Modules¶
Indices¶
Indices can be given either in raw numeric form or as symbolic identifiers when bound by a respective construct. Such identifiers are looked up in the suitable space of the identifier context \(I\).
\[\begin{split}\begin{array}{llcllllllll}
\def\mathdef3854#1{{}}\mathdef3854{type index} & \href{../text/modules.html#text-typeidx}{\mathtt{typeidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{types}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{function index} & \href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{funcs}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{table index} & \href{../text/modules.html#text-tableidx}{\mathtt{tableidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{tables}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{memory index} & \href{../text/modules.html#text-memidx}{\mathtt{memidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{mems}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{global index} & \href{../text/modules.html#text-globalidx}{\mathtt{globalidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{globals}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{tag index} & \href{../text/modules.html#text-tagidx}{\mathtt{tagidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{tags}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{element index} & \href{../text/modules.html#text-elemidx}{\mathtt{elemidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{elem}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{data index} & \href{../text/modules.html#text-dataidx}{\mathtt{dataidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{data}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{local index} & \href{../text/modules.html#text-localidx}{\mathtt{localidx}}_I &::=&
x{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& x \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& x & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{locals}}[x] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{label index} & \href{../text/modules.html#text-labelidx}{\mathtt{labelidx}}_I &::=&
l{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& l \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& l & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{labels}}[l] = v) \\
\def\mathdef3854#1{{}}\mathdef3854{field index} & \href{../text/modules.html#text-fieldidx}{\mathtt{fieldidx}}_{I,x} &::=&
i{:}\href{../text/values.html#text-int}{\def\mathdef3879#1{{\mathtt{u}#1}}\mathdef3879{\mathtt{32}}} &\Rightarrow& i \\&&|&
v{:}\href{../text/values.html#text-id}{\mathtt{id}} &\Rightarrow& i & (\mathrel{\mbox{if}} I.\href{../text/conventions.html#text-context}{\mathsf{fields}}[x][i] = v) \\
\end{array}\end{split}\]
Type Uses¶
A type use is a reference to a function type definition. It may optionally be augmented by explicit inlined parameter and result declarations. That allows binding symbolic identifiers to name the local indices of parameters. If inline declarations are given, then their types must match the referenced function type.
\[\begin{split}\begin{array}{llcllll}
\def\mathdef3854#1{{}}\mathdef3854{type use} & \href{../text/modules.html#text-typeuse}{\mathtt{typeuse}}_I &::=&
\def\mathdef3893#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3893{(}~\def\mathdef3894#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3894{type}~~x{:}\href{../text/modules.html#text-typeidx}{\mathtt{typeidx}}_I~\def\mathdef3895#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3895{)}
\quad\Rightarrow\quad x, I' \\ &&& \qquad
(\mathrel{\mbox{if}} \begin{array}[t]{@{}l@{}}
I.\href{../text/conventions.html#text-context}{\mathsf{typedefs}}[x] = \href{../syntax/types.html#syntax-subtype}{\mathsf{sub}}~\href{../syntax/types.html#syntax-subtype}{\mathsf{final}}~(\href{../syntax/types.html#syntax-comptype}{\mathsf{func}}~[t_1^n] \href{../syntax/types.html#syntax-functype}{\rightarrow} [t_2^\ast]) \wedge
I' = \{\href{../text/conventions.html#text-context}{\mathsf{locals}}~(\epsilon)^n\}) \\
\end{array} \\[1ex] &&|&
\def\mathdef3896#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3896{(}~\def\mathdef3897#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3897{type}~~x{:}\href{../text/modules.html#text-typeidx}{\mathtt{typeidx}}_I~\def\mathdef3898#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3898{)}
~~(t_1{:}\href{../text/types.html#text-functype}{\mathtt{param}})^\ast~~(t_2{:}\href{../text/types.html#text-functype}{\mathtt{result}})^\ast
\quad\Rightarrow\quad x, I' \\ &&& \qquad
(\mathrel{\mbox{if}} \begin{array}[t]{@{}l@{}}
I.\href{../text/conventions.html#text-context}{\mathsf{typedefs}}[x] = \href{../syntax/types.html#syntax-subtype}{\mathsf{sub}}~\href{../syntax/types.html#syntax-subtype}{\mathsf{final}}~(\href{../syntax/types.html#syntax-comptype}{\mathsf{func}}~[t_1^\ast] \href{../syntax/types.html#syntax-functype}{\rightarrow} [t_2^\ast]) \wedge
I' = \{\href{../text/conventions.html#text-context}{\mathsf{locals}}~\mathrm{id}(\href{../text/types.html#text-functype}{\mathtt{param}})^\ast\} ~\href{../text/conventions.html#text-context-wf}{\mbox{well-formed}}) \\
\end{array} \\
\end{array}\end{split}\]
Note
If inline declarations are given, their types must be syntactically equal to the types from the indexed definition; possible type substitutions from other definitions that might make them equal are not taken into account. This is to simplify syntactic pre-processing.
The synthesized attribute of a \(\href{../text/modules.html#text-typeuse}{\mathtt{typeuse}}\) is a pair consisting of both the used type index and the local identifier context containing possible parameter identifiers. The following auxiliary function extracts optional identifiers from parameters:
\[\begin{split}\begin{array}{lcl@{\qquad\qquad}l}
\mathrm{id}(\def\mathdef3899#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3899{(}~\def\mathdef3900#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3900{param}~\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef3901#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3901{)}) &=& \href{../text/values.html#text-id}{\mathtt{id}}^? \\
\end{array}\end{split}\]
Note
Both productions overlap for the case that the function type is \([] \href{../syntax/types.html#syntax-functype}{\rightarrow} []\). However, in that case, they also produce the same results, so that the choice is immaterial.
The well-formedness condition on \(I'\) ensures that the parameters do not contain duplicate identifiers.
