coregrammars 0.4.0

coregrammars

A collection of basic grammars in D / pegged compiled as modules.

Each grammar is contained in a submodule, so to include the ini grammar for example, add coregrammars:ini to your dependencies.

There are also a collection of parsers that convert grammar tree nodes into tuples at compile time.

And, there are utilities that can also process files at runtime into a Variant[string] reference. This can be used to update field values a tuple parsed at compile time.

To use the grammars:

import coregrammars.gen.json;

enum input = `
{
"Number": 42,
"Decimal": 123.456,
"String": "abc",
"NullString": "",
"Escape": "\uAAAA\n\\Hello",
"Array" : [0,1,2],
"Array2": [0, [0,1,2], "abc"],
"Obj"   : { "Member":0, "Member":[0,1,2] },
"True"  : true,
"False" : false,
"Null"  : null,
"Empty" : {}
}`;

enum nodes = JSONGrammar(input);

assert(nodes[0][0][0].matches == ["Number"]);
assert(nodes[0][0][1].matches == ["42"]);

And so on for the other grammars.

Here is the list of grammars:

• Terminals: basic terminal expressions such as strings, numbers and booleans.
• Expressions: arithmetic expressions.
• INI: standard INI file syntax
• JSON: standard JSON syntax
• Markdown: standard markdown syntax

These exist as .peg files in the resources folder.

To regenerate the modules from .peg files, run:

dub test -c modgen && dub run -c modgen && dub test

To use the parsers:

    import coregrammars.gen.ini;
    import coregrammars.parsers.ini;

	enum Nodes = INIGrammar(q{
[TestSect]
testKey = "test value"
testKey2 = "test value"
testBool = false

[TestSect.A]
testKeyA = "test value A"
testKeyA2 = "test value B"
testInt = 10

[TestSect.B]
testKeyB = "test value B"
#testDouble = 54.321

[TestSect2]
testKey = "test value 2"

[TestSect2.A]
testKeyA = "test value 2 A"
testIntA = 22

[TestSect3]
testKey = "test value"

    });
	enum x = parse_node!Nodes;
	
	//writeln(x);
	
	static assert(x.TestSect.A.testKeyA2 == "test value B");
	static assert(x.TestSect.testBool == false);
	static assert(x.TestSect2.A.testIntA == 22);

  import coregrammars.gen.json;
  import coregrammars.parsers.json;
  alias JSON=JSONGrammar;
    enum example2 = `
    {
    "Number": 42,
    "Decimal": 123.456,
    "String": "abc",
    "NullString": "",
    "Escape": "\uAAAA\n\\Hello",
    "Array" : [0,1,2],
    "Array2": [0, [0,1,2], "abc"],
    "Obj"   : { "Member":0, "Member2":[0,1,2] },
    "True"  : true,
    "False" : false,
    "Null"  : null,
    "Empty" : {}
    }`;

    enum example2Tree = JSON(example2);
    enum x = parse_node!example2Tree;

    static assert(x.Number == 42);
    static assert(x.Array[2] == 2);
    static assert(x.Array2[1][1] == 1);
    static assert(x.Obj.Member2[2] == 2);

To load an ini file into an array Variant[string] at runtime

	auto txt = readText("./resources/tests/testB.ini");
	auto nodes = INIGrammar(txt);
	Variant[string] vals;
	parse_node(vals,nodes);

	assert(vals["TestSect"]["A"]["testKeyA2"] == "test value B ***");

Load a file at runtime and override the values in a tuple created at compile time:

    enum Nodes = INIGrammar(import("tests/test.ini"));
	auto nodesTuple = parse_node!Nodes;

	auto txt = readText("./resources/tests/testB.ini");
	auto nodes = INIGrammar(txt);
	Variant[string] vals;
	parse_node(vals,nodes);
	set_fields!(typeof(nodesTuple))(nodesTuple,vals);

	assert(nodesTuple.TestSect.A.testKeyA2 == "test value B ***");

TODO

The terminals grammar is losing the type information for Terminals.Number nodes. At this time all numbers are processed into doubles, however it should be simple to implement int as well.