PLC Laboratory 9 - Revision history

Beh01: /* Compiler of Arithmetic Expressions Using ANTLR */

2024-04-17T07:48:52Z

Compiler of Arithmetic Expressions Using ANTLR

Beh01: /* Example */

2024-04-17T07:44:18Z

Example

Beh01: /* Example */

2024-04-17T06:54:22Z

Example

Beh01: /* Compiler of Arithmetic Expressions Using ANTLR */

2024-04-17T06:46:58Z

Compiler of Arithmetic Expressions Using ANTLR

Beh01: /* Compiler of Arithmetic Expressions Using ANTLR */

2024-04-17T06:14:35Z

Compiler of Arithmetic Expressions Using ANTLR

Beh01: /* Example */

2024-04-16T16:43:16Z

Example

Beh01 at 16:39, 16 April 2024

2024-04-16T16:39:44Z

Beh01: /* Example */

2024-04-16T12:10:29Z

Example

Beh01: /* Compiler of Arithmetic Expressions Using ANTLR */

2024-04-16T11:57:39Z

Compiler of Arithmetic Expressions Using ANTLR

Beh01: /* Compiler of Arithmetic Expressions Using ANTLR */

2024-04-16T11:51:36Z

Compiler of Arithmetic Expressions Using ANTLR

@@ Line 12: / Line 12: @@
 * <code>ADD, SUB, MUL, DIV, MOD</code> - it takes two values from the stack, computes the appropriate values, and stores the result on stack. If necessary, integers are automatically casted into floating-point numbers. <code>MOD</code> works only for integers.
 * <code>PUSH (I|F) n</code> - it stores the value <code>n</code> on stack. It will be either <code>int</code> or <code>float</code>.
 * <code>LOAD a</code> - it loads the value of variable <code>a</code> to the stack.
-* <code>SAVE a</code> - it takes the value from the stack and stores in into variable <code>a</code>.
+* <code>SAVE (I|F) a</code> - it takes the value from the stack, cast it into desired variable type (given as a second parameter I|F) and stores in into variable <code>a</code>. Again, the type of the variable <code>a</code> can be taken from symbol table from type checking.
 == Input specification ==

@@ Line 42: / Line 42: @@
 <syntaxhighlight lang="haskell" >
 PUSH I 0
-SAVE a
+SAVE I a
 PUSH I 0
-SAVE b
+SAVE I b
 PUSH I 15
-SAVE b
+SAVE I b
 LOAD b
-SAVE a
+SAVE I a
 LOAD a
 PRINT I
@@ Line 60: / Line 60: @@
 PRINT I
 PUSH F 0
-SAVE c
+SAVE F c
 LOAD a
 LOAD b
 ADD
-SAVE c
+SAVE F c
 LOAD c
 PRINT F
@@ Line 72: / Line 72: @@
 PRINT F
 LOAD a
-SAVE c
+SAVE F c
 LOAD c
 PRINT F

@@ Line 41: / Line 41: @@
 * Output
 <syntaxhighlight lang="haskell" >
 PUSH I 15
 SAVE b
@@ Line 55: / Line 59: @@
 MOD
 PRINT I
 LOAD a
 LOAD b

@@ Line 3: / Line 3: @@
 Extend the interpreter of arithmetic expressions from previous [[PLC_Laboratory_8 | Laboratory 8]]. In this laboratory, generate a stack-based target code defining the computation.
-The language description is still valid. Expressions contain +, -, *, /, % operators (with common priorities and left associativity) and parentheses. To simplify the task, consider we have only binary operators. There are no unary operators in our language. We have variables. Their identifiers compose from letters, and they have two types: <code>float</code> and <code>int</code>. Before variables are used, they need to be declared (use the same syntax as in C). The language is extended with <code>=</code> operator (lowest priority and right associativity).
+The language description is still valid. Expressions contain +, -, *, /, % operators (with common priorities and left associativity) and parentheses. To simplify the task, consider we have only binary operators. There are no unary operators in our language. We have variables. Their identifiers compose from letters, and they have two types: <code>float</code> and <code>int</code>. Before variables are used, they need to be declared (use the same syntax as in C). Initially, they have value 0. The language is extended with <code>=</code> operator (lowest priority and right associativity).
 Our expressions have a type. If it contains only integer numbers and variables its type is <code>int</code>. In all other cases it is <code>float</code>. In other words, if there is a floating-point number in our expression, all other integer values will be converted to float and the resulting type is <code>float</code>. In our language we also have a modulo: <code>%</code> that works only for integers.

