Another grammar written.

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Shoofle 2013-08-06 12:15:24 -04:00
parent e85dc3c32e
commit dff49a1cce

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@ -122,4 +122,56 @@ number = contents:[0-9]+ { return parseInt(contents.join(""), 10); }
<code class="line">// So yeah</code>
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<p>I just keep writing grammars! Thanks, <a href="http://pegjs.majda.cz/online">pegjs!</a></p>
<pre><code class="language-grammar">
block = "{" contents:lines "}" { return contents; }
lines =
contents:(whitespace (branch / line) whitespace)*
{ var output = [];
for (var i=0; i&lt;contents.length; i++) { output.push(contents[i][1]); }
return output; }
branch =
main:if_branch elseifs:elseif_branch* elses:else_branch?
{ var output = [main];
if (elseifs.length &gt; 0) { output = output.concat(elseifs); }
if (elses) { output.push(elses); }
return output; }
if_branch = whitespace cond:if_line whitespace body:block
{ return {type: "if", condition: cond, consequent: body}; }
if_line = "if" whitespace "(" condition:line ")" { return condition; }
elseif_branch = whitespace cond:elseif_line whitespace body:block
{ return {type: "else if", condition: cond, consequent: body}; }
elseif_line = "else if" whitespace "(" condition:line ")" { return condition; }
else_branch = whitespace cond:else_line whitespace body:block
{ return {type: "else", condition: cond, consequent: body}; }
else_line = "else" { return "else"; }
line = start:word rest:(" "* word)*
{ var output = start;
for (var i=0; i&lt;rest.length; i++) { output += rest[i][0].join("") + rest[i][1]; }
return output; }
word = c:[A-Za-z]+ { return c.join(""); }
whitespace = (" " / "\n")*
</code></pre>
<p>Okay, and here's another lisp one, because they're so easy and satisfying:</p>
<pre><code class="language-grammar">
expression = whitespace e:(parenthetical / string_literal / number / identifier) whitespace
{ return e; }
parenthetical = "(" sequence:expression* ")" { return sequence; }
string_literal =
"'" characters:[^']* "'" { return characters.join(""); }
/ '"' characters:[^"]* '"' { return characters.join(""); }
number = digits:[0-9]+ { return parseInt(digits.join(""), 10); }
identifier = letters:[A-Za-z]+ { return letters.join(""); }
whitespace = [ \n\t]*
</code></pre>
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