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Merged
gibson042 merged 1 commit into from
Sep 11, 2026
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Normative: Add initial spec text #5

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2 changes: 1 addition & 1 deletion package.json
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@
"license": "MIT",
"devDependencies": {
"@tc39/ecma262-biblio": "^2.1.2895",
"ecmarkup": "^21.3.0",
"ecmarkup": "^25.0.0",
"jsdom": "^26.1.0",
"parse5-html-rewriting-stream": "^7.1.0",
"tmp": "^0.2.3"
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233 changes: 203 additions & 30 deletions spec.emu
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@@ -1,39 +1,212 @@
<!doctype html>
<!DOCTYPE html>
<meta charset="utf8">
<link rel="stylesheet" href="./spec.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.4/styles/github.min.css">
<script src="./spec.js"></script>
<pre class="metadata">
title: Proposal Title Goes Here
stage: -1
contributors: Your Name(s) Here
title: Bigint from exponential
status: proposal
stage: 1
shortname: &lt;a href="https://github.com/tc39/proposal-bigint-from-exponential"&gt;proposal-bigint-from-exponential&lt;/a&gt;
contributors: Richard Gibson
</pre>
<style>
h1.shortname {
display: block;
}
</style>

<emu-clause id="sec-demo-clause">
<h1>This is an emu-clause</h1>
<p>This is an algorithm:</p>
<emu-alg>
1. Let _proposal_ be *undefined*.
1. If IsAccepted(_proposal_) is *true*, then
1. Let _stage_ be *0*<sub>ℤ</sub>.
1. Else,
1. Let _stage_ be *-1*<sub>ℤ</sub>.
1. Return ? ToString(_stage_).
</emu-alg>
</emu-clause>
<emu-clause id="sec-abstract-operations" number="7">
<h1>Abstract Operations</h1>

<emu-clause id="sec-type-conversion">
<h1>Type Conversion</h1>

<emu-clause id="sec-tonumber" oldids="table-tonumber-conversions" type="abstract operation" number="4">
<h1>
ToNumber (
_arg_: an ECMAScript language value,
): either a normal completion containing a Number or a throw completion
</h1>
<dl class="header">
<dt>description</dt>
<dd>It converts _arg_ to a value of type Number.</dd>
</dl>

<emu-clause id="sec-tonumber-applied-to-the-string-type">
<h1>ToNumber Applied to the String Type</h1>
<p>The abstract operation StringToNumber specifies how to convert a String value to a Number value, using the following grammar.</p>
<h2>Syntax</h2>
<emu-grammar type="definition">
StringNumericLiteral :::
StrWhiteSpace?
StrWhiteSpace? StrNumericLiteral StrWhiteSpace?

StrWhiteSpace :::
StrWhiteSpaceChar StrWhiteSpace?

StrWhiteSpaceChar :::
WhiteSpace
LineTerminator

StrNumericLiteral :::
StrDecimalLiteral
NonDecimalIntegerLiteral[~Sep]

StrDecimalLiteral :::
StrUnsignedDecimalLiteral
`+` StrUnsignedDecimalLiteral
`-` StrUnsignedDecimalLiteral

StrUnsignedDecimalLiteral :::
`Infinity`
DecimalDigits[~Sep] `.` DecimalDigits[~Sep]? ExponentPart[~Sep]?
`.` DecimalDigits[~Sep] ExponentPart[~Sep]?
DecimalDigits[~Sep] ExponentPart[~Sep]?
</emu-grammar>
<p>All grammar symbols not explicitly defined above have the definitions used in the Lexical Grammar for numeric literals (<emu-xref href="#sec-literals-numeric-literals"></emu-xref>)</p>
<emu-note>
<p>Some differences should be noted between the syntax of a |StringNumericLiteral| and a |NumericLiteral|:</p>
<ul>
<li>
A |StringNumericLiteral| may include leading and/or trailing white space and/or line terminators.
</li>
<li>
A |StringNumericLiteral| that is decimal may have any number of leading `0` digits.
</li>
<li>
A |StringNumericLiteral| that is decimal may include a `+` or `-` to indicate its sign.
</li>
<li>
A |StringNumericLiteral| that is empty or contains only white space is converted to *+0*<sub>𝔽</sub>.
</li>
<li>
`Infinity` and `-Infinity` are recognized as a |StringNumericLiteral| but not as a |NumericLiteral|.
</li>
<li>
A |StringNumericLiteral| cannot include a |BigIntLiteralSuffix|.
</li>
<li>
A |StringNumericLiteral| cannot include a |NumericLiteralSeparator|.
</li>
</ul>
</emu-note>

<emu-clause id="sec-stringtonumber" type="abstract operation">
<h1>
StringToNumber (
_string_: a String,
): a Number
</h1>
<dl class="header">
</dl>
<emu-alg>
1. Let _literal_ be ParseText(_string_, |StringNumericLiteral|).
1. If _literal_ is a List of errors, return *NaN*.
1. Return the StringNumericValue of _literal_.
</emu-alg>
</emu-clause>

<emu-clause id="sec-is-accepted" type="abstract operation">
<h1>
IsAccepted (
_proposal_: an ECMAScript language value
): a Boolean
</h1>
<dl class="header">
<dt>description</dt>
<dd>Tells you if the proposal was accepted</dd>
</dl>
<emu-alg>
1. If _proposal_ is not a String, or is not accepted, return *false*.
1. Return *true*.
</emu-alg>
<ins class="block">

