style: split matchers from mermaid-token-builder

packages/mermaid-parser/src/language/mermaid-token-builder.ts

@@ -1,62 +1,13 @@
 /* eslint-disable unicorn/no-null */
-import {
-    CustomPatternMatcherFunc,
-    CustomPatternMatcherReturn,
-    EOF,
-    TokenType,
-} from 'chevrotain';
+import { EOF, TokenType } from 'chevrotain';
 import { DefaultTokenBuilder } from 'langium';
 import { TerminalRule } from 'langium/lib/grammar/generated/ast';
 
-/**
- * Matches a single title
- */
-const titleRegex = /(?:^|[\t ]+)title(?:[\t ]+([^\n]*)|$)/;
-const matchTitle: CustomPatternMatcherFunc = (string_: string) => {
-    const match = titleRegex.exec(string_);
-    if (match && match[1] !== undefined) {
-        return [match[1].trim()];
-    }
-    return null;
-};
-
-/**
- * Matches a single accessible title
- */
-const accumulatorTitleRegex = /(?:^|[\t ]+)accTitle[\t ]*:[\t ]*([^\n]+)?/;
-const matchAccumulatorTitle: CustomPatternMatcherFunc = (string_: string) => {
-    let result = null;
-    let match = accumulatorTitleRegex.exec(string_);
-    while (match !== null) {
-        result = match[1] === undefined ? null : [match[1].trim()];
-        string_ = string_.replace(match[0], '');
-        match = accumulatorTitleRegex.exec(string_);
-    }
-    return result as CustomPatternMatcherReturn;
-};
-
-/**
- * Matches single and multiline accessible description
- */
-const accumulatorDescrRegex =
-    // eslint-disable-next-line regexp/strict
-    /(?:^|[\t ]+)accDescr(?:[\t ]*:[\t ]*([^\n]+)?|\s*{([^}]+)?})/;
-const matchAccumulatorDescr: CustomPatternMatcherFunc = (string_: string) => {
-    const match = accumulatorDescrRegex.exec(string_);
-    if (match) {
-        // single line description
-        if (match[1] !== undefined) {
-            return [match[1].trim()];
-        }
-
-        // multi line description
-        if (match[2] !== undefined) {
-            const result = match[2].replaceAll(/^\s*|\s+$/gm, '');
-            return result ? [result] : null;
-        }
-    }
-    return null;
-};
+import {
+    matchAccessibilityDescr,
+    matchAccessibilityTitle,
+    matchTitle,
+} from '../matchers';
 
 export class MermiadTokenBuilder extends DefaultTokenBuilder {
     override buildTerminalToken(terminal: TerminalRule): TokenType {
@@ -68,13 +19,13 @@ export class MermiadTokenBuilder extends DefaultTokenBuilder {
             }
             case 'ACC_DESCR': {
                 tokenType.LINE_BREAKS = true;
-                tokenType.PATTERN = matchAccumulatorDescr;
+                tokenType.PATTERN = matchAccessibilityDescr;
                 tokenType.START_CHARS_HINT = ['accDescr'];
                 break;
             }
             case 'ACC_TITLE': {
                 tokenType.LINE_BREAKS = false;
-                tokenType.PATTERN = matchAccumulatorTitle;
+                tokenType.PATTERN = matchAccessibilityTitle;
                 tokenType.START_CHARS_HINT = ['accTitle'];
                 break;
             }

packages/mermaid-parser/src/matchers/accdescr.ts

@@ -0,0 +1,28 @@
+/* eslint-disable unicorn/no-null */
+import { CustomPatternMatcherFunc } from 'chevrotain';
+
+/**
+ * Matches single and multiline accessible description
+ */
+const accessibilityDescrRegex =
+    // eslint-disable-next-line regexp/strict
+    /(?:^|[\t ]+)accDescr(?:[\t ]*:[\t ]*([^\n]+)?|\s*{([^}]+)?})/;
+export const matchAccessibilityDescr: CustomPatternMatcherFunc = (
+    string_: string,
+) => {
+    const match = accessibilityDescrRegex.exec(string_);
+    if (match) {
+        // single line description
+        if (match[1] !== undefined) {
+            return [match[1].trim()];
+        }
+
+        // multi line description
+        if (match[2] !== undefined) {
+            const result = match[2].replaceAll(/^\s*|\s+$/gm, '');
+            return result ? [result] : null;
+        }
+    }
+    return null;
+};
+/* eslint-enable unicorn/no-null */

packages/mermaid-parser/src/matchers/acctitle.ts

@@ -0,0 +1,23 @@
+/* eslint-disable unicorn/no-null */
+import {
+    CustomPatternMatcherFunc,
+    CustomPatternMatcherReturn,
+} from 'chevrotain';
+
+/**
+ * Matches a single accessible title
+ */
+const accessibilityTitleRegex = /(?:^|[\t ]+)accTitle[\t ]*:[\t ]*([^\n]+)?/;
+export const matchAccessibilityTitle: CustomPatternMatcherFunc = (
+    string_: string,
+) => {
+    let result: CustomPatternMatcherReturn | null = null;
+    let match = accessibilityTitleRegex.exec(string_);
+    while (match !== null) {
+        result = match[1] === undefined ? null : [match[1].trim()];
+        string_ = string_.replace(match[0], '');
+        match = accessibilityTitleRegex.exec(string_);
+    }
+    return result;
+};
+/* eslint-enable unicorn/no-null */

packages/mermaid-parser/src/matchers/index.ts

@@ -0,0 +1,3 @@
+export * from './accdescr';
+export * from './acctitle';
+export * from './title';

packages/mermaid-parser/src/matchers/title.ts

@@ -0,0 +1,15 @@
+/* eslint-disable unicorn/no-null */
+import { CustomPatternMatcherFunc } from 'chevrotain';
+
+/**
+ * Matches a single title
+ */
+const titleRegex = /(?:^|[\t ]+)title(?:[\t ]+([^\n]*)|$)/;
+export const matchTitle: CustomPatternMatcherFunc = (string_: string) => {
+    const match = titleRegex.exec(string_);
+    if (match && match[1] !== undefined) {
+        return [match[1].trim()];
+    }
+    return null;
+};
+/* eslint-enable unicorn/no-null */