Abbreviations¶
A \(\href{../text/modules.html#text-typeuse}{\mathtt{typeuse}}\) may also be replaced entirely by inline parameter and result declarations. In that case, a type index is automatically inserted:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{type use} &
(t_1{:}\href{../text/types.html#text-functype}{\mathtt{param}})^\ast~~(t_2{:}\href{../text/types.html#text-functype}{\mathtt{result}})^\ast &\equiv&
\def\mathdef3902#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3902{(}~\def\mathdef3903#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3903{type}~~x~\def\mathdef3904#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3904{)}~~\href{../text/types.html#text-functype}{\mathtt{param}}^\ast~~\href{../text/types.html#text-functype}{\mathtt{result}}^\ast \\
\end{array}\end{split}\]
where \(x\) is the smallest existing type index whose recursive type definition in the current module is of the form
\[\def\mathdef3905#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3905{(}~\def\mathdef3906#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3906{rec}~\def\mathdef3907#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3907{(}~\def\mathdef3908#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3908{type}~\def\mathdef3909#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3909{(}~\def\mathdef3910#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3910{sub}~\def\mathdef3911#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3911{final}~~\def\mathdef3912#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3912{(}~\def\mathdef3913#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3913{func}~~\href{../text/types.html#text-functype}{\mathtt{param}}^\ast~~\href{../text/types.html#text-functype}{\mathtt{result}}^\ast~\def\mathdef3914#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3914{)}~\def\mathdef3915#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3915{)}~\def\mathdef3916#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3916{)}~\def\mathdef3917#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3917{)}\]
If no such index exists, then a new recursive type of the same form is inserted at the end of the module.
Abbreviations are expanded in the order they appear, such that previously inserted type definitions are reused by consecutive expansions.
Imports¶
The descriptors in imports can bind a symbolic function, table, memory, tag, or global identifier.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{import} & \href{../text/modules.html#text-import}{\mathtt{import}}_I &::=&
\def\mathdef3918#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3918{(}~\def\mathdef3919#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3919{import}~~\mathit{mod}{:}\href{../text/values.html#text-name}{\mathtt{name}}~~\mathit{nm}{:}\href{../text/values.html#text-name}{\mathtt{name}}~~d{:}\href{../text/modules.html#text-importdesc}{\mathtt{importdesc}}_I~\def\mathdef3920#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3920{)} \\ &&& \qquad
\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-import}{\mathsf{module}}~\mathit{mod}, \href{../syntax/modules.html#syntax-import}{\mathsf{name}}~\mathit{nm}, \href{../syntax/modules.html#syntax-import}{\mathsf{desc}}~d \} \\[1ex]
\def\mathdef3854#1{{}}\mathdef3854{import description} & \href{../text/modules.html#text-importdesc}{\mathtt{importdesc}}_I &::=&
\def\mathdef3921#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3921{(}~\def\mathdef3922#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3922{func}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~x,I'{:}\href{../text/modules.html#text-typeuse}{\mathtt{typeuse}}_I~\def\mathdef3923#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3923{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-importdesc}{\mathsf{func}}~x \\ &&|&
\def\mathdef3924#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3924{(}~\def\mathdef3925#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3925{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\mathit{tt}{:}\href{../text/types.html#text-tabletype}{\mathtt{tabletype}}_I~\def\mathdef3926#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3926{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-importdesc}{\mathsf{table}}~\mathit{tt} \\ &&|&
\def\mathdef3927#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3927{(}~\def\mathdef3928#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3928{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\mathit{mt}{:}\href{../text/types.html#text-memtype}{\mathtt{memtype}}_I~\def\mathdef3929#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3929{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-importdesc}{\mathsf{mem}}~~\mathit{mt} \\ &&|&
\def\mathdef3930#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3930{(}~\def\mathdef3931#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3931{global}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\mathit{gt}{:}\href{../text/types.html#text-globaltype}{\mathtt{globaltype}}_I~\def\mathdef3932#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3932{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-importdesc}{\mathsf{global}}~\mathit{gt} \\ &&|&
\def\mathdef3933#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3933{(}~\def\mathdef3934#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3934{tag}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\mathit{tt}{:}\href{../text/modules.html#text-tag}{\mathtt{tag}}~\def\mathdef3935#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3935{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-importdesc}{\mathsf{tag}}~\mathit{tt} \\
\end{array}\end{split}\]
Abbreviations¶
As an abbreviation, imports may also be specified inline with function, table, memory, global, or tag definitions; see the respective sections.
Functions¶
Function definitions can bind a symbolic function identifier, and local identifiers for its parameters and locals.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{function} & \href{../text/modules.html#text-func}{\mathtt{func}}_I &::=&
\def\mathdef3936#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3936{(}~\def\mathdef3937#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3937{func}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~x,I'{:}\href{../text/modules.html#text-typeuse}{\mathtt{typeuse}}_I~~
(\mathit{loc}{:}\href{../text/modules.html#text-local}{\mathtt{local}}_I)^\ast~~(\mathit{in}{:}\href{../text/instructions.html#text-instr}{\mathtt{instr}}_{I''})^\ast~\def\mathdef3938#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3938{)} \\ &&& \qquad
\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-func}{\mathsf{type}}~x, \href{../syntax/modules.html#syntax-func}{\mathsf{locals}}~\mathit{loc}^\ast, \href{../syntax/modules.html#syntax-func}{\mathsf{body}}~\mathit{in}^\ast~\href{../syntax/instructions.html#syntax-instr-control}{\mathsf{end}} \} \\ &&& \qquad\qquad\qquad
(\mathrel{\mbox{if}} I'' = I \href{../syntax/conventions.html#notation-compose}{\oplus} I' \href{../syntax/conventions.html#notation-compose}{\oplus} \{\href{../text/conventions.html#text-context}{\mathsf{locals}}~\mathrm{id}(\href{../text/modules.html#text-local}{\mathtt{local}})^\ast\} ~\href{../text/conventions.html#text-context-wf}{\mbox{well-formed}}) \\[1ex]
\def\mathdef3854#1{{}}\mathdef3854{local} & \href{../text/modules.html#text-local}{\mathtt{local}}_I &::=&
\def\mathdef3939#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3939{(}~\def\mathdef3940#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3940{local}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~t{:}\href{../text/types.html#text-valtype}{\mathtt{valtype}}_I~\def\mathdef3941#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3941{)}
\quad\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-local}{\mathsf{type}}~t \} \\
\end{array}\end{split}\]
The definition of the local identifier context \(I''\) uses the following auxiliary function to extract optional identifiers from locals:
\[\begin{split}\begin{array}{lcl@{\qquad\qquad}l}
\mathrm{id}(\def\mathdef3942#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3942{(}~\def\mathdef3943#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3943{local}~\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef3944#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3944{)}) &=& \href{../text/values.html#text-id}{\mathtt{id}}^? \\
\end{array}\end{split}\]
Note
The well-formedness condition on \(I''\) ensures that parameters and locals do not contain duplicate identifiers.
