preserves/implementations/javascript/packages/schema/src/compiler/gentype.ts

98 lines
3.5 KiB
TypeScript

import * as M from "../meta";
import { ANY_TYPE, FieldType, FieldMap, SimpleType, Type } from "./type";
export type RefResolver = (ref: M.Ref) => FieldType;
export function typeForDefinition(resolver: RefResolver, d: M.Definition): Type {
switch (d._variant) {
case 'or':
return Type.union(
new Map([d.pattern0, d.pattern1, ... d.patternN].map(a =>
[a.variantLabel, typeFor(resolver, a.pattern)])));
case 'and':
return typeForIntersection(resolver, [d.pattern0, d.pattern1, ... d.patternN]);
case 'Pattern':
return typeFor(resolver, d.value);
}
}
export function typeForIntersection(resolver: RefResolver, ps: M.NamedPattern[]): SimpleType {
const fs = new Map();
ps.forEach(p => gatherFields(fs, resolver, p));
return fs.size > 0 ? Type.record(fs) : Type.unit();
}
export function typeFor(resolver: RefResolver, p: M.Pattern): SimpleType {
if (p._variant === 'SimplePattern') {
return simpleType(resolver, p.value);
} else {
return typeForIntersection(resolver, [M.NamedPattern.anonymous(p)]);
}
}
export function simpleType(resolver: RefResolver, p: M.SimplePattern): FieldType {
switch (p._variant) {
case 'any':
return ANY_TYPE;
case 'atom':
switch (p.atomKind._variant) {
case 'Boolean': return Type.ref(`boolean`);
case 'Float': return Type.ref(`number`);
case 'Double': return Type.ref(`number`);
case 'SignedInteger': return Type.ref(`number`);
case 'String': return Type.ref(`string`);
case 'ByteString': return Type.ref(`_.Bytes`);
case 'Symbol': return Type.ref(`symbol`);
}
case 'embedded':
return Type.ref(`_embedded`);
case 'lit':
return Type.unit();
case 'seqof':
return Type.array(simpleType(resolver, p.pattern));
case 'setof':
return Type.set(simpleType(resolver, p.pattern));
case 'dictof':
return Type.dictionary(simpleType(resolver, p.key), simpleType(resolver, p.value));
case 'Ref':
return resolver(p.value);
default:
((_p: never) => {})(p);
throw new Error("Unreachable");
}
}
function compoundFields(fs: FieldMap, resolver: RefResolver, p: M.CompoundPattern): void {
switch (p._variant) {
case 'rec':
gatherFields(fs, resolver, p.label);
gatherFields(fs, resolver, p.fields);
break;
case 'tuple':
p.patterns.forEach(pp => gatherFields(fs, resolver, pp));
break;
case 'tuple*':
p.fixed.forEach(pp => gatherFields(fs, resolver, pp));
gatherFields(fs, resolver, M.promoteNamedSimplePattern(p.variable));
break;
case 'dict':
p.entries.forEach((n, _k) =>
gatherFields(fs, resolver, M.promoteNamedSimplePattern(n)));
break;
default:
((_p: never) => {})(p);
throw new Error("Unreachable");
}
}
function gatherFields(fs: FieldMap, resolver: RefResolver, n: M.NamedPattern): void {
if (n._variant === 'named') {
const t = simpleType(resolver, n.value.pattern);
if (t.kind !== 'unit') {
fs.set(n.value.name.description!, t);
}
} else if (n.value._variant === 'CompoundPattern') {
compoundFields(fs, resolver, n.value.value);
}
}