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uzu: stacks now work within () + write more tests

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This commit is contained in:
Felix Roos 2025-03-16 00:51:59 +01:00
parent dbe3915368
commit b71b1354c3
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2 changed files with 41 additions and 13 deletions
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31
packages/uzu/uzu.mjs
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@ -86,10 +86,14 @@ export class UzuParser {
return children;
}
// Token[] => Token[][] . returns empty list if type not found
split_children(children, type) {
split_children(children, split_type, sequence_type) {
if (sequence_type) {
// if given, the first child is ignored
children = children.slice(1);
}
const chunks = [];
while (true) {
let commaIndex = children.findIndex((child) => child.type === type);
let commaIndex = children.findIndex((child) => child.type === split_type);
if (commaIndex === -1) break;
const chunk = children.slice(0, commaIndex);
chunks.push(chunk);
@ -101,13 +105,11 @@ export class UzuParser {
chunks.push(children);
return chunks;
}
desugar_stack(children) {
let [type, ...rest] = children;
desugar_stack(children, sequence_type) {
// children is expected to contain seq or cat as first item
const chunks = this.split_children(rest, 'stack');
const chunks = this.split_children(children, 'stack', sequence_type);
if (!chunks.length) {
// no stack
return children;
return this.desugar_children(children);
}
// collect args of stack function
const args = chunks.map((chunk) => {
@ -115,8 +117,14 @@ export class UzuParser {
// chunks of one element can be added to the stack as is
return chunk[0];
} else {
// chunks of multiple args are added to a subsequence of type
return { type: 'list', children: [type, ...chunk] };
// chunks of multiple args
if (sequence_type) {
// if given, each chunk needs to be prefixed
// [a b, c d] => (stack (seq a b) (seq c d))
chunk = [{ type: 'plain', value: sequence_type }, ...chunk];
}
chunk = this.desugar_children(chunk);
return { type: 'list', children: chunk };
}
});
return [{ type: 'plain', value: 'stack' }, ...args];
@ -203,21 +211,22 @@ export class UzuParser {
}
parse_list() {
let children = this.parse_pair('open_list', 'close_list');
children = this.desugar_stack(children);
children = this.desugar_children(children);
return { type: 'list', children };
}
parse_cat() {
let children = this.parse_pair('open_cat', 'close_cat');
children = [{ type: 'plain', value: 'cat' }, ...children];
children = this.desugar_children(children);
children = this.desugar_stack(children, 'cat');
children = this.desugar_children(children);
return { type: 'list', children };
}
parse_seq() {
let children = this.parse_pair('open_seq', 'close_seq');
children = [{ type: 'plain', value: 'seq' }, ...children];
children = this.desugar_children(children);
children = this.desugar_stack(children, 'seq');
children = this.desugar_children(children);
return { type: 'list', children };
}
consume(type) {