Abbreviations¶
Multiple anonymous locals may be combined into a single declaration:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{local} &
\def\mathdef3945#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3945{(}~~\def\mathdef3946#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3946{local}~~\href{../text/types.html#text-valtype}{\mathtt{valtype}}^\ast~~\def\mathdef3947#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3947{)} &\equiv&
(\def\mathdef3948#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3948{(}~~\def\mathdef3949#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3949{local}~~\href{../text/types.html#text-valtype}{\mathtt{valtype}}~~\def\mathdef3950#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3950{)})^\ast \\
\end{array}\end{split}\]
Functions can be defined as imports or exports inline:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef3951#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3951{(}~\def\mathdef3952#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3952{func}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef3953#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3953{(}~\def\mathdef3954#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3954{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~\def\mathdef3955#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3955{)}~~\href{../text/modules.html#text-typeuse}{\mathtt{typeuse}}~\def\mathdef3956#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3956{)} \quad\equiv \\ & \qquad
\def\mathdef3957#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3957{(}~\def\mathdef3958#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3958{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~~\def\mathdef3959#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3959{(}~\def\mathdef3960#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3960{func}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/modules.html#text-typeuse}{\mathtt{typeuse}}~\def\mathdef3961#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3961{)}~\def\mathdef3962#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3962{)} \\[1ex] &
\def\mathdef3963#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3963{(}~\def\mathdef3964#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3964{func}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef3965#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3965{(}~\def\mathdef3966#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3966{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~\def\mathdef3967#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3967{)}~~\dots~\def\mathdef3968#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3968{)} \quad\equiv \\ & \qquad
\def\mathdef3969#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3969{(}~\def\mathdef3970#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3970{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~~\def\mathdef3971#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3971{(}~\def\mathdef3972#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3972{func}~~\href{../text/values.html#text-id}{\mathtt{id}}'~\def\mathdef3973#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3973{)}~\def\mathdef3974#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3974{)}~~
\def\mathdef3975#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3975{(}~\def\mathdef3976#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3976{func}~~\href{../text/values.html#text-id}{\mathtt{id}}'~~\dots~\def\mathdef3977#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3977{)}
\\ & \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/values.html#text-id}{\mathtt{id}}^? \neq \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' = \href{../text/values.html#text-id}{\mathtt{id}}^? \vee \href{../text/values.html#text-id}{\mathtt{id}}^? = \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' ~\href{../text/values.html#text-id-fresh}{\mbox{fresh}}) \\
\end{array}\end{split}\]
Note
The latter abbreviation can be applied repeatedly, if “\(\dots\)” contains additional export clauses. Consequently, a function declaration can contain any number of exports, possibly followed by an import.
Tables¶
Table definitions can bind a symbolic table identifier.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{table} & \href{../text/modules.html#text-table}{\mathtt{table}}_I &::=&
\def\mathdef3978#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3978{(}~\def\mathdef3979#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3979{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\mathit{tt}{:}\href{../text/types.html#text-tabletype}{\mathtt{tabletype}}_I~~e{:}\href{../text/instructions.html#text-expr}{\mathtt{expr}}_I~\def\mathdef3980#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3980{)}
&\Rightarrow& \{ \href{../syntax/modules.html#syntax-table}{\mathsf{type}}~\mathit{tt}, \href{../syntax/modules.html#syntax-table}{\mathsf{init}}~e \} \\
\end{array}\end{split}\]
Abbreviations¶
A table’s initialization expression can be omitted, in which case it defaults to \(\href{../syntax/instructions.html#syntax-instr-ref}{\mathsf{ref.null}}\):
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef3981#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3981{(}~\def\mathdef3982#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3982{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/types.html#text-tabletype}{\mathtt{tabletype}}~\def\mathdef3983#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3983{)}
&\equiv&
\def\mathdef3984#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3984{(}~\def\mathdef3985#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3985{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/types.html#text-tabletype}{\mathtt{tabletype}}~~\def\mathdef3986#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3986{(}~\href{../syntax/instructions.html#syntax-instr-ref}{\mathsf{ref.null}}~\mathit{ht}~\def\mathdef3987#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3987{)}~\def\mathdef3988#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3988{)}
\\ &&& \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/types.html#text-tabletype}{\mathtt{tabletype}} = \href{../text/types.html#text-limits}{\mathtt{limits}}~\def\mathdef3989#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3989{(}~\def\mathdef3990#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3990{ref}~\def\mathdef3991#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3991{null}^?~\mathit{ht}~\def\mathdef3992#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3992{)}) \\
\end{array}\end{split}\]
An element segment can be given inline with a table definition, in which case its offset is \(0\) and the limits of the table type are inferred from the length of the given segment:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef3993#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3993{(}~\def\mathdef3994#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3994{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/types.html#text-reftype}{\mathtt{reftype}}~~\def\mathdef3995#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3995{(}~\def\mathdef3996#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3996{elem}~~\href{../syntax/instructions.html#syntax-expr}{\mathit{expr}}^n{:}\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\href{../text/modules.html#text-elemexpr}{\mathtt{elemexpr}})~\def\mathdef3997#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3997{)}~\def\mathdef3998#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3998{)} \quad\equiv \\ & \qquad
