Files
plainleaf/client/space_lua/stdlib/string.ts
T

377 lines
12 KiB
TypeScript

import {
jsToLuaValue,
LuaBuiltinFunction,
LuaMultiRes,
LuaRuntimeError,
LuaTable,
luaToString,
} from "../runtime.ts";
import { isTaggedFloat, untagNumber } from "../numeric.ts";
import { luaFormat } from "./format.ts";
import {
type CaptureResult,
type GsubCallbacks,
patternFind,
patternGmatch,
patternGsub,
patternMatch,
} from "./pattern.ts";
import { strPackFn, strPackSizeFn, strUnpackFn } from "./string_pack.ts";
function capturesToLua(caps: CaptureResult[]): any {
if (caps.length === 0) return null;
if (caps.length === 1) {
const c = caps[0];
return "s" in c ? c.s : c.position;
}
return new LuaMultiRes(caps.map((c) => ("s" in c ? c.s : c.position)));
}
export const stringApi = new LuaTable({
byte: new LuaBuiltinFunction({
callback: (_sf, s: string, i?: number, j?: number) => {
i = i ?? 1;
j = j ?? i;
if (j > s.length) j = s.length;
if (i < 1) i = 1;
const result = [];
for (let k = i; k <= j; k++) {
result.push(s.charCodeAt(k - 1));
}
return new LuaMultiRes(result);
},
description:
"Returns the numeric character codes in the inclusive range from `i` to `j`.",
parameters: [
{ name: "s", type: "string" },
{ name: "i", type: "integer", optional: true },
{ name: "j", type: "integer", optional: true },
],
returns: [{ type: "integer", description: "One result per character." }],
}),
char: new LuaBuiltinFunction({
callback: (_sf, ...args: number[]) => String.fromCharCode(...args),
description: "Creates a string from numeric character codes.",
signatures: ["string.char(...): string"],
returns: [{ type: "string" }],
}),
find: new LuaBuiltinFunction({
callback: (_sf, s: string, pattern: string, init = 1, plain = false) => {
const r = patternFind(s, pattern, init, plain);
if (!r) return null;
const result: any[] = [r.start, r.end];
for (const c of r.captures) {
result.push("s" in c ? c.s : c.position);
}
return new LuaMultiRes(result);
},
description:
"Finds the first Lua-pattern match and returns its bounds followed by captures.",
parameters: [
{ name: "s", type: "string" },
{ name: "pattern", type: "string" },
{ name: "init", type: "integer", optional: true },
{ name: "plain", type: "boolean", optional: true },
],
returns: [
{ type: "integer|nil", description: "Start index or `nil`." },
{ type: "integer", description: "End index." },
],
}),
format: new LuaBuiltinFunction({
callback: (_sf, format: string, ...args: any[]) => {
for (let i = 0; i < args.length; i++) {
args[i] = untagNumber(args[i]);
}
return luaFormat(format, ...args);
},
description: "Formats values according to a C-style format string.",
signatures: ["string.format(format, ...): string"],
parameters: [
{ name: "format", type: "string" },
{
name: "...",
description: "Values consumed by conversion specifiers.",
},
],
returns: [{ type: "string" }],
examples: [
{ code: 'print(string.format("Name: %s, score: %.1f", "Ada", 9.5))' },
],
}),
gmatch: new LuaBuiltinFunction({
callback: (_sf, s: string, pattern: string, init = 1) => {
const iter = patternGmatch(s, pattern, init);
return () => {
const caps = iter();
if (!caps) return;
return capturesToLua(caps);
};
},
description:
"Returns an iterator over successive Lua-pattern matches and captures.",
parameters: [
{ name: "s", type: "string" },
{ name: "pattern", type: "string" },
{ name: "init", type: "integer", optional: true },
],
returns: [{ type: "function", description: "Match iterator." }],
examples: [
{
code: 'for word in string.gmatch("hello world", "%w+") do\n print(word)\nend',
},
],
}),
gsub: new LuaBuiltinFunction({
callback: async (sf, s: string, pattern: string, repl: any, n?: number) => {
const callbacks: GsubCallbacks = {};
if (typeof repl === "string") {
callbacks.replString = repl;
} else if (repl instanceof LuaTable) {
callbacks.replTable = (key: string) => {
const v = repl.get(key);
if (v === null || v === undefined || v === false) return null;
return typeof v === "number"
? String(v)
: String(isTaggedFloat(v) ? v.value : v);
};
} else if (repl.call) {
callbacks.replFunction = async (...caps: CaptureResult[]) => {
const args = caps.map((c) => ("s" in c ? c.s : c.position));
let result = await repl.call(sf, ...args);
if (result instanceof LuaMultiRes) {
result = result.values[0];
}
if (result === null || result === undefined || result === false) {
return null;
}
return luaToString(result);
};
} else {
throw new LuaRuntimeError(
"string.gsub replacement argument should be a function, table or string",
sf,
);
}
const [result, count] = await patternGsub(s, pattern, callbacks, n);
return new LuaMultiRes([result, count]);
},
description:
"Replaces Lua-pattern matches using a string, table, or function replacement.",
parameters: [
{ name: "s", type: "string" },
{ name: "pattern", type: "string" },
{ name: "replacement", type: "string|table|function" },
{ name: "n", type: "integer", optional: true },
],
returns: [
{ type: "string", description: "Result string." },
{ type: "integer", description: "Number of replacements." },
],
examples: [
{
code: 'local result, count = string.gsub("hello hello", "hello", "hi", 1)\nprint(result, count) -- hi hello 1',
},
],
}),
len: new LuaBuiltinFunction({
callback: (_sf, s: string) => s.length,
description: "Returns the length of a string.",
parameters: [{ name: "s", type: "string" }],
returns: [{ type: "integer" }],
}),
lower: new LuaBuiltinFunction({
callback: (_sf, s: string) => luaToString(s.toLowerCase()),
description: "Returns a copy of a string converted to lowercase.",
parameters: [{ name: "s", type: "string" }],
returns: [{ type: "string" }],
}),
upper: new LuaBuiltinFunction({
callback: (_sf, s: string) => luaToString(s.toUpperCase()),
description: "Returns a copy of a string converted to uppercase.",
parameters: [{ name: "s", type: "string" }],
returns: [{ type: "string" }],
}),
match: new LuaBuiltinFunction({
callback: (_sf, s: string, pattern: string, init = 1) => {
const caps = patternMatch(s, pattern, init);
if (!caps) return null;
return capturesToLua(caps);
},
description:
"Returns captures from the first Lua-pattern match, or `nil` when none is found.",
parameters: [
{ name: "s", type: "string" },
{ name: "pattern", type: "string" },
{ name: "init", type: "integer", optional: true },
],
returns: [{ description: "Pattern captures, whole match, or `nil`." }],
examples: [
{ code: 'local year, month = string.match("2024-03", "(%d+)%-(%d+)")' },
],
}),
rep: new LuaBuiltinFunction({
callback: (_sf, s: string, n: number, sep?: string) => {
if (n <= 0) return "";
sep = sep ?? "";
const parts: string[] = [];
for (let i = 0; i < n; i++) {
parts.push(s);
}
return parts.join(sep);
},
description:
"Returns `n` copies of a string joined by an optional separator.",
parameters: [
{ name: "s", type: "string" },
{ name: "n", type: "integer" },
{ name: "sep", type: "string", optional: true },
],
returns: [{ type: "string" }],
}),
reverse: new LuaBuiltinFunction({
callback: (_sf, s: string) => s.split("").reverse().join(""),
description: "Returns a string with its characters in reverse order.",
parameters: [{ name: "s", type: "string" }],
returns: [{ type: "string" }],
}),
sub: new LuaBuiltinFunction({
