Implement println (instead of print).

Author: mayth

AST.c

@@ -36,6 +36,13 @@ AST* AST_makeValue(int v) {
   return p;
 }
 
+AST *AST_makeString(const char *str) {
+  AST *p = AST_alloc();
+  p->code = VAL_STRING;
+  p->AST_string = str;
+  return p;
+}
+
 AST *AST_makeUnary(CodeType code, AST *node) {
   AST *p = AST_alloc();
   p->code = code;

AST.h

@@ -18,7 +18,8 @@ enum code_ {
     ETC_LIST,
     VAL_NUM,
     VAL_SYMBOL,
-    CODE_PRINT,
+    VAL_STRING,
+    CODE_PRINTLN,
     CODE_FUNC,
     CODE_VAR,
     CODE_RETURN,
@@ -74,6 +75,9 @@ struct AST_ {
         /* For value (leaf node) */
         int value;
 
+        /* For string */
+        const char *str;
+
         /* For symbol */
         Symbol *symbol;
 
@@ -96,6 +100,7 @@ struct AST_ {
 };
 
 #define AST_value un.value
+#define AST_string un.str
 /* For Unary Expression */
 #define AST_unary un.unary
 /* For Binary Expression */
@@ -112,6 +117,7 @@ struct AST_ {
 
 /* Normal Expression */
 AST *AST_makeValue(int v);
+AST *AST_makeString(const char *str);
 AST *AST_makeUnary(CodeType type, AST *node);
 AST *AST_makeBinary(CodeType type, AST *left, AST *right);
 AST *AST_makeTrinary(CodeType type, AST *first, AST *second, AST *third);

interpreter.c

@@ -39,7 +39,7 @@ int executeArrayAssign(AST *ast, AST *idx, AST *expr);
 int resolveSymbol(const Symbol *symbol, const size_t index);
 
 int main() {
-    yydebug = 0;
+    yydebug = 1;
     SymbolTable = StrSymMap_new();
     Env = Stack_new();
     printf("*** start parsing ***\n");
@@ -201,8 +201,15 @@ int executeArrayAssign(AST *sym, AST *idx, AST *expr) {
     return arrayAssign(sym->AST_symbol, executeExpression(idx), executeExpression(expr));
 }
 
-void executePrint(AST *ast) {
-    printf("%d\n", executeExpression(ast->AST_unary));
+void executePrintln(AST *ast) {
+    const char *format = ast->AST_left->AST_string;
+    if (ast->AST_right) {
+        const int val = executeExpression(ast->AST_right);
+        printf(format, val);
+    } else {
+        printf(format);
+    }
+    printf("\n");
 }
 
 int executeStatements(ASTVector *statements) {
@@ -232,8 +239,8 @@ bool executeStatement(AST *ast) {
         case ETC_LIST:
             executeStatements(ast->AST_list);
             break;
-        case CODE_PRINT:
-            executePrint(ast);
+        case CODE_PRINTLN:
+            executePrintln(ast);
             break;
         case CODE_RETURN:
             if (ast->AST_unary) {

lexer.c

@@ -3,6 +3,8 @@
 #include <ctype.h>
 #include "AST.h"
 
+#define INITIAL_STR_LEN (128)
+
 int take() {
     int c;
     while (isspace(c = getc(stdin))) { }
@@ -26,6 +28,7 @@ int yylex() {
         case '[':
         case ']':
         case ';':
+        case ',':
             return c;
     }
     if (c == '=') {
@@ -60,6 +63,18 @@ int yylex() {
         ungetc(next, stdin);
         return c;
     }
+    if (c == '"') {
+        char *str = (char *)malloc(sizeof(char) * INITIAL_STR_LEN);
+        char *s = str;
+        c = getc(stdin);    // skip current '"'
+        for (; c != '"'; c = getc(stdin), ++s) {
+            *s = c;
+        }
+        *s = '\0';
+        yylval.val = AST_makeString(strdup(str));
+        free(str);
+        return STRING;
+    }
     if (isdigit(c)) {
         int n;
         for (n = 0; isdigit(c); c = getc(stdin)) {
@@ -78,8 +93,8 @@ int yylex() {
         *s = '\0';
         ungetc(c, stdin);
         int retval = 0;
-        if (strcmp(str, "print") == 0) {
-            retval = PRINT;
+        if (strcmp(str, "println") == 0) {
+            retval = PRINTLN;
         } else if (strcmp(str, "var") == 0) {
             retval = VAR;
         } else if (strcmp(str, "return") == 0) {

parser.y

@@ -1,9 +1,10 @@
-%token PRINT
+%token PRINTLN
 %token VAR
 %token RETURN
 %token FOR
 %token SYMBOL
 %token NUMBER
+%token STRING
 %token OP_EQ
 %token OP_NEQ
 %token OP_LE
@@ -37,7 +38,7 @@
 %type <val> function_definition param_list symbol_list
 %type <val> variable_names
 %type <val> argument_list arguments
-%type <val> SYMBOL NUMBER
+%type <val> SYMBOL NUMBER STRING
 
 %start program
 
@@ -86,7 +87,9 @@ statement: expression ';'
          | RETURN ';' { $$ = AST_makeUnary(CODE_RETURN, NULL); }
          | for_statement
 
-print_statement: PRINT expression { $$ = AST_makeUnary(CODE_PRINT, $2); }
+print_statement: PRINTLN '(' STRING ')' { $$ = AST_makeBinary(CODE_PRINTLN, $3, NULL); }
+               | PRINTLN '(' STRING ',' expression ')'
+               { $$ = AST_makeBinary(CODE_PRINTLN, $3, $5); }
 
 for_statement: FOR '(' expression ';' expression ';' expression ')' stmt_or_block
              { $$ = AST_makeFor($3, $5, $7, $9); }