Remove schemas, add unread_keys.

I think that is all a schema was really needed for in the end,
since you can just check the types of things when
you are getting them.

1 files changed, 33 insertions, 233 deletions

diff --git a/site/spec.html b/site/spec.html
index 2e45352..481a32f 100644
--- a/site/spec.html
+++ b/site/spec.html
@@ -401,178 +401,6 @@ time = 35 min
 	be merged into the global configuration).
 </p>
 
-<h2>Schemas</h2>
-<p>
-	A <i>schema</i> is a POM file that describes how other POM files should be formatted
-	(i.e. what keys they should include, and what values they can be associated with).
-	A configuration can be said to <i>follow</i> a schema
-	when it obeys all of the schema’s rules.
-</p>
-<p>
-	POM’s schema format is not powerful to enforce all possible restrictions;
-	some will have to be enforced by the application.
-</p>
-<p>
-	Every schema key must be of the form <i>k</i><code>.</code><i>rule</i>, where
-	<i>k</i> is a valid key, and <i>rule</i> is one of the rule names listed below.
-</p>
-<p>
-	For any valid key <i>k</i> the value of the rule <i>rule</i> for <i>k</i> is determined as follows:
-</p>
-<ul>
-	<li>Break <i>k</i> down into its <i>n</i> components.</li>
-	<li>For each schema key <i>s</i>.<i>rule</i> where <i>s</i> has <i>n</i> components:
-		<ul>
-			<li>Match up the components of <i>s</i> with the components of <i>k</i>.</li>
-			<li>
-				If every component of <i>s</i> is equal to <code>*</code> or the corresponding component
-				of <i>k</i>, add <i>s</i>.<i>rule</i> to the <i>candidate-list</i>.
-			</li>
-	</ul></li>
-	<li>If the candidate-list is empty, use the default value for the rule.</li>
-	<li>If the candidate-list has exactly one schema key, use the value of that schema key.</li>
-	<li>
-		Otherwise select the schema key in the candidate-list with the
-		latest first <code>*</code>-component (in terms of component index),
-		preferring keys with no <code>*</code>,
-		breaking ties by the latest second <code>*</code>-component,
-		preferring keys with only one <code>*</code>, etc. Use its value.
-	</li>
-</ul>
-
-<h3>Example</h3>
-<p>
-Given the following schema:
-</p>
-<pre><code>
-*.*.id.type = Int
-vehicle.*.id.type = UInt
-*.truck.id.type = Float
-vehicle.car.id.type = String
-</code></pre>
-<p>
-The value of the <code>type</code> rule for vehicle.car.id is String,
-for vehicle.truck.id is UInt,
-for my.truck.id is Float,
-for my.car.id is Int,
-and for my.nephews.car.id is Any (no schema key matches, so the default is used).
-</p>
-
-<h3><code>type</code> rule</h3>
-<p>
-	Default: <code>Any</code>.
-</p>
-<p>
-	This describes what values a key is allowed to be associated with.
-	The following types are defined:
-</p>
-<ul>
-	<li><code>Any</code> or <code>String</code> — accepts any value</li>
-	<li><code>None</code> — accepts an unset value (special—see below)</li>
-	<li><code>Empty</code> — accepts an empty value (equivalent to <code>''</code>)</li>
-	<li>
-		<code>Bool</code> — accepts <code>true</code>, <code>on</code>, <code>yes</code>,
-		<code>false</code>, <code>off</code>, <code>no</code> (case- and white space- sensitive).
-	</li>
-	<li>
-		<code>UInt</code> — accepts any unsigned integer strictly less than 2<sup>53</sup>,
-		written in decimal or <code>0x</code> or <code>0X</code>-prefixed hexadecimal.
-		A leading <code>+</code> is permitted, but <code>-0</code> is not.
-		Leading zeroes are not permitted for decimal integers.
-		White space around the integer is not permitted.
-		Only 53 bits are allowed to support languages (JavaScript) with
-		a double type, but no 64-bit integer type.
-	</li>
-	<li>
-		<code>Int</code> — accepts any signed integer whose absolute value
-		is strictly less than 2<sup>53</sup>, written in decimal or
-		<code>0x</code> or <code>0X</code>-prefixed hexadecimal.
-		Leading zeroes are not permitted for decimal integers.
-		White space around the integer is not permitted.
-		A leading <code>+</code> (or, of course, <code>-</code>) is permitted.
-	</li>
-	<li>
-		<code>Float</code> — A floating-point number, written in ordinary decimal
-		(e.g. <code>-1.234</code>, <code>7.</code>, <code>265</code>) or in C-like scientific notation
-		(e.g. <code>3e5</code>, <code>3.E-5</code>, <code>-3.7e+005</code>).
-		Excessive leading zeroes are not permitted (<code>0.0</code> is allowed, but not <code>00.0</code>).
-		Values which overflow to ±∞ are allowed (e.g. <code>1e999</code>), but NaN and explicit
-		<code>inf</code>/<code>Infinity</code> are not.
-		White space around the number is not permitted.
-		The decimal point (if one is present) must be preceded and succeeded by digits.
-		A leading <code>+</code> (or, of course, <code>-</code>) is permitted.
-	<li>
-		<code>'</code><i>value</i><code>'</code> —
-		accepts the literal value <i>value</i>.
-		<i>value</i> cannot contain a literal apostrophe <code>'</code>.
-	</li>
-	<li>
-		<i>T</i><code> | </code><i>U</i>, where <i>T</i>, <i>U</i> are types
-		— accepts a value of type <i>T</i> or <i>U</i>.
-	</li>
-	<li>
-		<code>Optional[</code><i>T</i><code>]</code>, where <i>T</i> is a type
-		— equivalent to <i>T</i><code> | None</code>.
-	</li>
-	<li>
-		<code>List[</code><i>T</i><code>]</code>, where <i>T</i> is a type
-		— accepts a list of entries of type <i>T</i> (see description
-		of lists above). Nested lists are not permitted.
-	</li>
-</ul>
-<p>
-	A type may optionally have accepted-spaces on either side; this does not change its meaning.
-</p>
-
-<h3><code>allow_unknown</code> rule</h3>
-<p>
-		Default: inherited from parent (i.e. if <i>k</i> = <i>j</i><code>.</code><i>component</i>,
-		look up the <code>allow_unknown</code> rule for <i>j</i>),
-		or <code>yes</code> if <i>k</i> has no parent (does not contain a dot).
-</p>
-<p>
-	This describes whether or the key <i>k</i> is allowed if it is not described in the schema.
-	It must be set to either <code>yes</code> or <code>no</code>.
-</p>
-<p>
-	If a key is encountered in a configuration
-	and the value of its <code>allow_unknown</code> rule is <code>no</code>,
-	and it has no matching <code>type</code>, <code>maxlength</code>, or <code>default</code> rule,
-	the configuration does not follow the schema.
-</p>
-<h3><code>min</code>, <code>max</code> rules</h3>
-<p>
-	This schema key’s value must be a valid <code>Float</code> as described above.
-	It sets the minimum/maximum value for configuration keys’ values.
-	It only applies if the configuration key’s value
-	can be parsed as a <code>Float</code>.
-</p>