\def\mathdef3999#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef3999{(}~\def\mathdef4000#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4000{table}~~\href{../text/values.html#text-id}{\mathtt{id}}'~~n~~n~~\href{../text/types.html#text-reftype}{\mathtt{reftype}}~\def\mathdef4001#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4001{)} \\ & \qquad
\def\mathdef4002#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4002{(}~\def\mathdef4003#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4003{elem}~~\def\mathdef4004#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4004{(}~\def\mathdef4005#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4005{table}~~\href{../text/values.html#text-id}{\mathtt{id}}'~\def\mathdef4006#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4006{)}~~\def\mathdef4007#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4007{(}~\def\mathdef4008#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4008{i32.const}~~\def\mathdef4009#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4009{0}~\def\mathdef4010#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4010{)}~~\href{../text/types.html#text-reftype}{\mathtt{reftype}}~~\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\href{../text/modules.html#text-elemexpr}{\mathtt{elemexpr}})~\def\mathdef4011#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4011{)}
\\ & \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/values.html#text-id}{\mathtt{id}}^? \neq \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' = \href{../text/values.html#text-id}{\mathtt{id}}^? \vee \href{../text/values.html#text-id}{\mathtt{id}}^? = \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' ~\href{../text/values.html#text-id-fresh}{\mbox{fresh}}) \\
\end{array}\end{split}\]
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef4012#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4012{(}~\def\mathdef4013#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4013{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/types.html#text-reftype}{\mathtt{reftype}}~~\def\mathdef4014#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4014{(}~\def\mathdef4015#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4015{elem}~~x^n{:}\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}})~\def\mathdef4016#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4016{)}~\def\mathdef4017#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4017{)} \quad\equiv \\ & \qquad
\def\mathdef4018#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4018{(}~\def\mathdef4019#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4019{table}~~\href{../text/values.html#text-id}{\mathtt{id}}'~~n~~n~~\href{../text/types.html#text-reftype}{\mathtt{reftype}}~\def\mathdef4020#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4020{)} \\ & \qquad
\def\mathdef4021#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4021{(}~\def\mathdef4022#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4022{elem}~~\def\mathdef4023#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4023{(}~\def\mathdef4024#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4024{table}~~\href{../text/values.html#text-id}{\mathtt{id}}'~\def\mathdef4025#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4025{)}~~\def\mathdef4026#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4026{(}~\def\mathdef4027#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4027{i32.const}~~\def\mathdef4028#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4028{0}~\def\mathdef4029#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4029{)}~~\href{../text/types.html#text-reftype}{\mathtt{reftype}}~~\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\def\mathdef4030#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4030{(}~\def\mathdef4031#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4031{ref.func}~~\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}~\def\mathdef4032#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4032{)})~\def\mathdef4033#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4033{)}
\\ & \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/values.html#text-id}{\mathtt{id}}^? \neq \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' = \href{../text/values.html#text-id}{\mathtt{id}}^? \vee \href{../text/values.html#text-id}{\mathtt{id}}^? = \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' ~\href{../text/values.html#text-id-fresh}{\mbox{fresh}}) \\
\end{array}\end{split}\]
Tables can be defined as imports or exports inline:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef4034#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4034{(}~\def\mathdef4035#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4035{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4036#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4036{(}~\def\mathdef4037#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4037{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~\def\mathdef4038#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4038{)}~~\href{../text/types.html#text-tabletype}{\mathtt{tabletype}}~\def\mathdef4039#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4039{)} \quad\equiv \\ & \qquad
\def\mathdef4040#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4040{(}~\def\mathdef4041#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4041{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~~\def\mathdef4042#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4042{(}~\def\mathdef4043#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4043{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/types.html#text-tabletype}{\mathtt{tabletype}}~\def\mathdef4044#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4044{)}~\def\mathdef4045#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4045{)} \\[1ex] &
\def\mathdef4046#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4046{(}~\def\mathdef4047#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4047{table}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4048#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4048{(}~\def\mathdef4049#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4049{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~\def\mathdef4050#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4050{)}~~\dots~\def\mathdef4051#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4051{)} \quad\equiv \\ & \qquad
\def\mathdef4052#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4052{(}~\def\mathdef4053#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4053{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~~\def\mathdef4054#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4054{(}~\def\mathdef4055#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4055{table}~~\href{../text/values.html#text-id}{\mathtt{id}}'~\def\mathdef4056#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4056{)}~\def\mathdef4057#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4057{)}~~
\def\mathdef4058#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4058{(}~\def\mathdef4059#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4059{table}~~\href{../text/values.html#text-id}{\mathtt{id}}'~~\dots~\def\mathdef4060#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4060{)}
\\ & \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/values.html#text-id}{\mathtt{id}}^? \neq \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' = \href{../text/values.html#text-id}{\mathtt{id}}^? \vee \href{../text/values.html#text-id}{\mathtt{id}}^? = \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' ~\href{../text/values.html#text-id-fresh}{\mbox{fresh}}) \\
\end{array}\end{split}\]
Note
The latter abbreviation can be applied repeatedly, if “\(\dots\)” contains additional export clauses. Consequently, a table declaration can contain any number of exports, possibly followed by an import.
