2026-04-10 16:23:49 +02:00

311 lines
8.9 KiB
TypeScript

import { Def, Expr, Stmt } from "./ast.ts";
function appended<T>(vs: T[], v: T): T[] {
vs.push(v);
return vs;
}
export type Tok = {
ty: string;
text: string;
line: number;
};
export function tokenize(text: string): Tok[] {
return text
.replace(/\/\/[^\n]*/g, "")
.replace(/[\(\)\n]/g, " $& ")
.split(/[ \t\r]+/)
.filter((tok) => tok !== "")
.reduce<[{ tok: string; line: number }[], number]>(
([toks, line], tok) =>
tok != "\n"
? [appended(toks, { tok, line }), line]
: [toks, line + 1],
[[], 1],
)[0]
.map(({ tok, line }) => ({ ty: tok, text: tok, line }))
.map((tok) => {
if (/^[a-zA-Z_0-9]+$/.test(tok.text)) {
tok.ty = "ident";
}
return tok;
});
}
export type SExpr = {
line: number;
ty: "Ident" | "List";
ident?: string;
exprs?: SExpr[];
};
function parseSExpr(toks: Tok[]): [Tok[], SExpr | null] {
if (toks.length == 0) {
return [toks, null];
}
const line = toks[0].line;
if (toks[0].ty === "ident") {
const ident = toks[0].text;
return [toks.slice(1), { line, ty: "Ident", ident }];
} else if (toks[0].ty === "(") {
toks = toks.slice(1);
const exprs: SExpr[] = [];
while (toks.length != 0 && toks[0].ty !== ")") {
let expr: SExpr | null;
[toks, expr] = parseSExpr(toks);
if (!expr) {
throw new Error(`expected expression on line ${line}`);
}
exprs.push(expr);
}
if (toks.length == 0 || toks[0].ty != ")") {
throw new Error(
`expected ')' on line ${
toks.at(0)?.line ?? "(eof)"
}, '(' on line ${line}`,
);
}
return [toks.slice(1), { line, ty: "List", exprs }];
} else {
throw new Error(`malformed on line ${line}`);
}
}
export function parseSExprs(toks: Tok[]): SExpr[] {
const exprs: SExpr[] = [];
while (toks.length != 0) {
let expr: SExpr | null;
[toks, expr] = parseSExpr(toks);
exprs.push(expr!);
}
return exprs;
}
class SExprMatcher {
private failed = false;
private captures = new Map<string, SExpr>();
constructor(private s: SExpr) {}
match(): Record<string, SExpr> | null {
return this.failed ? null : Object.fromEntries(this.captures.entries());
}
ident(val?: string): this {
if (this.s.ty !== "Ident" || val && this.s.ident! !== val) {
this.failed = true;
return this;
}
return this;
}
list(length?: number): this {
if (
this.s.ty !== "List" || (length && this.s.exprs!.length !== length)
) {
this.failed = true;
return this;
}
return this;
}
at(idx: number, func?: (s: SExprMatcher) => SExprMatcher): this {
if (this.s.ty !== "List" || idx >= this.s.exprs!.length) {
this.failed = true;
return this;
}
if (func) {
const inner = new SExprMatcher(this.s.exprs![idx]);
func(inner);
for (const [key, val] of inner.captures.entries()) {
this.captures.set(key, val);
}
this.failed = this.failed || inner.failed;
}
return this;
}
all(func: (s: SExprMatcher) => SExprMatcher): this {
if (this.s.ty !== "List") {
this.failed = true;
return this;
}
for (const s1 of this.s.exprs!) {
const inner = new SExprMatcher(s1);
func(inner);
for (const [key, val] of inner.captures.entries()) {
this.captures.set(key, val);
}
}
return this;
}
capture(id: string): this {
this.captures.set(id, this.s);
return this;
}
}
export function parseAst(ss: SExpr[]): Def[] {
const defs: Def[] = [];
for (const s of ss) {
defs.push(parseDef(s));
}
return defs;
}
function parseDef(s: SExpr): Def {
const m = new SExprMatcher(s)
.list(5)
.at(0, (s) => s.ident("def"))
.at(1, (s) => s.ident().capture("ident"))
