add stringify function #30

ts-graphviz · Aug 2, 2021 · 2631b76 · 2631b76
1 parent 7e83c87
commit 2631b76
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diff --git a/src/index.ts b/src/index.ts
@@ -1,5 +1,6 @@
 export { SyntaxError } from './dot.peggy';
 export { AST } from './ast';
 export { convert } from './convert';
+export { stringify } from './stringify';
 export { parse } from './parse';
 export { dot } from './dot';
diff --git a/src/stringify.ts b/src/stringify.ts
@@ -0,0 +1,88 @@
+import { AST } from './ast';
+
+export interface StringifyOption {
+  directed?: boolean;
+  indentSize?: number;
+}
+
+class Compiler {
+  private directed: boolean;
+  private indentSize: number;
+  constructor({ directed = true, indentSize = 2 }: StringifyOption = {}) {
+    this.directed = directed;
+    this.indentSize = indentSize;
+  }
+
+  private indent(line: string): string {
+    return ' '.repeat(this.indentSize) + line;
+  }
+  private pad(pad: string): (l: string) => string {
+    return (l: string) => pad + l;
+  }
+  public stringify(ast: AST.ASTNode): string {
+    switch (ast.type) {
+      case AST.Types.Attribute:
+        return `${this.stringify(ast.key)} = ${this.stringify(ast.value)};`;
+      case AST.Types.Attributes:
+        return `${ast.kind} [\n${ast.body.map(this.stringify.bind(this)).map(this.indent).join('\n')}\n]`;
+      case AST.Types.Comment:
+        switch (ast.kind) {
+          case AST.Comment.Kind.Block:
+            return '/**\n' + ast.value.split('\n').map(this.pad(' * ')).join('\n') + '\n */';
+          case AST.Comment.Kind.Slash:
+            return ast.value.split('\n').map(this.pad('// ')).join('\n');
+          case AST.Comment.Kind.Macro:
+            return ast.value.split('\n').map(this.pad('# ')).join('\n');
+        }
+      case AST.Types.Dot:
+        return ast.body.map(this.stringify.bind(this)).join('\n');
+      case AST.Types.Edge:
+        return `${ast.targets.map(this.stringify.bind(this)).join(this.directed ? ' -> ' : ' -- ')} [\n${ast.body
+          .map(this.stringify.bind(this))
+          .map(this.indent)
+          .join('\n')}\n];`;
+      case AST.Types.Node:
+        return `${this.stringify(ast.id)} [\n${ast.body
+          .map(this.stringify.bind(this))
+          .map(this.indent)
+          .join('\n')}\n];`;
+      case AST.Types.NodeRef:
+        return [this.stringify(ast.id), ast.port ? this.stringify(ast.port) : null, ast.compass ? ast.compass : null]
+          .filter((v) => v !== null)
+          .join(':');
+      case AST.Types.NodeRefGroup:
+        return `{${ast.body.map(this.stringify).join(' ')}}`;
+      case AST.Types.Graph:
+        this.directed = ast.directed;
+        return [
+          ast.strict ? 'strict' : null,
+          ast.directed ? 'digraph' : 'graph',
+          ast.id ? this.stringify(ast.id) : null,
+          `{\n${ast.body.map(this.stringify).map(this.indent).join('\n')}\n}`,
+        ]
+          .filter((v) => v !== null)
+          .join(' ');
+      case AST.Types.Subgraph:
+        return [
+          'subgraph',
+          ast.id ? this.stringify(ast.id) : null,
+          `{\n${ast.body.map(this.stringify).map(this.indent).join('\n')}\n}`,
+        ]
+          .filter((v) => v !== null)
+          .join(' ');
+      case AST.Types.Literal:
+        switch (ast.quoted) {
+          case true:
+            return `"${ast.value}"`;
+          case false:
+            return ast.value;
+          case 'html':
+            return `<${ast.value}>`;
+        }
+    }
+  }
+}
+
+export function stringify(ast: AST.ASTNode, options?: StringifyOption): string {
+  return new Compiler(options).stringify(ast);
+}