Delete: Decompose into src/lexer, src/parser, src/ast-builder

This commit is contained in:
2025-09-26 08:21:18 -07:00
parent eba1bce8c1
commit 660a45fafa

281
parser.js
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@@ -1,281 +0,0 @@
import { CstParser, Lexer, createToken } from 'chevrotain';
// 1. Lexer Definition
// -------------------
const tokens = {};
const tokenList = [
createToken({ name: 'WhiteSpace', pattern: /[ \t]+/, group: Lexer.SKIPPED }),
createToken({ name: 'NewLine', pattern: /\n|\r\n?/, group: Lexer.SKIPPED }),
createToken({ name: 'Comment', pattern: /\/\/[^\n\r]*/, group: Lexer.SKIPPED }),
createToken({ name: 'Number', pattern: /0|[1-9][0-9]*(\.[0-9]+)?/ }),
createToken({ name: 'String', pattern: /"(?:\\["\\]|[^\n"\\])*"/ }),
createToken({ name: 'LBrace', pattern: /{/ }),
createToken({ name: 'RBrace', pattern: /}/ }),
createToken({ name: 'LParen', pattern: /\(/ }),
createToken({ name: 'RParen', pattern: /\)/ }),
createToken({ name: 'Dot', pattern: /\./ }),
createToken({ name: 'Plus', pattern: /\+/ }),
createToken({ name: 'Comma', pattern: /,/ }),
createToken({ name: 'Colon', pattern: /:/ }),
createToken({ name: 'Eq', pattern: /=/ }),
createToken({ name: 'Identifier', pattern: /[a-zA-Z_][a-zA-Z0-9_]*/ }),
];
tokenList.forEach(tokenType => {
tokens[tokenType.name] = tokenType;
});
export const HiLexer = new Lexer(tokenList);
// 2. Parser Definition
// --------------------
class HiParser extends CstParser {
constructor() {
super(tokenList);
const $ = this;
$.RULE('program', () => {
$.SUBRULE($.statements);
});
$.RULE('statements', () => {
$.MANY(() => {
$.SUBRULE($.statement);
});
});
$.RULE('statement', () => {
$.OR([
{ ALT: () => $.SUBRULE($.declaration) },
{ ALT: () => $.SUBRULE($.assignment) },
{ ALT: () => $.SUBRULE($.expressionStatement) },
]);
});
$.RULE('expressionStatement', () => {
$.SUBRULE($.expression);
});
$.RULE('declaration', () => {
$.CONSUME(tokens.Identifier);
$.CONSUME(tokens.Colon);
$.SUBRULE($.expression);
});
$.RULE('assignment', () => {
$.CONSUME(tokens.Identifier);
$.CONSUME(tokens.Eq);
$.SUBRULE($.expression);
});
$.RULE('expression', () => {
$.SUBRULE($.additiveExpression);
});
$.RULE('additiveExpression', () => {
$.SUBRULE($.callExpression, { LABEL: 'left' });
$.MANY(() => {
$.CONSUME(tokens.Plus);
$.SUBRULE2($.callExpression, { LABEL: 'right' });
});
});
$.RULE('callExpression', () => {
$.SUBRULE($.memberExpression);
$.OPTION(() => {
$.CONSUME(tokens.LParen);
$.OPTION2(() => $.SUBRULE($.argumentList));
$.CONSUME(tokens.RParen);
});
});
$.RULE('argumentList', () => {
$.SUBRULE($.expression);
$.MANY(() => {
$.CONSUME(tokens.Comma);
$.SUBRULE2($.expression);
});
});
$.RULE('memberExpression', () => {
$.SUBRULE($.primary);
$.MANY(() => {
$.CONSUME(tokens.Dot);
$.CONSUME(tokens.Identifier);
});
});
$.RULE('primary', () => {
$.OR([
{ ALT: () => $.SUBRULE($.literal) },
{ ALT: () => $.CONSUME(tokens.Identifier) },
{ ALT: () => $.SUBRULE($.block) },
{ ALT: () => {
$.CONSUME(tokens.LParen);
$.SUBRULE($.expression);
$.CONSUME(tokens.RParen);
}}
]);
});
$.RULE('literal', () => {