-<h3><code>maxlength</code> rule</h3>
-<p>
-	This schema key’s value must be a positive integer no greater than 2<sup>31</sup>−1,
-	written in decimal with no leading sign.
-	It specifies that the value of a key can be no longer than  that number of UTF-8 bytes.
-</p>
-<h3><code>default</code> rule</h3>
-<p>
-	Sets the default value for a key.
-</p>
-<h3>Missing values</h3>
-<p>
-	If there is a schema key <i>k</i><code>.type</code>, where <i>k</i>
-	does not contain any <code>*</code>-components,
-	and the type does not allow unset values (<code>None</code>),
-	and there is no schema key <i>k</i><code>.default</code>,
-	then a configuration must contain the key <i>k</i> to follow the schema.
-</p>
-<p>
-	Additionally, if there is a schema key <i>j</i><code>.*.</code><i>k</i><code>.type</code>
-	that does not allow unset values and no correspoding <code>default</code> schema key,
-	where <i>k</i> does not contain any <code>*</code>-components, then a configuration
-	containing a key <i>x</i> matching <i>j</i><code>.*</code> must also contain
-	the key <i>x</i><code>.</code><i>k</i>.
-</p>
-
 <h2>Extensions</h2>
 <p>
 	If needed for a particular domain, an parser may accept an extended form of the POM syntax.
@@ -624,8 +452,7 @@ and for my.nephews.car.id is Any (no schema key matches, so the default is used)
 	<li>
 		<code>location(conf: Configuration, key: String) -&gt; Optional&lt;Location&gt;</code><br>
 		Location of the definition of <code>key</code> in the configuration (file and line number).
-		Useful for reporting invalid values when
-		the format of valid values can’t be described by a schema type.
+		Useful for reporting invalid values.
 		If a key <i>k</i> isn’t given a value in the configuration, but a key of the form
 		<i>k</i><code>.</code><i>j</i> is, then the
 		location of the definition of an arbitrary such key
@@ -643,27 +470,44 @@ and for my.nephews.car.id is Any (no schema key matches, so the default is used)
 		<code>get_int(conf: Configuration, key: String) -&gt; Optional&lt;Int&gt;</code><br>
 		<code>get_int_or_default(conf: Configuration, key: String, default: Int) -&gt; Int</code><br>
 		Get value associated with <code>key</code>,
-		if any exists, and parse it as a signed integer,
-		following the <code>Int</code> schema type described above
+		if any exists, and parse it as a signed integer
 		(returning <code>default</code> if the key doesn’t exist).
-		Returns an error if the key exists but its value is not a valid signed 64-bit integer.
+		The integer’s absolute value must be strictly less than 2<sup>53</sup>,
+		written in decimal or
+		<code>0x</code>/<code>0X</code>-prefixed hexadecimal.
+		Leading zeroes are not permitted for decimal integers.
+		White space around or within the integer is not permitted.
+		A leading <code>+</code> (or, of course, <code>-</code>) is permitted.
+		If the key exists but its value does not follow these rules, an error is returned.
 	</li>
 	<li>
 		<code>get_uint(conf: Configuration, key: String) -&gt; Optional&lt;UInt&gt;</code><br>
 		<code>get_uint_or_default(conf: Configuration, key: String, default: UInt) -&gt; UInt</code><br>
 		Get value associated with <code>key</code>, if any exists,
-		and parse it as an unsigned integer,
-		following the <code>UInt</code> schema type described above
+		and parse it as an unsigned integer
 		(returning <code>default</code> if the key doesn’t exist).
-		Returns an error if the key exists but its value is not a valid unsigned 63-bit integer.
+		The integer must be at least 0 and strictly less than 2<sup>53</sup>,
+		written in decimal or <code>0x</code> or <code>0X</code>-prefixed hexadecimal.
+		A leading <code>+</code> is permitted, but <code>-0</code> is not.
+		Leading zeroes are not permitted for decimal integers.
+		White space around or within the integer is not permitted.
+		If the key exists but its value does not follow these rules, an error is returned.
 	</li>
 	<li>
 		<code>get_float(conf: Configuration, key: String) -&gt; Optional&lt;Float&gt;</code><br>
 		<code>get_float_or_default(conf: Configuration, key: String, default: Float) -&gt; Float</code><br>
 		Get value associated with <code>key</code>, if any exists,
 		and parse it as a 64-bit IEEE-754 double precision
-		floating-point number, following the <code>Float</code> schema type described above
-		(returning <code>default</code> if the key doesn’t exist).
+		floating-point number (returning <code>default</code> if the key doesn’t exist).
+		The number must be written in ordinary decimal
+		(e.g. <code>-1.234</code>, <code>7.</code>, <code>265</code>) or in C-like scientific notation
+		(e.g. <code>3e5</code>, <code>3.E-5</code>, <code>-3.7e+005</code>).
+		Excessive leading zeroes are not permitted (<code>0.0</code> is allowed, but not <code>00.0</code>).
+		Values which overflow to ±∞ are allowed (e.g. <code>1e999</code>), but NaN and explicit
+		<code>inf</code>/<code>Infinity</code> are not.
+		White space around or within the number is not permitted.
+		The decimal point (if one is present) must be preceded and succeeded by digits.
+		A leading <code>+</code> (or, of course, <code>-</code>) is permitted.
 		Returns an error if the key exists but its value is not a valid floating-point number.
 	</li>
 	<li>
@@ -692,14 +536,13 @@ and for my.nephews.car.id is Any (no schema key matches, so the default is used)
 		Returns the result of merging <code>conf_b</code> into <code>conf_a</code>.
 	</li>
 	<li>
-		<code>parse_schema(conf: Configuration) -&gt; Schema</code> (<i>optional</i>)<br>
-		Parse <code>conf</code> as a schema, returning an error if it is invalid.
-	</li>
-	<li>
-		<code>check_against_schema(conf: Configuration, schema: Schema) -&gt; Configuration</code> (<i>optional</i>)<br>
-		Check <code>conf</code> follows <code>schema</code>,
-		returning an error with detailed information
-		if not. If successful, returns a configuration with default values filled out.
+		<code>unread_keys(conf: Configuration) -&gt; List&lt;String&gt;</code><br>
+		Returns a list of all keys which have not been the target of a <code>get</code> / <code>get_*</code>
+		call, either directly or through a section obtained from the <code>section</code> function,
+		in an arbitrary order.
+		When configurations are merged, the gotten-ness of the values is preserved.
+		Whether or not getting values from the merged configuration affects the original configurations’
+		gotten-nesses is unspecified (and should rarely matter).
 	</li>
 </ul>
 
