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projects/12/archive/String.jack

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+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: projects/12/String.jack
+
+/**
+ * Represents character strings. In addition for constructing and disposing
+ * strings, the class features methods for getting and setting individual
+ * characters of the string, for erasing the string's last character,
+ * for appending a character to the string's end, and more typical
+ * string-oriented operations.
+ */
+class String { 
+    field Array str;
+    field int length;
+    static bool neg;
+
+    /** constructs a new empty string with a maximum length of maxLength
+     *  and initial length of 0. */
+    constructor String new(int maxLength) {
+        if (maxLength > 0){
+            let str = Array.new(maxLength);
+        }
+        let length = 0;
+        return this;
+    }
+
+    /** Disposes this string. */
+    method void dispose() {
+        if(length > 0){
+            do str.dispose();
+        }
+        do Memory.deAlloc(this);
+        return;
+    }
+
+    /** Returns the current length of this string. */
+    method int length() {
+        return length;
+    }
+
+    /** Returns the character at the j-th location of this string. */
+    method char charAt(int j) {
+        if(j > length){
+            do Sys.error(7);
+        }
+        return str[j];          
+    }
+
+    /** Sets the character at the j-th location of this string to c. */
+    method void setCharAt(int j, char c) {
+        if(j > length){
+            do Sys.error(7);
+        }
+        let str[j] = c;
+        return;
+    }
+
+    /** Appends c to this string's end and returns this string. */
+    method String appendChar(char c) {
+        let str[length] = c;
+        let length = length + 1;
+        return this;
+    }
+
+    /** Erases the last character from this string. */
+    method void eraseLastChar() {
+        let str[length] = 0;
+        let length = length - 1;
+        return;
+    }
+
+    /** Returns the integer value of this string, 
+     *  until a non-digit character is detected. */
+    method int intValue() {
+        var int d, sum, i;
+        var bool f;
+        while(i < length){
+            let d = str[i]; // kak da go zavyrtq v realen int
+            if ((d > 47) & (d < 58)){
+                let sum = (sum * 10) + (d - 48);
+            }
+            else{
+                if((i = 0) & (d = 45)){
+                    let f = true;
+                }
+                else{
+                    let i = length;
+                }
+            }
+            let i = i + 1;
+        }
+        if (f){
+            return -sum;
+        }
+        return sum;
+    }
+
+    /** Sets this string to hold a representation of the given value. */
+    method void setInt(int val) {
+        var int lastDigit, a,i;
+        var char c;
+        if(val < 0){
+            let neg = true;
+            let val = -val;
+        }
+        let a = val / 10;
+        let lastDigit = val - (a * 10);
+        let i = 48;
+        while (i < 58){
+            if (i = (48 + lastDigit)){
+                let c = i;
+                let i = 59;
+            }
+            let i = i + 1;
+        }
+        if (val < 10){
+            let length = 0;
+            if (neg){
+                let neg = false;
+                do this.appendChar(45);
+            }
+            
+            do this.appendChar(c);
+            return;
+        }
+        else{
+            do this.setInt(a);
+            do this.appendChar(c);
+        }
+        return;
+    }
+
+    /** Returns the new line character. */
+    function char newLine() {
+        return 128;
+    }
+
+    /** Returns the backspace character. */
+    function char backSpace() {
+        return 129;
+    }
+
+    /** Returns the double quote (") character. */
+    function char doubleQuote() {
+        return 34;
+    }
+}