Memories¶
Memory definitions can bind a symbolic memory identifier.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{memory} & \href{../text/modules.html#text-mem}{\mathtt{mem}}_I &::=&
\def\mathdef4061#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4061{(}~\def\mathdef4062#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4062{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\mathit{mt}{:}\href{../text/types.html#text-memtype}{\mathtt{memtype}}_I~\def\mathdef4063#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4063{)}
&\Rightarrow& \{ \href{../syntax/modules.html#syntax-mem}{\mathsf{type}}~\mathit{mt} \} \\
\end{array}\end{split}\]
Abbreviations¶
A data segment can be given inline with a memory definition, in which case its offset is \(0\) and the limits of the memory type are inferred from the length of the data, rounded up to page size:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef4064#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4064{(}~\def\mathdef4065#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4065{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4066#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4066{(}~\def\mathdef4067#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4067{data}~~b^n{:}\href{../text/modules.html#text-datastring}{\mathtt{datastring}}~\def\mathdef4068#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4068{)}~~\def\mathdef4069#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4069{)} \quad\equiv \\ & \qquad
\def\mathdef4070#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4070{(}~\def\mathdef4071#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4071{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}'~~m~~m~\def\mathdef4072#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4072{)} \\ & \qquad
\def\mathdef4073#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4073{(}~\def\mathdef4074#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4074{data}~~\def\mathdef4075#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4075{(}~\def\mathdef4076#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4076{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}'~\def\mathdef4077#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4077{)}~~\def\mathdef4078#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4078{(}~\def\mathdef4079#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4079{i32.const}~~\def\mathdef4080#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4080{0}~\def\mathdef4081#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4081{)}~~\href{../text/modules.html#text-datastring}{\mathtt{datastring}}~\def\mathdef4082#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4082{)}
\\ & \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/values.html#text-id}{\mathtt{id}}^? \neq \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' = \href{../text/values.html#text-id}{\mathtt{id}}^? \vee \href{../text/values.html#text-id}{\mathtt{id}}^? = \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' ~\href{../text/values.html#text-id-fresh}{\mbox{fresh}}, m = \mathrm{ceil}(n / 64\,\mathrm{Ki})) \\
\end{array}\end{split}\]
Memories can be defined as imports or exports inline:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef4083#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4083{(}~\def\mathdef4084#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4084{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4085#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4085{(}~\def\mathdef4086#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4086{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~\def\mathdef4087#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4087{)}~~\href{../text/types.html#text-memtype}{\mathtt{memtype}}~\def\mathdef4088#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4088{)} \quad\equiv \\ & \qquad
\def\mathdef4089#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4089{(}~\def\mathdef4090#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4090{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~~\def\mathdef4091#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4091{(}~\def\mathdef4092#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4092{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/types.html#text-memtype}{\mathtt{memtype}}~\def\mathdef4093#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4093{)}~\def\mathdef4094#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4094{)}
\\[1ex] &
\def\mathdef4095#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4095{(}~\def\mathdef4096#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4096{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4097#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4097{(}~\def\mathdef4098#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4098{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~\def\mathdef4099#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4099{)}~~\dots~\def\mathdef4100#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4100{)} \quad\equiv \\ & \qquad
\def\mathdef4101#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4101{(}~\def\mathdef4102#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4102{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~~\def\mathdef4103#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4103{(}~\def\mathdef4104#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4104{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}'~\def\mathdef4105#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4105{)}~\def\mathdef4106#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4106{)}~~
\def\mathdef4107#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4107{(}~\def\mathdef4108#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4108{memory}~~\href{../text/values.html#text-id}{\mathtt{id}}'~~\dots~\def\mathdef4109#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4109{)}
\\ & \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/values.html#text-id}{\mathtt{id}}^? \neq \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' = \href{../text/values.html#text-id}{\mathtt{id}}^? \vee \href{../text/values.html#text-id}{\mathtt{id}}^? = \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' ~\href{../text/values.html#text-id-fresh}{\mbox{fresh}}) \\
\end{array}\end{split}\]
Note
The latter abbreviation can be applied repeatedly, if “\(\dots\)” contains additional export clauses. Consequently, a memory declaration can contain any number of exports, possibly followed by an import.
Globals¶
Global definitions can bind a symbolic global identifier.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{global} & \href{../text/modules.html#text-global}{\mathtt{global}}_I &::=&
\def\mathdef4110#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4110{(}~\def\mathdef4111#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4111{global}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\mathit{gt}{:}\href{../text/types.html#text-globaltype}{\mathtt{globaltype}}_I~~e{:}\href{../text/instructions.html#text-expr}{\mathtt{expr}}_I~\def\mathdef4112#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4112{)}
&\Rightarrow& \{ \href{../syntax/modules.html#syntax-global}{\mathsf{type}}~\mathit{gt}, \href{../syntax/modules.html#syntax-global}{\mathsf{init}}~e \} \\
\end{array}\end{split}\]
Abbreviations¶
Globals can be defined as imports or exports inline:
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{module field} &
\def\mathdef4113#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4113{(}~\def\mathdef4114#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4114{global}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4115#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4115{(}~\def\mathdef4116#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4116{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~\def\mathdef4117#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4117{)}~~\href{../text/types.html#text-globaltype}{\mathtt{globaltype}}~\def\mathdef4118#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4118{)} \quad\equiv \\ & \qquad
\def\mathdef4119#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4119{(}~\def\mathdef4120#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4120{import}~~\href{../text/values.html#text-name}{\mathtt{name}}_1~~\href{../text/values.html#text-name}{\mathtt{name}}_2~~\def\mathdef4121#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4121{(}~\def\mathdef4122#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4122{global}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\href{../text/types.html#text-globaltype}{\mathtt{globaltype}}~\def\mathdef4123#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4123{)}~\def\mathdef4124#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4124{)}
\\[1ex] &
\def\mathdef4125#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4125{(}~\def\mathdef4126#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4126{global}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4127#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4127{(}~\def\mathdef4128#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4128{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~\def\mathdef4129#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4129{)}~~\dots~\def\mathdef4130#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4130{)} \quad\equiv \\ & \qquad
\def\mathdef4131#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4131{(}~\def\mathdef4132#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4132{export}~~\href{../text/values.html#text-name}{\mathtt{name}}~~\def\mathdef4133#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4133{(}~\def\mathdef4134#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4134{global}~~\href{../text/values.html#text-id}{\mathtt{id}}'~\def\mathdef4135#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4135{)}~\def\mathdef4136#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4136{)}~~
\def\mathdef4137#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4137{(}~\def\mathdef4138#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4138{global}~~\href{../text/values.html#text-id}{\mathtt{id}}'~~\dots~\def\mathdef4139#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4139{)}
\\ & \qquad\qquad
(\mathrel{\mbox{if}} \href{../text/values.html#text-id}{\mathtt{id}}^? \neq \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' = \href{../text/values.html#text-id}{\mathtt{id}}^? \vee \href{../text/values.html#text-id}{\mathtt{id}}^? = \epsilon \wedge \href{../text/values.html#text-id}{\mathtt{id}}' ~\href{../text/values.html#text-id-fresh}{\mbox{fresh}}) \\
\end{array}\end{split}\]
Note
The latter abbreviation can be applied repeatedly, if “\(\dots\)” contains additional export clauses. Consequently, a global declaration can contain any number of exports, possibly followed by an import.
