The grammar is simple and regular, allowing for easy analysis by automatic tools such as integrated development environments.
</p>
+<h2>Notation</h2>
+
+<p>
+The syntax is specified using Extended Backus-Naur Form (EBNF):
+</p>
+
+<pre>
+Production = production_name "=" Expression .
+Expression = Alternative { "|" Alternative } .
+Alternative = Term { Term } .
+Term = production_name | token [ "..." token ] | Group | Option | Repetition .
+Group = "(" Expression ")" .
+Option = "[" Expression ")" .
+Repetition = "{" Expression "}" .
+</pre>
+
+<p>
+Productions are expressions constructed from terms and the following operators, in increasing precedence:
+</p>
+<pre>
+| alternation
+() grouping
+[] option (0 or 1 times)
+{} repetition (0 to n times)
+</pre>
+
+<p>
+Lower-case production names are used to identify lexical tokens. Non-terminals are in CamelCase. Lexical symbols are enclosed in double quotes <tt>""</tt> (the
+double quote symbol is written as <tt>'"'</tt>).
+</p>
+
+<p>
+The form <tt>"a ... b"</tt> represents the set of characters from <tt>a</tt> through <tt>b</tt> as alternatives.
+</p>
+
+<p>
+Where possible, recursive productions are used to express evaluation order
+and operator precedence syntactically.
+</p>
+
+
<h2>Lexical properties</h2>
<p>
<h3>Identifiers</h3>
<p>
-An identifier is a sequence of one or more letters and digits. The meaning of <i>letter</i> and <i>digit</i> is defined by the Unicode properties for the corresponding characters, with the addition that the underscore character <tt>_</tt> (U+005F) is considered a letter. The first character in an identifier must be a letter. <font color=red>(Current implementation accepts only ASCII digits for digits.)</font>
+An identifier is a sequence of one or more letters and digits. The meaning of <i>letter</i> and <i>digit</i> is defined by the Unicode properties for the corresponding characters, with the addition that the underscore character <tt>_</tt> (U+005F) is considered a letter. The first character in an identifier must be a letter.
</p>
+<pre>
+letter = unicode_letter | "_" .
+identifier = letter { letter | unicode_digit } .
+</pre>
+
<h3>Keywords</h3>
<p>
<h4>Integer literals</h4>
+<p>
+An integer literal is a sequence of one or more digits in the corresponding base, which may be 8, 10, or 16. An optional prefix sets a non-decimal base: <tt>0</tt> for octal, <tt>0x</tt> or <tt>0X</tt> for hexadecimal. In hexadecimal literals, letters <tt>a-f</tt> and <tt>A-F</tt> represent values 10 through 15.
+</p>
+<pre>
+int_lit = decimal_lit | octal_lit | hex_lit .
+decimal_lit = ( "1" ... "9" ) { decimal_digit } .
+octal_lit = "0" { octal_digit } .
+hex_lit = "0" ( "x" | "X" ) hex_digit { hex_digit } .
+decimal_digit = "0" ... "9" .
+octal_digit = "0" ... "7" .
+hex_digit = "0" ... "9" | "A" ... "F" | "a" ... "f" .
+</pre>
+
+<p>
+Integer literals represent values of arbitrary precision, or <i>ideal integers</i>; they have no implicit size or type.
+</p>
+
<h4>Floating-point literals</h4>
+<p>
+A floating-point literal is a decimal representation of a floating-point number. It has an integer part, a decimal point, a fractional part, and an exponent part. The integer and fractional part comprise decimal digits; the exponent part is an <tt>e</TT> or <tt>E</tt> followed by an optionally signed decimal exponent. One of the integer part or the fractional part may be elided; one of the decimal point or the exponent may be elided.
+</p>
+<pre>
+float_lit = decimals "." [ decimals ] [ exponent ] |
+ decimals exponent |
+ "." decimals [ exponent ] .
+decimals = decimal_digit { decimal_digit } .
+exponent = ( "e" | "E" ) [ "+" | "-" ] decimals .
+</pre>
+
+<p>
+As with integers, floating-point literals represent values of arbitrary precision, or <i>ideal floats</i>.
+</p>
<h4>Character literals</h4>
+<p>
+A character literal represents an integer value, typically a Unicode code point, as one or more characters enclosed in single quotes. Within the quotes, any character may appear except single quote and newline; a quoted single character represents itself, while multi-character sequences beginning with a backslash encode values in various formats.
+</p>
+<p>
+The simplest form represents the exact character within the quotes; since Go source text is Unicode characters encoded in UTF-8, multiple UTF-8-encoded bytes may represent a single integer value. For instance, the literal <tt>'a'</tt> holds a single byte representing a literal <tt>a</tt>, Unicode U+0061, value <tt>0x61</tt>, while <tt>'ä'</tt> holds two bytes (<tt>0xc3</tt> <tt>0xa4</tt>) representing a literal <tt>a</tt>-dieresis, U+00E4, value <tt>0xe4</tt>.
+</p>
+<p>
+Several backslash escapes allow arbitrary values to be represented as ASCII text. There are four ways to represent the integer value as a numeric constant: <tt>\x</tt> followed by exactly two hexadecimal digits; <tt>\u</tt> followed by exactly four hexadecimal digits; <tt>\U</tt> followed by exactly eight hexadecimal digits, and a plain backslash <tt>\</tt> followed by exactly three octal digits. In each case the value of the literal is the value represented by the digits in the appropriate base.
+</p>
+<p>
+Although these representations all result in an integer, they have different valid ranges. Octal escapes must represent a value between 0 and 255 inclusive. (Hexadecimal escapes satisfy this condition by construction). The `Unicode' escapes <tt>\u</tt> and <tt>\U</tt> represent Unicode code points so within them some values are illegal, in particular those above <tt>0x10FFFF</tt> and surrogate halves.
+</p>
+<p>
+After a backslash, certain single-character escapes represent special values:
+</p>
+<pre>
+\a U+0007 alert or bell
+\b U+0008 backspace
+\f U+000C form feed
+\n U+000A line feed or newline
+\r U+000D carriage return
+\t U+0009 horizontal tab
+\v U+000b vertical tab
+\\ U+005c backslash
+\' U+0027 single quote (legal within character literals only)
+\" U+0022 double quote (legal within interpreted string literals only)
+</pre>
+<p>
+All other sequences are illegal inside character literals.
+</p>
+<pre>
+char_lit = "'" ( unicode_value | byte_value ) "'" .
+unicode_value = unicode_char | little_u_value | big_u_value | escaped_char .
+byte_value = octal_byte_value | hex_byte_value .
+octal_byte_value = "\" octal_digit octal_digit octal_digit .
+hex_byte_value = "\" "x" hex_digit hex_digit .
+little_u_value = "\" "u" hex_digit hex_digit hex_digit hex_digit .
+big_u_value = "\" "U" hex_digit hex_digit hex_digit hex_digit
+ hex_digit hex_digit hex_digit hex_digit .
+escaped_char = "\" ( "a" | "b" | "f" | "n" | "r" | "t" | "v" | "\" | "'" | """ ) .
+</pre>
+
+<p>
+The value of a character literal is an ideal integer, just as with integer literals.
+</p>
+
<h4>String literals</h4>
+<p>
+String literals represent constant values of type <tt>string</tt>. There are two forms: raw string literals and interpreted string literals.
+</p>
+<p>
+Raw string literals are character sequences between back quotes <tt>``</tt>. Within the quotes, any character is legal except newline and back quote. The value of a raw string literal is the string composed of the uninterpreted bytes between the quotes.
+</p>
+<p>
+Interpreted string literals are character sequences between double quotes <tt>""</tt>. The text between the quotes forms the value of the literal, with backslash escapes interpreted as they are in character literals. The three-digit octal (<tt>\000</tt>) and two-digit hexadecimal (<tt>\x00</tt>) escapes represent individual <i>bytes</i> of the resulting string; all other escapes represent the (possibly multi-byte) UTF-8 encoding of individual <i>characters</i>. Thus inside a string literal <tt>\377</tt> and <tt>\xFF</tt> represent a single byte of value <tt>0xFF</tt>=255, while <tt>ÿ</tt>, <tt>\u00FF</tt>, <tt>\U000000FF</tt> and <tt>\xc3\xbf</tt> represent the two bytes <tt>0xc3 0xbf</tt> of the UTF-8 encoding of character U+00FF.
+</p>
+<pre>
+string_lit = raw_string_lit | interpreted_string_lit .
+raw_string_lit = "`" { unicode_char } "`" .
+interpreted_string_lit = """ { unicode_value | byte_value } """ .
+</pre>
+
+<p>
+During tokenization, two adjacent string literals separated only by the empty string, white space, or comments are implicitly combined into a single string literal whose value is the concatenated values of the literals.
+</p>
+<pre>
+StringLit = string_lit { string_lit } .
+</pre>
+
+<h2>Everything else</h2>
+
+<p>
+I don't believe this organization is complete or correct but it's here to be worked on and thought about.
+</p>
+
+<h2>Types</h2>
+
+<h2>Constants</h2>
+
+<h2>Expressions</h2>
+
+<h2>Declarations</h2>
+
+<h2>Control Structures</h2>
+
+<h2>Program structure</h2>
+
+<h2>Packages</h2>
+
+<h2>Differences between this doc and implementation - TODO</h2>
+<p>
+<font color=red>
+Current implementation accepts only ASCII digits for digits; doc says Unicode.
+<br>
+</font>
+</p>
</div>
<br class="clearboth" />