Fix unary expression stand-alone bug

Author: 1001mei

src/ast/types/blocks-and-statements.ts

@@ -79,7 +79,7 @@ export interface ExpressionStatement extends BaseNode {
   stmtExp: StatementExpression;
 }
 
-export type StatementExpression = MethodInvocation | Assignment;
+export type StatementExpression = MethodInvocation | Assignment | UnaryExpression;
 
 export interface MethodInvocation extends BaseNode {
   kind: "MethodInvocation";
@@ -142,13 +142,13 @@ export interface ClassInstanceCreationExpression extends BaseNode {
 export interface Literal extends BaseNode {
   kind: "Literal";
   literalType:
-    | IntegerLiteral
-    | FloatingPointLiteral
-    | BooleanLiteral
-    | CharacterLiteral
-    | TextBlockLiteral
-    | StringLiteral
-    | NullLiteral;
+  | IntegerLiteral
+  | FloatingPointLiteral
+  | BooleanLiteral
+  | CharacterLiteral
+  | TextBlockLiteral
+  | StringLiteral
+  | NullLiteral;
 }
 
 export type IntegerLiteral =
@@ -243,18 +243,18 @@ export interface Assignment extends BaseNode {
   kind: "Assignment";
   left: LeftHandSide;
   operator:
-    | "="
-    | "+="
-    | "-="
-    | "*="
-    | "/="
-    | "%="
-    | "|="
-    | "&="
-    | "^="
-    | "<<="
-    | ">>="
-    | ">>>=";
+  | "="
+  | "+="
+  | "-="
+  | "*="
+  | "/="
+  | "%="
+  | "|="
+  | "&="
+  | "^="
+  | "<<="
+  | ">>="
+  | ">>>=";
   right: Expression;
 }
 

src/compiler/__tests__/tests/unaryExpression.test.ts

@@ -4,6 +4,27 @@ import {
 } from "../__utils__/test-utils";
 
 const testCases: testCase[] = [
+  {
+    comment: "single increment/decrement statement",
+    program: `
+    public class Main {
+      public static void main(String[] args) {
+        int a = 1;
+        int b = 2;
+
+        ++a;
+        b++;
+        System.out.println(a);
+        System.out.println(b);
+
+        a--;
+        --b;
+        System.out.println(a);
+        System.out.println(b);
+      }
+    }`,
+    expectedLines: ["2", "3", "1", "2"],
+  },
   {
     comment: "postfix increment/decrement",
     program: `

src/compiler/code-generator.ts

@@ -550,6 +550,9 @@ const codeGenerators: { [type: string]: (node: Node, cg: CodeGenerator) => Compi
 
   ExpressionStatement: (node: Node, cg: CodeGenerator) => {
     const { stmtExp } = node as ExpressionStatement
+    if (stmtExp.kind === 'PrefixExpression' || stmtExp.kind === 'PostfixExpression') {
+      return codeGenerators['IncrementDecrementExpression'](stmtExp, cg)
+    }
     return compile(stmtExp, cg)
   },
 
@@ -708,6 +711,18 @@ const codeGenerators: { [type: string]: (node: Node, cg: CodeGenerator) => Compi
     }
   },
 
+  IncrementDecrementExpression: (node: Node, cg: CodeGenerator) => {
+    // handle cases of ++x, x++, x--, --x that do not add object to operand stack
+    if (node.kind === 'PrefixExpression' || node.kind === 'PostfixExpression') {
+      const { name } = node.expression as ExpressionName
+      const info = cg.symbolTable.queryVariable(name)
+      if (!Array.isArray(info)) {
+        cg.code.push(OPCODE.IINC, info.index, node.operator === '++' ? 1 : -1)
+      }
+    }
+    return { stackSize: 0, resultType: EMPTY_TYPE }
+  },
+
   PrefixExpression: (node: Node, cg: CodeGenerator) => {
     const { operator: op, expression: expr } = node as PrefixExpression
     if (op === '++' || op === '--') {

src/compiler/grammar.pegjs

@@ -862,11 +862,20 @@ ForUpdate
 
 StatementExpressionList
   = head:StatementExpression tail:(comma @StatementExpression)* {
-    return [head, ...tail];
+    return [head, ...tail].map(s => {
+      return {
+        kind: "ExpressionStatement", stmtExp: s
+      }
+    });
   }
 
 ExpressionStatement
-  = @StatementExpression semicolon
+  = se:StatementExpression semicolon {
+    return {
+      kind: "ExpressionStatement",
+      stmtExp: se,
+    }
+  }
 
 StatementExpression
   = Assignment

src/compiler/grammar.ts

@@ -864,11 +864,20 @@ ForUpdate
 
 StatementExpressionList
   = head:StatementExpression tail:(comma @StatementExpression)* {
-    return [head, ...tail];
+    return [head, ...tail].map(s => {
+      return {
+        kind: "ExpressionStatement", stmtExp: s
+      }
+    });
   }
 
 ExpressionStatement
-  = @StatementExpression semicolon
+  = se:StatementExpression semicolon {
+    return {
+      kind: "ExpressionStatement",
+      stmtExp: se,
+    }
+  }
 
 StatementExpression
   = Assignment

src/compiler/import/lib-info.ts

@@ -34,7 +34,25 @@ export const rawLibInfo = {
             "public void println(float)",
             "public void println(double)",
             "public void println(char)",
-            "public void println(boolean)"
+            "public void println(boolean)",
+            "public void print(java.lang.String)",
+            "public void print(int)",
+            "public void print(long)",
+            "public void print(float)",
+            "public void print(double)",
+            "public void print(char)",
+            "public void print(boolean)"
+          ]
+        }
+      ]
+    },
+    {
+      "name": "java.util",
+      "classes": [
+        {
+          "name": "public java.util.Arrays",
+          "methods": [
+            "public static java.lang.String toString(int[])"
           ]
         }
       ]