Exports¶
The syntax for exports mirrors their abstract syntax directly.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{export} & \href{../text/modules.html#text-export}{\mathtt{export}}_I &::=&
\def\mathdef4170#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4170{(}~\def\mathdef4171#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4171{export}~~\mathit{nm}{:}\href{../text/values.html#text-name}{\mathtt{name}}~~d{:}\href{../text/modules.html#text-exportdesc}{\mathtt{exportdesc}}_I~\def\mathdef4172#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4172{)}
&\Rightarrow& \{ \href{../syntax/modules.html#syntax-export}{\mathsf{name}}~\mathit{nm}, \href{../syntax/modules.html#syntax-export}{\mathsf{desc}}~d \} \\
\def\mathdef3854#1{{}}\mathdef3854{export description} & \href{../text/modules.html#text-exportdesc}{\mathtt{exportdesc}}_I &::=&
\def\mathdef4173#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4173{(}~\def\mathdef4174#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4174{func}~~x{:}\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}_I~\def\mathdef4175#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4175{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-exportdesc}{\mathsf{func}}~x \\ &&|&
\def\mathdef4176#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4176{(}~\def\mathdef4177#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4177{table}~~x{:}\href{../text/modules.html#text-tableidx}{\mathtt{tableidx}}_I~\def\mathdef4178#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4178{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-exportdesc}{\mathsf{table}}~x \\ &&|&
\def\mathdef4179#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4179{(}~\def\mathdef4180#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4180{memory}~~x{:}\href{../text/modules.html#text-memidx}{\mathtt{memidx}}_I~\def\mathdef4181#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4181{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-exportdesc}{\mathsf{mem}}~x \\ &&|&
\def\mathdef4182#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4182{(}~\def\mathdef4183#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4183{global}~~x{:}\href{../text/modules.html#text-globalidx}{\mathtt{globalidx}}_I~\def\mathdef4184#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4184{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-exportdesc}{\mathsf{global}}~x \\&&|&
\def\mathdef4185#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4185{(}~\def\mathdef4186#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4186{tag}~~x{:}\href{../text/modules.html#text-tagidx}{\mathtt{tagidx}}_I~\def\mathdef4187#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4187{)}
&\Rightarrow& \href{../syntax/modules.html#syntax-exportdesc}{\mathsf{tag}}~x \\
\end{array}\end{split}\]
Abbreviations¶
As an abbreviation, exports may also be specified inline with function, table, memory, global, or tag definitions; see the respective sections.
Start Function¶
A start function is defined in terms of its index.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{start function} & \href{../text/modules.html#text-start}{\mathtt{start}}_I &::=&
\def\mathdef4188#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4188{(}~\def\mathdef4189#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4189{start}~~x{:}\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}_I~\def\mathdef4190#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4190{)}
&\Rightarrow& \{ \href{../syntax/modules.html#syntax-start}{\mathsf{func}}~x \} \\
\end{array}\end{split}\]
Note
At most one start function may occur in a module, which is ensured by a suitable side condition on the \(\href{../text/modules.html#text-module}{\mathtt{module}}\) grammar.
Element Segments¶
Element segments allow for an optional table index to identify the table to initialize.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{element segment} & \href{../text/modules.html#text-elem}{\mathtt{elem}}_I &::=&
\def\mathdef4191#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4191{(}~\def\mathdef4192#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4192{elem}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~(et, y^\ast){:}\href{../text/modules.html#text-elemlist}{\mathtt{elemlist}}_I~\def\mathdef4193#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4193{)} \\ &&& \qquad
\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-elem}{\mathsf{type}}~et, \href{../syntax/modules.html#syntax-elem}{\mathsf{init}}~y^\ast, \href{../syntax/modules.html#syntax-elem}{\mathsf{mode}}~\href{../syntax/modules.html#syntax-elemmode}{\mathsf{passive}} \} \\ &&|&
\def\mathdef4194#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4194{(}~\def\mathdef4195#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4195{elem}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~x{:}\href{../text/modules.html#text-tableuse}{\mathtt{tableuse}}_I~~\def\mathdef4196#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4196{(}~\def\mathdef4197#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4197{offset}~~e{:}\href{../text/instructions.html#text-expr}{\mathtt{expr}}_I~\def\mathdef4198#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4198{)}~~(et, y^\ast){:}\href{../text/modules.html#text-elemlist}{\mathtt{elemlist}}_I~\def\mathdef4199#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4199{)} \\ &&& \qquad
\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-elem}{\mathsf{type}}~et, \href{../syntax/modules.html#syntax-elem}{\mathsf{init}}~y^\ast, \href{../syntax/modules.html#syntax-elem}{\mathsf{mode}}~\href{../syntax/modules.html#syntax-elemmode}{\mathsf{active}}~\{ \href{../syntax/modules.html#syntax-elem}{\mathsf{table}}~x, \href{../syntax/modules.html#syntax-elem}{\mathsf{offset}}~e \} \} \\ &&&
\def\mathdef4200#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4200{(}~\def\mathdef4201#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4201{elem}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4202#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4202{declare}~~(et, y^\ast){:}\href{../text/modules.html#text-elemlist}{\mathtt{elemlist}}_I~\def\mathdef4203#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4203{)} \\ &&& \qquad
\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-elem}{\mathsf{type}}~et, \href{../syntax/modules.html#syntax-elem}{\mathsf{init}}~y^\ast, \href{../syntax/modules.html#syntax-elem}{\mathsf{mode}}~\href{../syntax/modules.html#syntax-elemmode}{\mathsf{declarative}} \} \\