$.OR([
{ ALT: () => $.CONSUME(tokens.Number) },
{ ALT: () => $.CONSUME(tokens.String) },
]);
});
$.RULE('block', () => {
$.CONSUME(tokens.LBrace);
$.OPTION(() => {
$.SUBRULE($.keyValuePairs);
});
$.CONSUME(tokens.RBrace);
});
$.RULE('keyValuePairs', () => {
$.AT_LEAST_ONE(() => $.SUBRULE($.keyValuePair));
});
$.RULE('keyValuePair', () => {
$.CONSUME(tokens.Identifier);
$.CONSUME(tokens.Colon);
$.SUBRULE($.expression);
});
this.performSelfAnalysis();
}
}
export const parser = new HiParser();
// 3. AST Builder (CST Visitor)
// ----------------------------
const BaseHiVisitor = parser.getBaseCstVisitorConstructor();
class AstBuilder extends BaseHiVisitor {
constructor() {
super();
this.validateVisitor();
}
// Entry rule
program(ctx) {
return { type: 'Program', body: this.visit(ctx.statements) };
}
statements(ctx) {
return ctx.statement?.map(stmt => this.visit(stmt)) || [];
}
statement(ctx) {
if (ctx.declaration) return this.visit(ctx.declaration);
if (ctx.assignment) return this.visit(ctx.assignment);
if (ctx.expressionStatement) return this.visit(ctx.expressionStatement);
}
expressionStatement(ctx) {
return { type: 'ExpressionStatement', expression: this.visit(ctx.expression) };
}
declaration(ctx) {
return {
type: 'VariableDeclaration',
identifier: ctx.Identifier[0].image,
value: this.visit(ctx.expression),
};
}
assignment(ctx) {
return {
type: 'Assignment',
identifier: ctx.Identifier[0].image,
value: this.visit(ctx.expression),
};
}
expression(ctx) {
return this.visit(ctx.additiveExpression);
}
additiveExpression(ctx) {
let left = this.visit(ctx.left);
if (ctx.right) {
ctx.right.forEach((rhs, i) => {
left = {
type: 'BinaryExpression',
operator: '+',
left: left,
right: this.visit(rhs),
};
});
}
return left;
}
callExpression(ctx) {
let callee = this.visit(ctx.memberExpression);
if (ctx.LParen) {
return {
type: 'CallExpression',
callee: callee,
arguments: ctx.argumentList ? this.visit(ctx.argumentList) : [],
};
}
return callee;
}
argumentList(ctx) {
return ctx.expression.map(expr => this.visit(expr));
}
memberExpression(ctx) {
let obj = this.visit(ctx.primary);
if (ctx.Identifier) {
ctx.Identifier.forEach(propIdent => {
obj = {
type: 'MemberExpression',
object: obj,
property: { type: 'Identifier', name: propIdent.image },
};
});
}
return obj;
}
primary(ctx) {
if (ctx.literal) return this.visit(ctx.literal);
if (ctx.Identifier) return { type: 'Identifier', name: ctx.Identifier[0].image };
if (ctx.block) return this.visit(ctx.block);
if (ctx.expression) return this.visit(ctx.expression);
}
literal(ctx) {
if (ctx.Number) return { type: 'NumericLiteral', value: Number(ctx.Number[0].image) };
if (ctx.String) return { type: 'StringLiteral', value: ctx.String[0].image };
}
block(ctx) {
return {
type: 'Block',
properties: ctx.keyValuePairs ? this.visit(ctx.keyValuePairs) : []
};
}
keyValuePairs(ctx) {
return ctx.keyValuePair.map(kv => this.visit(kv));
}
keyValuePair(ctx) {
return {
type: 'Property',
key: ctx.Identifier[0].image,
value: this.visit(ctx.expression)
};
}
}
export const astBuilder = new AstBuilder();