From d5c7383231d3eaef5b0ab1ccb1a7fc6aa1cf1903 Mon Sep 17 00:00:00 2001
From: Victor Fernandes <victorvalenca@gmail.com>
Date: Fri, 10 Feb 2017 16:29:07 -0500
Subject: [PATCH] Rudimentary language specification

---
 PLATYPUS Grammar Specification.md | 171 ++++++++++++++++++++++++++++--
 1 file changed, 164 insertions(+), 7 deletions(-)

diff --git a/PLATYPUS Grammar Specification.md b/PLATYPUS Grammar Specification.md
index 4e9b778..ad9b3c7 100644
--- a/PLATYPUS Grammar Specification.md	
+++ b/PLATYPUS Grammar Specification.md	
@@ -1,10 +1,10 @@
 # PLATYPUS Language Specification
 
-## Lexical Specification (INCOMPLETE)
+## 2. Lexical Specification (INCOMPLETE)
 
 ## NOTE: **This is incredibly incomplete and broken, I am simply writing this down and will fix it as I read along the informal language specification provided to me**
 
-1. Input Elements and Tokens
+### 2.1 Input Elements and Tokens
 ```
     <input character> ->
         ASCII characters but not SEOF
@@ -19,7 +19,7 @@
         <variable identifier> | <keyword> | <floating-point literal>
         | <integer literal> | <string literal> | <separator> | <operator>
 ```
-2. White Space
+### 2.2 White Space
 ```
     <white space> ->
         ASCII SP character (space)
@@ -31,7 +31,7 @@
     <line terminator> ->
         CR | LF | CR LF
 ```
-3. Comments
+### 2.3 Comments
 ```
     <comment> ->
         !< <opt_characters in line> <line terminator>
@@ -42,7 +42,7 @@
     <comment character> ->
         <input character> but not <line terminator>
 ```
-4. Variable Identifiers
+### 2.4 Variable Identifiers
 ```
     <variable identifier> ->
         <arithmetic variable identifier> | <string variable identifier>
@@ -62,12 +62,12 @@
     <string variable identifier> ->
         <arithmetic variable identifier># 
 ```
-5. Keywords
+### 2.5 Keywords
 ```
     <keyword> ->
         PLATYPUS | IF | THEN | ELSE | USING | REPEAT | INPUT | OUTPUT
 ```
-6. Integer Literals
+### 2.6 Integer Literals
 ```
     <integer literal> ->
         <decimal integer literal> | <octal integer literal>
@@ -93,3 +93,160 @@
     <octal digits> ->
         <octal digit> | <octal digits> <octal digit>
     
+```
+### 2.7 Floating-point Literals
+```
+    <floating-point literal> ->
+        <decimal integer literal> . <opt_digits>
+```
+### 2.8 String Literals
+```
+    <string literal> ->
+        "<opt_string characters>"
+
+    <string chacters> ->
+        <input character> | <string characters> <input character>
+```
+### 2.9 Separators
+```
+    <separator> -> one of
+        ( ) { } , ; " .
+```
+### 2.10 Operators
+```
+    <operator> ->
+        <arithmetic operator> | <string concatenation operator>
+        | <relational operator> | <logical operator>
+        | <assignment operator>
+    
+    <arithmetic operator> -> one of
+        + - * /
+    
+    <string concatenation operator> -> one of
+        > < == <>
+
+    <logical operator> ->
+        .AND. | .OR.
+
+    <assignment operator> ->
+        =
+```
+## 3. The PLATYPUS Syntatic Specification
+### 3.1 PLATYPUS Program
+```
+    <program> ->
+        PLATYPUS {<opt_statements>} SEOF
+    
+    <statements> ->
+        <statement> | <statements> <statement>
+```
+### 3.2 Statements
+```
+    <statement> ->
+        <assignment statement>
+        | <selection statement>
+        | <iteration statement>
+        | <input statement>
+        | <output statement>
+```
+### 3.3 Assignment Statement
+```
+    <assignment statement> ->
+        <assignment expression>
+
+    <assignment expression> ->
+        AVID = <arithmetic expression>
+        | SVID = <string expression>
+```
+#### 3.2.2 Selection Statement (`if` statement)
+```
+    <selection statement> ->
+        IF (<conditional expression>) THEN <statements>
+        ELSE {<opt_statements>};
+```
+#### 3.2.3 Iteration Statement (the loop statement)
+```
+    <iteration statement> ->
+        <TBC>
+```
+#### 3.2.4 Input Statement
+```
+    <input statement> ->
+        INPUT (<variable list>);
+    
+    <variable list> ->
+        <variable identifier> | <variable list>,<variable identifier>
+```
+#### 3.2.5 Output Statement
+```
+    <output statement> ->
+        <TBC>
+```
+### 3.3 Expressions
+#### 3.3.1 Arithmetic Expressions
+```
+    <arithmetic expression> ->
+        <unary arithmetic expression>
+        | <additive arithmetic expression>
+
+    <unary arithmetic expression> ->
+        - <primary arithmetic expression>
+        | + <primary arithmetic expression
+
+    <additive arithmetic expression> ->
+        <additive arithmetic expression> + <multiplicative arithmetic expression>
+        | <additive arithmetic expression> - <multiplicative arithmetic expression>
+        | <multiplicative arithmetic expression>
+    
+    <multiplicative arithmetic expression> ->
+        <multiplicative arithmetic expression> * <primary arithmetic expression>
+        | <multiplicative arithmetic expression> / <primary arithmetic expression>
+        | <primary arithmetic expression>
+
+    <primary arithmetic expression> ->
+        <variable identifier>
+        | <floating-point literal>
+        | <integer literal>
+        | (<arithmetic expression>)
+```
+#### 3.3.2 String Expression
+```
+    <string expression> ->
+        <primary string expression>
+        | <string expression> << <primary string expression>
+
+    <primary string expression> ->
+        <string variable identifier>
+        | <string literal>
+```
+#### 3.3.3 Conditional Expression
+```
+    <conditional expression> ->
+        <logical OR expression>
+
+    <logical OR expression> ->
+        <TBC>
+
+    <logical AND expression> ->
+        <TBC>
+```
+#### 3.3.4 Relational Expression
+```
+    <relational expression> ->
+        <primary a_relational expression> == <primary a_relational expression>
+        | <primary a_relational expression> <= <primary a_relational expression>
+        | <primary a_relational expression> > <primary a_relational expression>
+        | <primary a_relational expression> < <primary a_relational expression>
+        | <primary s_relational expression> == <primary s_relational expression>
+        | <primary s_relational expression> <= <primary s_relational expression>
+        | <primary s_relational expression> > <primary s_relational expression>
+        | <primary s_relational expression> < <primary s_relational expression>
+    
+    <primary a_relational expression> ->
+        <floating-point literal>
+        | <integer literal>
+        | <variable identifier>
+
+    <primary s_relational expression> ->
+        <TBC>
+```
\ No newline at end of file