feat(parser): create pie parser and export it

packages/parser/src/language/index.ts

@@ -4,3 +4,4 @@ export * from './generated/module.js';
 
 export * from './common/index.js';
 export * from './info/index.js';
+export * from './pie/index.js';

packages/parser/src/language/pie/index.ts

@@ -0,0 +1 @@
+export * from './pieModule.js';

packages/parser/src/language/pie/pie.langium

@@ -0,0 +1,20 @@
+grammar Pie
+import "../common/common";
+
+entry Pie:
+  NEWLINE*
+  "pie" showData?="showData"?
+  (
+    NEWLINE* TitleAndAccessibilities sections+=PieSection*
+    | NEWLINE+ sections+=PieSection+
+    | NEWLINE*
+  )
+;
+
+PieSection:
+  label=PIE_SECTION_LABEL ":" value=PIE_SECTION_VALUE
+  NEWLINE+
+;
+
+terminal PIE_SECTION_LABEL: /"[^"]+"/;
+terminal PIE_SECTION_VALUE returns number: /(0|[1-9][0-9]*)(\.[0-9]+)?/;

packages/parser/src/language/pie/pieModule.ts

@@ -0,0 +1,68 @@
+import type {
+  DefaultSharedModuleContext,
+  LangiumServices,
+  LangiumSharedServices,
+  Module,
+  PartialLangiumServices,
+} from 'langium';
+import { EmptyFileSystem, createDefaultModule, createDefaultSharedModule, inject } from 'langium';
+
+import { MermaidGeneratedSharedModule, PieGeneratedModule } from '../generated/module.js';
+import { CommonLexer } from '../common/commonLexer.js';
+import { PieTokenBuilder } from './pieTokenBuilder.js';
+import { PieValueConverter } from './pieValueConverter.js';
+
+/**
+ * Declaration of `Pie` services.
+ */
+type PieAddedServices = {
+  parser: {
+    Lexer: CommonLexer;
+    TokenBuilder: PieTokenBuilder;
+    ValueConverter: PieValueConverter;
+  };
+};
+
+/**
+ * Union of Langium default services and `Pie` services.
+ */
+export type PieServices = LangiumServices & PieAddedServices;
+
+/**
+ * Dependency injection module that overrides Langium default services and
+ * contributes the declared `Pie` services.
+ */
+const PieModule: Module<PieServices, PartialLangiumServices & PieAddedServices> = {
+  parser: {
+    Lexer: (services) => new CommonLexer(services),
+    TokenBuilder: () => new PieTokenBuilder(),
+    ValueConverter: () => new PieValueConverter(),
+  },
+};
+
+/**
+ * Create the full set of services required by Langium.
+ *
+ * First inject the shared services by merging two modules:
+ *  - Langium default shared services
+ *  - Services generated by langium-cli
+ *
+ * Then inject the language-specific services by merging three modules:
+ *  - Langium default language-specific services
+ *  - Services generated by langium-cli
+ *  - Services specified in this file
+ * @param context - Optional module context with the LSP connection
+ * @returns An object wrapping the shared services and the language-specific services
+ */
+export function createPieServices(context: DefaultSharedModuleContext = EmptyFileSystem): {
+  shared: LangiumSharedServices;
+  Pie: PieServices;
+} {
+  const shared: LangiumSharedServices = inject(
+    createDefaultSharedModule(context),
+    MermaidGeneratedSharedModule
+  );
+  const Pie: PieServices = inject(createDefaultModule({ shared }), PieGeneratedModule, PieModule);
+  shared.ServiceRegistry.register(Pie);
+  return { shared, Pie };
+}

packages/parser/src/language/pie/pieTokenBuilder.ts

@@ -0,0 +1,23 @@
+import type { GrammarAST, Stream, TokenBuilderOptions } from 'langium';
+import { DefaultTokenBuilder } from 'langium';
+
+import type { TokenType } from '../chevrotainWrapper.js';
+
+export class PieTokenBuilder extends DefaultTokenBuilder {
+  protected override buildKeywordTokens(
+    rules: Stream<GrammarAST.AbstractRule>,
+    terminalTokens: TokenType[],
+    options?: TokenBuilderOptions
+  ): TokenType[] {
+    const tokenTypes: TokenType[] = super.buildKeywordTokens(rules, terminalTokens, options);
+    tokenTypes.forEach((tokenType: TokenType): void => {
+      if (
+        (tokenType.name === 'pie' || tokenType.name === 'showData') &&
+        tokenType.PATTERN !== undefined
+      ) {
+        tokenType.PATTERN = new RegExp(tokenType.PATTERN.toString() + '(?!\\S)');
+      }
+    });
+    return tokenTypes;
+  }
+}

packages/parser/src/language/pie/pieValueConverter.ts

@@ -0,0 +1,50 @@
+import type { CstNode, GrammarAST, ValueType } from 'langium';
+import { DefaultValueConverter } from 'langium';
+
+import { CommonValueConverter } from '../common/commonValueConverters.js';
+
+export class PieValueConverter extends DefaultValueConverter {
+  protected override runConverter(
+    rule: GrammarAST.AbstractRule,
+    input: string,
+    cstNode: CstNode
+  ): ValueType {
+    let value: ValueType | undefined = CommonValueConverter.customRunConverter(
+      rule,
+      input,
+      cstNode
+    );
+    if (value === undefined) {
+      value = PieValueConverter.customRunConverter(rule, input, cstNode);
+    }
+
+    if (value === undefined) {
+      return super.runConverter(rule, input, cstNode);
+    } else {
+      return value;
+    }
+  }
+
+  /**
+   * A method contains convert logic to be used by class itself or `MermaidValueConverter`.
+   *
+   * @param rule - Parsed rule.
+   * @param input - Matched string.
+   * @param _cstNode - Node in the Concrete Syntax Tree (CST).
+   * @returns converted the value if it's pie rule or `null` if it's not.
+   */
+  public static customRunConverter(
+    rule: GrammarAST.AbstractRule,
+    input: string,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    _cstNode: CstNode
+  ): ValueType | undefined {
+    if (rule.name === 'PIE_SECTION_LABEL') {
+      return input
+        .replace(/"/g, '')
+        .trim()
+        .replaceAll(/[\t ]{2,}/gm, ' ');
+    }
+    return undefined;
+  }
+}