\def\mathdef3854#1{{}}\mathdef3854{element list} & \href{../text/modules.html#text-elemlist}{\mathtt{elemlist}}_I &::=&
t{:}\href{../text/types.html#text-reftype}{\mathtt{reftype}}_I~~y^\ast{:}\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\href{../text/modules.html#text-elemexpr}{\mathtt{elemexpr}}_I) \qquad\Rightarrow\quad ( \href{../syntax/modules.html#syntax-elem}{\mathsf{type}}~t, \href{../syntax/modules.html#syntax-elem}{\mathsf{init}}~y^\ast ) \\
\def\mathdef3854#1{{}}\mathdef3854{element expression} & \href{../text/modules.html#text-elemexpr}{\mathtt{elemexpr}}_I &::=&
\def\mathdef4204#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4204{(}~\def\mathdef4205#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4205{item}~~e{:}\href{../text/instructions.html#text-expr}{\mathtt{expr}}_I~\def\mathdef4206#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4206{)}
\quad\Rightarrow\quad e \\
\def\mathdef3854#1{{}}\mathdef3854{table use} & \href{../text/modules.html#text-tableuse}{\mathtt{tableuse}}_I &::=&
\def\mathdef4207#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4207{(}~\def\mathdef4208#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4208{table}~~x{:}\href{../text/modules.html#text-tableidx}{\mathtt{tableidx}}_I ~\def\mathdef4209#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4209{)}
\quad\Rightarrow\quad x \\
\end{array}\end{split}\]
Abbreviations¶
As an abbreviation, a single instruction may occur in place of the offset of an active element segment or as an element expression:
\[\begin{split}\begin{array}{llcll}
\def\mathdef3854#1{{}}\mathdef3854{element offset} &
\def\mathdef4210#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4210{(}~\href{../text/instructions.html#text-instr}{\mathtt{instr}}~\def\mathdef4211#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4211{)} &\equiv&
\def\mathdef4212#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4212{(}~\def\mathdef4213#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4213{offset}~~\href{../text/instructions.html#text-instr}{\mathtt{instr}}~\def\mathdef4214#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4214{)} \\
\def\mathdef3854#1{{}}\mathdef3854{element item} &
\def\mathdef4215#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4215{(}~\href{../text/instructions.html#text-instr}{\mathtt{instr}}~\def\mathdef4216#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4216{)} &\equiv&
\def\mathdef4217#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4217{(}~\def\mathdef4218#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4218{item}~~\href{../text/instructions.html#text-instr}{\mathtt{instr}}~\def\mathdef4219#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4219{)} \\
\end{array}\end{split}\]
Also, the element list may be written as just a sequence of function indices:
\[\begin{array}{llcll}
\def\mathdef3854#1{{}}\mathdef3854{element list} &
\def\mathdef4220#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4220{func}~~\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}_I) &\equiv&
\def\mathdef4221#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4221{(ref}~\def\mathdef4222#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4222{func)}~~\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\def\mathdef4223#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4223{(}~\def\mathdef4224#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4224{ref.func}~~\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}_I~\def\mathdef4225#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4225{)})
\end{array}\]
A table use can be omitted, defaulting to \(\mathtt{0}\). Furthermore, for backwards compatibility with earlier versions of WebAssembly, if the table use is omitted, the \(\def\mathdef4226#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4226{func}\) keyword can be omitted as well.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{table use} &
\epsilon &\equiv& \def\mathdef4227#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4227{(}~\def\mathdef4228#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4228{table}~~\def\mathdef4229#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4229{0}~\def\mathdef4230#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4230{)} \\
\def\mathdef3854#1{{}}\mathdef3854{element segment} &
\def\mathdef4231#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4231{(}~\def\mathdef4232#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4232{elem}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4233#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4233{(}~\def\mathdef4234#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4234{offset}~~\href{../text/instructions.html#text-expr}{\mathtt{expr}}_I~\def\mathdef4235#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4235{)}~~\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}_I)~\def\mathdef4236#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4236{)}
&\equiv&
\def\mathdef4237#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4237{(}~\def\mathdef4238#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4238{elem}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~\def\mathdef4239#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4239{(}~\def\mathdef4240#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4240{table}~~\def\mathdef4241#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4241{0}~\def\mathdef4242#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4242{)}~~\def\mathdef4243#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4243{(}~\def\mathdef4244#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4244{offset}~~\href{../text/instructions.html#text-expr}{\mathtt{expr}}_I~\def\mathdef4245#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4245{)}~~\def\mathdef4246#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4246{func}~~\href{../text/conventions.html#text-vec}{\mathtt{vec}}(\href{../text/modules.html#text-funcidx}{\mathtt{funcidx}}_I)~\def\mathdef4247#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4247{)}
\end{array}\end{split}\]
As another abbreviation, element segments may also be specified inline with table definitions; see the respective section.
Data Segments¶
Data segments allow for an optional memory index to identify the memory to initialize. The data is written as a string, which may be split up into a possibly empty sequence of individual string literals.
