418 lines
9.8 KiB
JavaScript
418 lines
9.8 KiB
JavaScript
function alias(rule, value) {
|
|
const result = {
|
|
type: "ALIAS",
|
|
content: normalize(rule),
|
|
named: false,
|
|
value: null
|
|
};
|
|
|
|
switch (value.constructor) {
|
|
case String:
|
|
result.named = false;
|
|
result.value = value;
|
|
return result;
|
|
case ReferenceError:
|
|
result.named = true;
|
|
result.value = value.symbol.name;
|
|
return result;
|
|
case Object:
|
|
if (typeof value.type === 'string' && value.type === 'SYMBOL') {
|
|
result.named = true;
|
|
result.value = value.name;
|
|
return result;
|
|
}
|
|
}
|
|
|
|
throw new Error('Invalid alias value ' + value);
|
|
}
|
|
|
|
function blank() {
|
|
return {
|
|
type: "BLANK"
|
|
};
|
|
}
|
|
|
|
function field(name, rule) {
|
|
return {
|
|
type: "FIELD",
|
|
name: name,
|
|
content: normalize(rule)
|
|
}
|
|
}
|
|
|
|
function choice(...elements) {
|
|
return {
|
|
type: "CHOICE",
|
|
members: elements.map(normalize)
|
|
};
|
|
}
|
|
|
|
function optional(value) {
|
|
checkArguments(arguments.length, optional, 'optional');
|
|
return choice(value, blank());
|
|
}
|
|
|
|
function prec(number, rule) {
|
|
checkPrecedence(number);
|
|
checkArguments(
|
|
arguments.length - 1,
|
|
prec,
|
|
'prec',
|
|
' and a precedence argument'
|
|
);
|
|
|
|
return {
|
|
type: "PREC",
|
|
value: number,
|
|
content: normalize(rule)
|
|
};
|
|
}
|
|
|
|
prec.left = function(number, rule) {
|
|
if (rule == null) {
|
|
rule = number;
|
|
number = 0;
|
|
}
|
|
|
|
checkPrecedence(number);
|
|
checkArguments(
|
|
arguments.length - 1,
|
|
prec.left,
|
|
'prec.left',
|
|
' and an optional precedence argument'
|
|
);
|
|
|
|
return {
|
|
type: "PREC_LEFT",
|
|
value: number,
|
|
content: normalize(rule)
|
|
};
|
|
}
|
|
|
|
prec.right = function(number, rule) {
|
|
if (rule == null) {
|
|
rule = number;
|
|
number = 0;
|
|
}
|
|
|
|
checkPrecedence(number);
|
|
checkArguments(
|
|
arguments.length - 1,
|
|
prec.right,
|
|
'prec.right',
|
|
' and an optional precedence argument'
|
|
);
|
|
|
|
return {
|
|
type: "PREC_RIGHT",
|
|
value: number,
|
|
content: normalize(rule)
|
|
};
|
|
}
|
|
|
|
prec.dynamic = function(number, rule) {
|
|
checkPrecedence(number);
|
|
checkArguments(
|
|
arguments.length - 1,
|
|
prec.dynamic,
|
|
'prec.dynamic',
|
|
' and a precedence argument'
|
|
);
|
|
|
|
return {
|
|
type: "PREC_DYNAMIC",
|
|
value: number,
|
|
content: normalize(rule)
|
|
};
|
|
}
|
|
|
|
function repeat(rule) {
|
|
checkArguments(arguments.length, repeat, 'repeat');
|
|
return {
|
|
type: "REPEAT",
|
|
content: normalize(rule)
|
|
};
|
|
}
|
|
|
|
function repeat1(rule) {
|
|
checkArguments(arguments.length, repeat1, 'repeat1');
|
|
return {
|
|
type: "REPEAT1",
|
|
content: normalize(rule)
|
|
};
|
|
}
|
|
|
|
function seq(...elements) {
|
|
return {
|
|
type: "SEQ",
|
|
members: elements.map(normalize)
|
|
};
|
|
}
|
|
|
|
function sym(name) {
|
|
return {
|
|
type: "SYMBOL",
|
|
name: name
|
|
};
|
|
}
|
|
|
|
function token(value) {
|
|
return {
|
|
type: "TOKEN",
|
|
content: normalize(value)
|
|
};
|
|
}
|
|
|
|
token.immediate = function(value) {
|
|
return {
|
|
type: "IMMEDIATE_TOKEN",
|
|
content: normalize(value)
|
|
};
|
|
}
|
|
|
|
function normalize(value) {
|
|
if (typeof value == "undefined")
|
|
throw new Error("Undefined symbol");
|
|
|
|
switch (value.constructor) {
|
|
case String:
|
|
return {
|
|
type: 'STRING',
|
|
value
|
|
};
|
|
case RegExp:
|
|
return {
|
|
type: 'PATTERN',
|
|
value: value.source
|
|
};
|
|
case ReferenceError:
|
|
throw value
|
|
default:
|
|
if (typeof value.type === 'string') {
|
|
return value;
|
|
} else {
|
|
throw new TypeError("Invalid rule: " + value.toString());
|
|
}
|
|
}
|
|
}
|
|
|
|
function RuleBuilder(ruleMap) {
|
|
return new Proxy({}, {
|
|
get(target, propertyName) {
|
|
const symbol = sym(propertyName);
|
|
|
|
if (!ruleMap || ruleMap.hasOwnProperty(propertyName)) {
|
|
return symbol;
|
|
} else {
|
|
const error = new ReferenceError(`Undefined symbol '${propertyName}'`);
|
|
error.symbol = symbol;
|
|
return error;
|
|
}
|
|
}
|
|
})
|
|
}
|
|
|
|
function grammar(baseGrammar, options) {
|
|
if (!options) {
|
|
options = baseGrammar;
|
|
baseGrammar = {
|
|
name: null,
|
|
rules: {},
|
|
extras: [normalize(/\s/)],
|
|
conflicts: [],
|
|
externals: [],
|
|
inline: [],
|
|
supertypes: [],
|
|
precedences: [],
|
|
};
|
|
}
|
|
|
|
let externals = baseGrammar.externals;
|
|
if (options.externals) {
|
|
if (typeof options.externals !== "function") {
|
|
throw new Error("Grammar's 'externals' property must be a function.");
|
|
}
|
|
|
|
const externalsRuleBuilder = RuleBuilder(null)
|
|
const externalRules = options.externals.call(externalsRuleBuilder, externalsRuleBuilder, baseGrammar.externals);
|
|
|
|
if (!Array.isArray(externalRules)) {
|
|
throw new Error("Grammar's 'externals' property must return an array of rules.");
|
|
}
|
|
|
|
externals = externalRules.map(normalize);
|
|
}
|
|
|
|
const ruleMap = {};
|
|
for (const key in options.rules) {
|
|
ruleMap[key] = true;
|
|
}
|
|
for (const key in baseGrammar.rules) {
|
|
ruleMap[key] = true;
|
|
}
|
|
for (const external of externals) {
|
|
if (typeof external.name === 'string') {
|
|
ruleMap[external.name] = true;
|
|
}
|
|
}
|
|
|
|
const ruleBuilder = RuleBuilder(ruleMap);
|
|
|
|
const name = options.name;
|
|
if (typeof name !== "string") {
|
|
throw new Error("Grammar's 'name' property must be a string.");
|
|
}
|
|
|
|
if (!/^[a-zA-Z_]\w*$/.test(name)) {
|
|
throw new Error("Grammar's 'name' property must not start with a digit and cannot contain non-word characters.");
|
|
}
|
|
|
|
let rules = Object.assign({}, baseGrammar.rules);
|
|
if (options.rules) {
|
|
if (typeof options.rules !== "object") {
|
|
throw new Error("Grammar's 'rules' property must be an object.");
|
|
}
|
|
|
|
for (const ruleName in options.rules) {
|
|
const ruleFn = options.rules[ruleName];
|
|
if (typeof ruleFn !== "function") {
|
|
throw new Error("Grammar rules must all be functions. '" + ruleName + "' rule is not.");
|
|
}
|
|
rules[ruleName] = normalize(ruleFn.call(ruleBuilder, ruleBuilder, baseGrammar.rules[ruleName]));
|
|
}
|
|
}
|
|
|
|
let extras = baseGrammar.extras.slice();
|
|
if (options.extras) {
|
|
if (typeof options.extras !== "function") {
|
|
throw new Error("Grammar's 'extras' property must be a function.");
|
|
}
|
|
|
|
extras = options.extras
|
|
.call(ruleBuilder, ruleBuilder, baseGrammar.extras)
|
|
|
|
if (!Array.isArray(extras)) {
|
|
throw new Error("Grammar's 'extras' function must return an array.")
|
|
}
|
|
|
|
extras = extras.map(normalize);
|
|
}
|
|
|
|
let word = baseGrammar.word;
|
|
if (options.word) {
|
|
word = options.word.call(ruleBuilder, ruleBuilder).name;
|
|
if (typeof word != 'string') {
|
|
throw new Error("Grammar's 'word' property must be a named rule.");
|
|
}
|
|
}
|
|
|
|
let conflicts = baseGrammar.conflicts;
|
|
if (options.conflicts) {
|
|
if (typeof options.conflicts !== "function") {
|
|
throw new Error("Grammar's 'conflicts' property must be a function.");
|
|
}
|
|
|
|
const baseConflictRules = baseGrammar.conflicts.map(conflict => conflict.map(sym));
|
|
const conflictRules = options.conflicts.call(ruleBuilder, ruleBuilder, baseConflictRules);
|
|
|
|
if (!Array.isArray(conflictRules)) {
|
|
throw new Error("Grammar's conflicts must be an array of arrays of rules.");
|
|
}
|
|
|
|
conflicts = conflictRules.map(conflictSet => {
|
|
if (!Array.isArray(conflictSet)) {
|
|
throw new Error("Grammar's conflicts must be an array of arrays of rules.");
|
|
}
|
|
|
|
return conflictSet.map(symbol => normalize(symbol).name);
|
|
});
|
|
}
|
|
|
|
let inline = baseGrammar.inline;
|
|
if (options.inline) {
|
|
if (typeof options.inline !== "function") {
|
|
throw new Error("Grammar's 'inline' property must be a function.");
|
|
}
|
|
|
|
const baseInlineRules = baseGrammar.inline.map(sym);
|
|
const inlineRules = options.inline.call(ruleBuilder, ruleBuilder, baseInlineRules);
|
|
|
|
if (!Array.isArray(inlineRules)) {
|
|
throw new Error("Grammar's inline must be an array of rules.");
|
|
}
|
|
|
|
inline = inlineRules.map(symbol => symbol.name);
|
|
}
|
|
|
|
let supertypes = baseGrammar.supertypes;
|
|
if (options.supertypes) {
|
|
if (typeof options.supertypes !== "function") {
|
|
throw new Error("Grammar's 'supertypes' property must be a function.");
|
|
}
|
|
|
|
const baseSupertypeRules = baseGrammar.supertypes.map(sym);
|
|
const supertypeRules = options.supertypes.call(ruleBuilder, ruleBuilder, baseSupertypeRules);
|
|
|
|
if (!Array.isArray(supertypeRules)) {
|
|
throw new Error("Grammar's supertypes must be an array of rules.");
|
|
}
|
|
|
|
supertypes = supertypeRules.map(symbol => symbol.name);
|
|
}
|
|
|
|
let precedences = baseGrammar.precedences;
|
|
if (options.precedences) {
|
|
if (typeof options.precedences !== "function") {
|
|
throw new Error("Grammar's 'precedences' property must be a function");
|
|
}
|
|
precedences = options.precedences.call(ruleBuilder, ruleBuilder, baseGrammar.precedences);
|
|
if (!Array.isArray(precedences)) {
|
|
throw new Error("Grammar's precedences must be an array of arrays of rules.");
|
|
}
|
|
precedences = precedences.map(list => {
|
|
if (!Array.isArray(list)) {
|
|
throw new Error("Grammar's precedences must be an array of arrays of rules.");
|
|
}
|
|
return list.map(normalize);
|
|
});
|
|
}
|
|
|
|
if (Object.keys(rules).length == 0) {
|
|
throw new Error("Grammar must have at least one rule.");
|
|
}
|
|
|
|
return {name, word, rules, extras, conflicts, precedences, externals, inline, supertypes};
|
|
}
|
|
|
|
function checkArguments(ruleCount, caller, callerName, suffix = '') {
|
|
if (ruleCount > 1) {
|
|
const error = new Error([
|
|
`The \`${callerName}\` function only takes one rule argument${suffix}.`,
|
|
'You passed multiple rules. Did you mean to call `seq`?\n'
|
|
].join('\n'));
|
|
Error.captureStackTrace(error, caller);
|
|
throw error
|
|
}
|
|
}
|
|
|
|
function checkPrecedence(value) {
|
|
if (value == null) {
|
|
throw new Error('Missing precedence value');
|
|
}
|
|
}
|
|
|
|
global.alias = alias;
|
|
global.blank = blank;
|
|
global.choice = choice;
|
|
global.optional = optional;
|
|
global.prec = prec;
|
|
global.repeat = repeat;
|
|
global.repeat1 = repeat1;
|
|
global.seq = seq;
|
|
global.sym = sym;
|
|
global.token = token;
|
|
global.grammar = grammar;
|
|
global.field = field;
|
|
|
|
const result = require(process.env.TREE_SITTER_GRAMMAR_PATH);
|
|
console.log(JSON.stringify(result, null, 2));
|