<emu-clause id="sec-runtime-semantics-mv-for-stringnumericliteral">
<h1><ins>Runtime Semantics: MV</ins></h1>
<ul>
<li>
The MV of <emu-grammar>StringNumericLiteral ::: StrWhiteSpace?</emu-grammar> is 0.
</li>
<li>
The MV of <emu-grammar>StringNumericLiteral ::: StrWhiteSpace? StrNumericLiteral StrWhiteSpace?</emu-grammar> is the MV of |StrNumericLiteral|.
</li>
<li>
The MV of <emu-grammar>StrDecimalLiteral ::: `-` StrUnsignedDecimalLiteral</emu-grammar> is the negative of the MV of |StrUnsignedDecimalLiteral|.
</li>
<li>
The MV of <emu-grammar>StrUnsignedDecimalLiteral ::: `Infinity`</emu-grammar> is +∞.
</li>
<li>
The MV of <emu-grammar>StrUnsignedDecimalLiteral ::: DecimalDigits ExponentPart?</emu-grammar> is the MV of |DecimalDigits| × 10<sup>_e_</sup>, where _e_ is the MV of |ExponentPart| if |ExponentPart| is present and otherwise is 0.
</li>
<li>
The MV of <emu-grammar>StrUnsignedDecimalLiteral ::: `.` DecimalDigits ExponentPart?</emu-grammar> is the MV of |DecimalDigits| × 10<sup>_e_ - _n_</sup>, where _n_ is the number of code points in |DecimalDigits| and _e_ is the MV of |ExponentPart| if |ExponentPart| is present and otherwise is 0.
</li>
<li>
The MV of <emu-grammar>StrUnsignedDecimalLiteral ::: DecimalDigits `.` DecimalDigits? ExponentPart?</emu-grammar> is (the MV of the first |DecimalDigits| plus (_f_ × 10<sup>-_n_</sup>)) × 10<sup>_e_</sup>, where _f_ is the MV of the second |DecimalDigits| if the second |DecimalDigits| is present and otherwise is 0, _n_ is the number of code points in the second |DecimalDigits| if the second |DecimalDigits| is present and otherwise is 0, and _e_ is the MV of |ExponentPart| if |ExponentPart| is present and otherwise is 0.
</li>
</ul>
</emu-clause>
</ins>
</emu-clause>
</emu-clause>

<emu-clause id="sec-stringtobigint" type="abstract operation" number="16" oldids="sec-stringintegerliteral-grammar,prod-StringIntegerLiteral,prod-StrIntegerLiteral,sec-runtime-semantics-mv-for-stringintegerliteral">
<h1>
StringToBigInt (
_string_: a String,
): a BigInt or *undefined*
</h1>
<dl class="header">
</dl>
<emu-alg>
1. Let _literal_ be ParseText(_string_, <del>|StringIntegerLiteral|</del><ins>|StringNumericLiteral|</ins>).
1. If _literal_ is a List of errors, return *undefined*.
1. Let _mv_ be the MV of _literal_.
1. <del>Assert: _mv_ is an integer.</del>
1. <ins>If _mv_ is not an integer, return *undefined*.</ins>
1. Return ℤ(_mv_).
</emu-alg>

<del class="block">

<emu-clause id="sec-stringintegerliteral-grammar">
<h1><del>StringIntegerLiteral Grammar</del></h1>
<p>StringToBigInt uses the following grammar.</p>
<h2>Syntax</h2>
<emu-grammar type="definition">
StringIntegerLiteral :::
StrWhiteSpace?
StrWhiteSpace? StrIntegerLiteral StrWhiteSpace?

StrIntegerLiteral :::
SignedInteger[~Sep]
NonDecimalIntegerLiteral[~Sep]
</emu-grammar>
</emu-clause>
</del>

<del class="block">

<emu-clause id="sec-runtime-semantics-mv-for-stringintegerliteral">
<h1>Runtime Semantics: MV</h1>
<ul>
<li>
The MV of <emu-grammar>StringIntegerLiteral ::: StrWhiteSpace?</emu-grammar> is 0.
</li>
<li>
The MV of <emu-grammar>StringIntegerLiteral ::: StrWhiteSpace? StrIntegerLiteral StrWhiteSpace?</emu-grammar> is the MV of |StrIntegerLiteral|.
</li>
</ul>
</emu-clause>
</del>
</emu-clause>
</emu-clause>
</emu-clause>

<emu-annex id="sec-grammar-summary">
<h1>Grammar Summary</h1>

<emu-annex id="sec-number-conversions" number="6">
<h1>Number Conversions</h1>
<emu-prodref name="StringNumericLiteral"></emu-prodref>
<emu-prodref name="StrWhiteSpace"></emu-prodref>
<emu-prodref name="StrWhiteSpaceChar"></emu-prodref>
<emu-prodref name="StrNumericLiteral"></emu-prodref>
<emu-prodref name="StrDecimalLiteral"></emu-prodref>
<emu-prodref name="StrUnsignedDecimalLiteral"></emu-prodref>
<p>All grammar symbols not explicitly defined by the |StringNumericLiteral| grammar have the definitions used in the <emu-xref href="#sec-literals-numeric-literals">Lexical Grammar for numeric literals</emu-xref>.</p>
<del class="block">
<emu-prodref name="StringIntegerLiteral"></emu-prodref>
<emu-prodref name="StrIntegerLiteral"></emu-prodref>
</del>
</emu-annex>
</emu-annex>
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