1 files changed, 80 insertions, 0 deletions
diff --git a/llparse/src/compiler/header-builder.ts b/llparse/src/compiler/header-builder.ts
new file mode 100644
index 0000000..9f5bee7
--- /dev/null
+++ b/llparse/src/compiler/header-builder.ts
@@ -0,0 +1,80 @@
+import * as frontend from 'llparse-frontend';
+import source = frontend.source;
+
+export interface IHeaderBuilderOptions {
+  readonly prefix: string;
+  readonly headerGuard?: string;
+  readonly properties: ReadonlyArray<source.Property>;
+  readonly spans: ReadonlyArray<frontend.SpanField>;
+}
+
+export class HeaderBuilder {
+  public build(options: IHeaderBuilderOptions): string {
+    let res = '';
+    const PREFIX = options.prefix.toUpperCase().replace(/[^a-z]/gi, '_');
+    const DEFINE = options.headerGuard === undefined ?
+      `INCLUDE_${PREFIX}_H_` : options.headerGuard;
+
+    res += `#ifndef ${DEFINE}\n`;
+    res += `#define ${DEFINE}\n`;
+    res += '#ifdef __cplusplus\n';
+    res += 'extern "C" {\n';
+    res += '#endif\n';
+    res += '\n';
+
+    res += '#include <stdint.h>\n';
+    res += '\n';
+
+    // Structure
+    res += `typedef struct ${options.prefix}_s ${options.prefix}_t;\n`;
+    res += `struct ${options.prefix}_s {\n`;
+    res += '  int32_t _index;\n';
+
+    for (const [ index, field ] of options.spans.entries()) {
+      res += `  void* _span_pos${index};\n`;
+      if (field.callbacks.length > 1) {
+        res += `  void* _span_cb${index};\n`;
+      }
+    }
+
+    res += '  int32_t error;\n';
+    res += '  const char* reason;\n';
+    res += '  const char* error_pos;\n';
+    res += '  void* data;\n';
+    res += '  void* _current;\n';
+
+    for (const prop of options.properties) {
+      let ty: string;
+      if (prop.ty === 'i8') {
+        ty = 'uint8_t';
+      } else if (prop.ty === 'i16') {
+        ty = 'uint16_t';
+      } else if (prop.ty === 'i32') {
+        ty = 'uint32_t';
+      } else if (prop.ty === 'i64') {
+        ty = 'uint64_t';
+      } else if (prop.ty === 'ptr') {
+        ty = 'void*';
+      } else {
+        throw new Error(
+          `Unknown state property type: "${prop.ty}"`);
+      }
+      res += `  ${ty} ${prop.name};\n`;
+    }
+    res += '};\n';
+
+    res += '\n';
+
+    res += `int ${options.prefix}_init(${options.prefix}_t* s);\n`;
+    res += `int ${options.prefix}_execute(${options.prefix}_t* s, ` +
+      'const char* p, const char* endp);\n';
+
+    res += '\n';
+    res += '#ifdef __cplusplus\n';
+    res += '}  /* extern "C" *\/\n';
+    res += '#endif\n';
+    res += `#endif  /* ${DEFINE} *\/\n`;
+
+    return res;
+  }
+}