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

129 lines
4.6 KiB
TypeScript

import { refPosition } from "../reader";
import * as M from "../meta";
import { ModuleContext } from "./context";
import { ANY_TYPE, AtomicType, CollectionType, FieldMap, SimpleType, Type } from "./type";
export function typeForDefinition(mod: ModuleContext, d: M.Definition): Type {
if (d._variant === 'or') {
return Type.union(
new Map([d.pattern, ... d.patterns].map(a =>
[a.variantLabel, typeForAlternative(mod, a.alternative)])));
} else {
return typeForAlternative(mod, d.value);
}
}
export function typeForAlternative(mod: ModuleContext, a: M.Alternative): SimpleType {
if (a._variant === 'and') {
const fs = new Map();
gatherFields(fs, mod, a.pattern);
a.patterns.forEach(n => gatherFields(fs, mod, n));
return fs.size > 0 ? Type.record(fs) : Type.unit();
} else {
return typeFor(mod, a.value);
}
}
export function setType(mod: ModuleContext, p: M.SimplePattern): CollectionType {
return Type.set(simpleType(mod, p));
}
export function dictionaryType(mod: ModuleContext,
kp: M.SimplePattern,
vp: M.SimplePattern): CollectionType
{
return Type.dictionary(simpleType(mod, kp), simpleType(mod, vp));
}
export function typeFor(mod: ModuleContext, p: M.Pattern): SimpleType {
if (p._variant === 'SimplePattern') {
return simpleType(mod, p.value);
} else {
switch (p.value._variant) {
case 'setof':
return setType(mod, p.value.pattern);
case 'dictof':
return dictionaryType(mod, p.value.key, p.value.value);
default: {
const arrayType = M.simpleArray(p.value);
if (arrayType === void 0) {
const fs = new Map();
compoundFields(fs, mod, p.value);
return fs.size > 0 ? Type.record(fs) : Type.unit();
} else {
return Type.array(simpleType(mod, arrayType));
}
}
}
}
}
export function simpleType(mod: ModuleContext, p: M.SimplePattern): AtomicType {
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 'Ref':
return M.lookup(refPosition(p.value), p.value, mod.env,
(_p) => Type.ref(p.value.name.description!),
(modId, modPath,_p) => {
mod.imports.add([modId, modPath]);
return Type.ref(`${modId}.${p.value.name.description!}`);
});
default:
((_p: never) => {})(p);
throw new Error("Unreachable");
}
}
function compoundFields(fs: FieldMap, mod: ModuleContext, p: M.CompoundPattern): void {
switch (p._variant) {
case 'rec':
gatherFields(fs, mod, p.label);
gatherFields(fs, mod, p.fields);
break;
case 'tuple':
p.patterns.forEach(pp => gatherFields(fs, mod, pp));
break;
case 'tuple*': {
p.fixed.forEach(pp => gatherFields(fs, mod, pp));
const n = p.variable;
if (n._variant === 'named') {
fs.set(n.value.name.description!, Type.array(simpleType(mod, n.value.pattern)));
}
break;
}
case 'setof':
case 'dictof':
break;
case 'dict':
p.entries.forEach((n, k) =>
gatherFields(fs, mod, M.promoteNamedSimplePattern(M.addNameIfAbsent(n, k))));
break;
default:
((_p: never) => {})(p);
throw new Error("Unreachable");
}
}
function gatherFields(fs: FieldMap, mod: ModuleContext, n: M.NamedPattern): void {
if (n._variant === 'named') {
fs.set(n.value.name.description!, simpleType(mod, n.value.pattern));
} else if (n.value._variant === 'CompoundPattern') {
compoundFields(fs, mod, n.value.value);
}
}