.at(2, (s) => s.all((s) => s.ident()).capture("inputs"))
.at(3, (s) => s.all((s) => s.ident()).capture("outputs"))
.at(4, (s) => s.list().capture("stmts"))
.match();
if (!m) {
throw new Error(`malformed def on line ${s.line}`);
}
return new Def(
s.line,
m.ident.ident!,
m.inputs.exprs!.map((s) => s.ident!),
m.outputs.exprs!.map((s) => s.ident!),
m.stmts.exprs!.map((s) => parseStmt(s)),
);
}
function parseStmt(s: SExpr): Stmt {
const set_match = new SExprMatcher(s)
.list(3)
.at(0, (s) => s.ident("set"))
.at(1, (s) => s.ident().capture("subject"))
.at(2, (s) => s.capture("expr"))
.match();
if (set_match) {
const m = set_match;
return new Stmt(
s.line,
{
tag: "Set",
subject: parseExpr(m.subject),
expr: parseExpr(m.expr),
},
);
}
const let_match = new SExprMatcher(s)
.list(3)
.at(0, (s) => s.ident("let"))
.at(1, (s) => s.all((s) => s.ident()).capture("idents"))
.at(2, (s) => s.capture("expr"))
.match();
if (let_match) {
const m = let_match;
return new Stmt(
s.line,
{
tag: "Let",
idents: m.idents.exprs!.map((s) => s.ident!),
expr: parseExpr(m.expr),
},
);
}
throw new Error(`malformed statement on line ${s.line}`);
}
function parseExpr(s: SExpr): Expr {
if (s.ty === "Ident") {
return new Expr(s.line, { tag: "Ident", ident: s.ident! });
} else if (s.ty === "List") {
if (s.exprs!.length === 0) {
throw new Error(`empty expression not allowed, on line ${s.line}`);
}
if (s.exprs![0].ty !== "Ident") {
throw new Error(`callee must be an identifier, on line ${s.line}`);
}
return new Expr(
s.line,
{
tag: "Call",
callee: parseExpr(s.exprs![0]),
args: s.exprs!.slice(1).map((s) => parseExpr(s)),
},
);
} else {
throw new Error(`expected expression, on line ${s.line}`);
}
}
export function resolve(defs: Def[]): Map<Def, Map<Expr, Sym>> {
const defSyms = new Map<string, Def>();
for (const def of defs) {
defSyms.set(def.ident, def);
}
const resols = new Map<Def, Map<Expr, Sym>>();
for (const def of defs) {
const defResolver = new DefResolver(def, defSyms);
defResolver.resolve();
resols.set(def, defResolver.resols);
}
return resols;
}
export type Sym =
| { tag: "Builtin" }
| { tag: "Input"; idx: number }
| { tag: "Output"; idx: number }
| { tag: "Node"; stmt: Stmt; idx: number }
| { tag: "Def"; def: Def };
class DefResolver {
private syms = new Map<string, Sym>([
["relay_default_off", { tag: "Builtin" }],
["relay_default_on", { tag: "Builtin" }],
["gnd", { tag: "Builtin" }],
["vin", { tag: "Builtin" }],
]);
public resols = new Map<Expr, Sym>();
constructor(private def: Def, private defSyms: Map<string, Def>) {}
resolve() {
for (const [idx, ident] of this.def.inputs.entries()) {
this.syms.set(ident, { tag: "Input", idx });
}
for (const [idx, ident] of this.def.outputs.entries()) {
this.syms.set(ident, { tag: "Output", idx });
}
const { syms, defSyms, resols } = this;
this.def.visit({
visitStmt(stmt) {
stmt.visitSubtree(this);
if (stmt.kind.tag === "Let") {
for (const [idx, ident] of stmt.kind.idents.entries()) {
syms.set(ident, { tag: "Node", stmt, idx });
}
}
return "stop";
},
visitExpr(expr) {
if (expr.kind.tag === "Ident") {
const sym = syms.get(expr.kind.ident);
if (sym) {
resols.set(expr, sym);
return;
}
const defSym = defSyms.get(expr.kind.ident);
if (defSym) {
resols.set(expr, { tag: "Def", def: defSym });
return;
}
throw new Error(
`unresolved identifier '${expr.kind.ident}', on line ${expr.line}`,
);
}
},
});
}
}