@@ -806,49 +649,6 @@ This configuration has the following mapping of keys to values:
 	</tbody>
 </table>
 
-<h3>Schema for text editor’s configuration</h3>
-<p>
-	Here is a schema which a text editor might use.
-	The example text editor configuration above follows it.
-</p>
-<pre><code>
-# don't allow unknown keys by default
-*.allow_unknown = no
-
-# must put this in your config! I can't make the decision for you!
-indentation-type.type = 'spaces' | 'tabs'
-
-show-line-numbers.type = Bool
-show-line-numbers.default = on
-
-[tab-size]
-type = UInt
-min = 1
-default = 4
-
-[font-size]
-# allow fractional font sizes; why not!
-type = Float
-min = 0.5
-max = 100
-default = 14
-
-[plug-in.*]
-enabled.type = Bool
-enabled.default = yes
-path.type = String
-# everyone be nice to the Microsoft Windows®
-path.maxlength = 260
-# allow arbitrary keys in plug-ins' settings
-settings.allow_unknown = yes
-
-[file-extensions]
-*.type = List[String]
-C.default = .c, .h
-Cpp.default = .cpp, .hpp, .cc, .hh
-C-sharp.default = .cs
-</code></pre>
-
 <h3>Errors</h3>
 <p>
 This section lists some erroneous lines that might appear in a POM file: