n"
| Ident s => let a = ps.symbol::get_address s in "push.local."+a.str+" # <-" + s+"\n"
| Error => "ERROR\n"

| Binop (op, a, b) =>
let op = match binop_map.get op with
| None => "# Can't find '" + op "' in operator map\n"
| Some x => " " * indent + x
| Some x => x
in
pf a + pf b + op

| Unop (op, a) =>
let op = match unop_map.get op with
| None => "# Can't find '" + op "' in operator map\n"
| Some x => " " * indent + x
| Some x => x
in
pf a + op
;
Expand Down

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