callback: (_sf, s: string, i: number, j?: number) => {
const len = s.length;
let start: number;
if (i > 0) {
start = i;
} else if (i < -len) {
start = 1;
} else {
start = i === 0 ? 1 : len + i + 1;
}
let end: number;
if (j === undefined || j === null || j > len) {
end = len;
} else if (j >= 0) {
end = j;
} else if (j < -len) {
end = 0;
} else {
end = len + j + 1;
}
if (start <= end) {
return s.substring(start - 1, end);
}
return "";
},
description:
"Returns the substring from inclusive index `i` through `j`, supporting negative indices.",
parameters: [
{ name: "s", type: "string" },
{ name: "i", type: "integer" },
{ name: "j", type: "integer", optional: true },
],
returns: [{ type: "string" }],
}),
split: new LuaBuiltinFunction({
callback: (_sf, s: string, sep: string) => s.split(sep),
description:
"Splits a string on a literal separator and returns the substrings.",
parameters: [
{ name: "s", type: "string" },
{ name: "sep", type: "string" },
],
returns: [{ type: "table" }],
examples: [
{
code: 'for part in each(string.split("a,b,c", ",")) do\n print(part)\nend',
},
],
}),
pack: strPackFn,
unpack: strUnpackFn,
packsize: strPackSizeFn,
// Non-standard extensions
startsWith: new LuaBuiltinFunction({
callback: (_sf, s: string, prefix: string) => s.startsWith(prefix),
description: "Returns whether a string starts with a literal prefix.",
parameters: [
{ name: "s", type: "string" },
{ name: "prefix", type: "string" },
],
returns: [{ type: "boolean" }],
}),
endsWith: new LuaBuiltinFunction({
callback: (_sf, s: string, suffix: string) => s.endsWith(suffix),
description: "Returns whether a string ends with a literal suffix.",
parameters: [
{ name: "s", type: "string" },
{ name: "suffix", type: "string" },
],
returns: [{ type: "boolean" }],
}),
trim: new LuaBuiltinFunction({
callback: (_sf, s: string) => s.trim(),
description: "Removes whitespace from both ends of a string.",
parameters: [{ name: "s", type: "string" }],
returns: [{ type: "string" }],
}),
trimStart: new LuaBuiltinFunction({
callback: (_sf, s: string) => s.trimStart(),
description: "Removes whitespace from the beginning of a string.",
parameters: [{ name: "s", type: "string" }],
returns: [{ type: "string" }],
}),
trimEnd: new LuaBuiltinFunction({
callback: (_sf, s: string) => s.trimEnd(),
description: "Removes whitespace from the end of a string.",
parameters: [{ name: "s", type: "string" }],
returns: [{ type: "string" }],
}),
matchRegex: new LuaBuiltinFunction({
callback: (_sf, s: string, pattern: string) => {
const regex = new RegExp(pattern);
const result = s.match(regex);
return jsToLuaValue(result);
},
description:
"Matches a string with a JavaScript regular expression and returns the match array.",
parameters: [
{ name: "s", type: "string" },
{ name: "pattern", type: "string" },
],
returns: [{ type: "table|nil" }],
examples: [
{
code: 'local match = string.matchRegex("hello123", "([a-z]+)([0-9]+)")\nprint(match[1], match[2], match[3])',
},
],
}),
matchRegexAll: new LuaBuiltinFunction({
callback: (_sf, s: string, pattern: string) => {
const regex = new RegExp(pattern, "g");
return () => {
const match = regex.exec(s);
if (!match) {
return;
}
return jsToLuaValue(match);
};
},
description:
"Returns an iterator over all JavaScript regular-expression matches.",
parameters: [
{ name: "s", type: "string" },
{ name: "pattern", type: "string" },
],
returns: [
{ type: "function", description: "Iterator yielding match arrays." },
],
examples: [
{
code: 'for match in string.matchRegexAll("a1b2", "([a-z])([0-9])") do\n print(match[1], match[2], match[3])\nend',
},
],
}),
});