@@ Line 3: / Line 3: @@
 Extend the interpreter of arithmetic expressions from previous [[PLC_Laboratory_8 | Laboratory 8]]. In this laboratory, generate a stack-based target code defining the computation.
-The language description is still valid. Expressions contain +, -, *, /, % operators (with common priorities and left associativity) and parentheses. To simplify the task, consider we have only binary operators. There are no unary operators in our language. We have variables. Their identifiers compose from letters and they have two types: <code>float</code> and <code>int</code>. Before variables are used, they need to be declared (use the same syntax as in C). The language is extended with <code>=</code> operator (lowest priority and right associativity).
+The language description is still valid. Expressions contain +, -, *, /, % operators (with common priorities and left associativity) and parentheses. To simplify the task, consider we have only binary operators. There are no unary operators in our language. We have variables. Their identifiers compose from letters, and they have two types: <code>float</code> and <code>int</code>. Before variables are used, they need to be declared (use the same syntax as in C). The language is extended with <code>=</code> operator (lowest priority and right associativity).
-Our expressions have a type. If it contains only integer numbers and variables its type is <code>int</code>. In all other cases it is <code>float</code>. In other words, if there is a floating point number in our expression, all other integer values will be converted to float and the resulting type is <code>float</code>. In our language we have also a modulo: <code>%</code> that works only for integers.
+Our expressions have a type. If it contains only integer numbers and variables its type is <code>int</code>. In all other cases it is <code>float</code>. In other words, if there is a floating-point number in our expression, all other integer values will be converted to float and the resulting type is <code>float</code>. In our language we also have a modulo: <code>%</code> that works only for integers.
 You can start with following C# codes from previous laboratory: [http://linedu.vsb.cz/~beh01/wiki_data/PLC_Lab9.zip PLC_Lab9.zip]
-The target stack-based code will constist of following instructions:
+The target stack-based code will consist of following instructions:
-* <code>ADD, SUB, MUL, DIV, MOD</code> - it takes two values from the stack, computes the apropriate value and stores the result on stack. If necessary, integers are automatically casted into floating-point numbers. <code>MOD</code> works only for integers.
+* <code>ADD, SUB, MUL, DIV, MOD</code> - it takes two values from the stack, computes the appropriate values, and stores the result on stack. If necessary, integers are automatically casted into floating-point numbers. <code>MOD</code> works only for integers.
 * <code>PUSH (I|F) n</code> - it stores the value <code>n</code> on stack. It will be either <code>int</code> or <code>float</code>.
 * <code>LOAD a</code> - it loads the value of variable <code>a</code> to the stack.

@@ Line 46: / Line 46: @@
 SAVE a
 LOAD a
-PRINT
+PRINT I
 LOAD a
 LOAD b
 ADD
-PRINT
+PRINT I
 LOAD a
 LOAD b
 MOD
-PRINT
+PRINT I
 LOAD a
 LOAD b
@@ Line 60: / Line 60: @@
 SAVE c
 LOAD c
-PRINT
+PRINT F
 LOAD c
 LOAD a
 ADD
-PRINT
+PRINT F
 LOAD a
 SAVE c
 LOAD c
-PRINT
+PRINT F
 LOAD c
 PUSH F 1.1
 ADD
-PRINT
+PRINT F
 PUSH I 10
 LOAD a
 MOD
-PRINT
+PRINT I
 </syntaxhighlight >

@@ Line 12: / Line 12: @@
 * <code>IADD, ISUB, IMUL, IDIV, FADD, FSUB, FMUL, FDIV, MOD</code> - it takes two values from the stack, computes the apropriate value and stores the result on stack. Variants starting with <code>I</code> computes with integer numbers, and instructions starting with <code>F</code> works with floating-point numbers. <code>MOD</code> works only for integers.
 * <code>PUSH (I|F) n</code> - it stores the value <code>n</code> on stack. It will either int or float.
 * <code>PRINT</code> - it takes a value from stack and prints it on output.