Replace sample language with deadfish

2021-12-18 18:16:22 +05:30
parent bb9e85f422
commit 3ace388d90
8 changed files with 161 additions and 141 deletions
--- a/engines/deadfish/engine.ts
+++ b/engines/deadfish/engine.ts
@@ -0,0 +1,87 @@
+import { setupWorker } from "../setup-worker";
+import { DocumentRange, LanguageEngine, StepExecutionResult } from "../types";
+import { DFAstStep, DFRS, DF_OP } from "./constants";
+
+// Default values for internal states
+// Factories are used to create new objects on reset
+const DEFAULT_AST = (): DFAstStep[] => [];
+const DEFAULT_PC = -1;
+const DEFAULT_VALUE = 0;
+
+// Instruction characters
+const OP_CHARS = Object.values(DF_OP);
+
+class DeadfishLanguageEngine implements LanguageEngine<DFRS> {
+  private _ast: DFAstStep[] = DEFAULT_AST();
+  private _value: number = DEFAULT_VALUE;
+  private _pc: number = DEFAULT_PC;
+
+  resetState() {
+    this._ast = DEFAULT_AST();
+    this._value = DEFAULT_VALUE;
+    this._pc = DEFAULT_PC;
+  }
+
+  prepare(code: string, _input: string) {
+    this._ast = this.parseCode(code);
+  }
+
+  executeStep(): StepExecutionResult<DFRS> {
+    // Execute and update program counter
+    let output: string | undefined = undefined;
+    if (this._pc !== -1) {
+      const astStep = this._ast[this._pc];
+      output = this.processOp(astStep.instr);
+    }
+    this._pc += 1;
+
+    // Prepare location of next step
+    let nextStepLocation: DocumentRange | null = null;
+    if (this._pc < this._ast.length) {
+      const { line, char } = this._ast[this._pc].location;
+      const charRange = { start: char, end: char + 1 };
+      nextStepLocation = { line, charRange };
+    }
+
+    // Prepare and return execution result
+    const rendererState = { value: this._value };
+    return { rendererState, nextStepLocation, output };
+  }
+
+  private parseCode(code: string) {
+    const ast: DFAstStep[] = [];
+
+    // For each line...
+    code.split("\n").forEach((line, lIdx) => {
+      // For each character of this line...
+      line.split("").forEach((char, cIdx) => {
+        if (OP_CHARS.includes(char as DF_OP)) {
+          ast.push({
+            instr: char as DF_OP,
+            location: { line: lIdx + 1, char: cIdx + 1 },
+          });
+        }
+      });
+    });
+
+    return ast;
+  }
+
+  /**
+   * Process the given instruction and return string to push to output if any.
+   *
+   * @param instr Instruction to apply
+   * @returns String to append to output, if any
+   */
+  private processOp(instr: DF_OP): string | undefined {
+    if (instr === DF_OP.INCR) ++this._value;
+    else if (instr === DF_OP.DECR) --this._value;
+    else if (instr === DF_OP.SQ) this._value = this._value * this._value;
+    else if (instr === DF_OP.OUT) return this._value.toString();
+    else throw new Error("Invalid instruction");
+
+    if (this._value === -1 || this._value === 256) this._value = 0;
+  }
+}
+
+setupWorker(new DeadfishLanguageEngine());