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{data segment} & \href{../text/modules.html#text-data}{\mathtt{data}}_I &::=&
\def\mathdef4248#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4248{(}~\def\mathdef4249#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4249{data}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~b^\ast{:}\href{../text/modules.html#text-datastring}{\mathtt{datastring}}~\def\mathdef4250#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4250{)} \\ &&& \qquad
\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-data}{\mathsf{init}}~b^\ast, \href{../syntax/modules.html#syntax-data}{\mathsf{mode}}~\href{../syntax/modules.html#syntax-datamode}{\mathsf{passive}} \} \\ &&|&
\def\mathdef4251#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4251{(}~\def\mathdef4252#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4252{data}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~x{:}\href{../text/modules.html#text-memuse}{\mathtt{memuse}}_I~~\def\mathdef4253#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4253{(}~\def\mathdef4254#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4254{offset}~~e{:}\href{../text/instructions.html#text-expr}{\mathtt{expr}}_I~\def\mathdef4255#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4255{)}~~b^\ast{:}\href{../text/modules.html#text-datastring}{\mathtt{datastring}}~\def\mathdef4256#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4256{)} \\ &&& \qquad
\Rightarrow\quad \{ \href{../syntax/modules.html#syntax-data}{\mathsf{init}}~b^\ast, \href{../syntax/modules.html#syntax-data}{\mathsf{mode}}~\href{../syntax/modules.html#syntax-datamode}{\mathsf{active}}~\{ \href{../syntax/modules.html#syntax-data}{\mathsf{memory}}~x', \href{../syntax/modules.html#syntax-data}{\mathsf{offset}}~e \} \} \\
\def\mathdef3854#1{{}}\mathdef3854{data string} & \href{../text/modules.html#text-datastring}{\mathtt{datastring}} &::=&
(b^\ast{:}\href{../text/values.html#text-string}{\mathtt{string}})^\ast \quad\Rightarrow\quad \href{../syntax/conventions.html#notation-concat}{\mathrm{concat}}((b^\ast)^\ast) \\
\def\mathdef3854#1{{}}\mathdef3854{memory use} & \href{../text/modules.html#text-memuse}{\mathtt{memuse}}_I &::=&
\def\mathdef4257#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4257{(}~\def\mathdef4258#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4258{memory}~~x{:}\href{../text/modules.html#text-memidx}{\mathtt{memidx}}_I ~\def\mathdef4259#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4259{)}
\quad\Rightarrow\quad x \\
\end{array}\end{split}\]
Note
In the current version of WebAssembly, the only valid memory index is 0 or a symbolic memory identifier resolving to the same value.
Abbreviations¶
As an abbreviation, a single instruction may occur in place of the offset of an active data segment:
\[\begin{array}{llcll}
\def\mathdef3854#1{{}}\mathdef3854{data offset} &
\def\mathdef4260#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4260{(}~\href{../text/instructions.html#text-instr}{\mathtt{instr}}~\def\mathdef4261#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4261{)} &\equiv&
\def\mathdef4262#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4262{(}~\def\mathdef4263#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4263{offset}~~\href{../text/instructions.html#text-instr}{\mathtt{instr}}~\def\mathdef4264#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4264{)}
\end{array}\]
Also, a memory use can be omitted, defaulting to \(\mathtt{0}\).
\[\begin{split}\begin{array}{llclll}
\def\mathdef3854#1{{}}\mathdef3854{memory use} &
\epsilon &\equiv& \def\mathdef4265#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4265{(}~\def\mathdef4266#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4266{memory}~~\def\mathdef4267#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4267{0}~\def\mathdef4268#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4268{)} \\
\end{array}\end{split}\]
As another abbreviation, data segments may also be specified inline with memory definitions; see the respective section.
Modules¶
A module consists of a sequence of fields that can occur in any order. All definitions and their respective bound identifiers scope over the entire module, including the text preceding them.
A module may optionally bind an identifier that names the module. The name serves a documentary role only.
Note
Tools may include the module name in the name section of the binary format.
\[\begin{split}\begin{array}{lll}
\def\mathdef3854#1{{}}\mathdef3854{module} & \href{../text/modules.html#text-module}{\mathtt{module}} &
\begin{array}[t]{@{}cllll}
::=&
\def\mathdef4269#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4269{(}~\def\mathdef4270#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4270{module}~~\href{../text/values.html#text-id}{\mathtt{id}}^?~~(m{:}\href{../text/modules.html#text-modulefield}{\mathtt{modulefield}}_I)^\ast~\def\mathdef4271#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4271{)}
\quad\Rightarrow\quad \href{../syntax/conventions.html#notation-compose}{\bigoplus} m^\ast \\
&\qquad (\mathrel{\mbox{if}} I = \href{../syntax/conventions.html#notation-compose}{\bigoplus} \mathrm{idc}(\href{../text/modules.html#text-modulefield}{\mathtt{modulefield}})^\ast ~\href{../text/conventions.html#text-context-wf}{\mbox{well-formed}}) \\
\end{array} \\[1ex]
\def\mathdef3854#1{{}}\mathdef3854{module field} & \href{../text/modules.html#text-modulefield}{\mathtt{modulefield}}_I &
\begin{array}[t]{@{}clll}
::=&
\mathit{ty}^\ast{:}\href{../text/types.html#text-rectype}{\mathtt{rectype}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{types}}~\mathit{ty}^\ast\} \\ |&
\mathit{im}{:}\href{../text/modules.html#text-import}{\mathtt{import}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{imports}}~\mathit{im}\} \\ |&
\mathit{fn}{:}\href{../text/modules.html#text-func}{\mathtt{func}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{funcs}}~\mathit{fn}\} \\ |&
\mathit{ta}{:}\href{../text/modules.html#text-table}{\mathtt{table}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{tables}}~\mathit{ta}\} \\ |&
\mathit{me}{:}\href{../text/modules.html#text-mem}{\mathtt{mem}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{mems}}~\mathit{me}\} \\ |&
\mathit{gl}{:}\href{../text/modules.html#text-global}{\mathtt{global}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{globals}}~\mathit{gl}\} \\ |&
\mathit{tg}{:}\href{../text/modules.html#text-tag}{\mathtt{tag}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{tags}}~\mathit{tg}\} \\ |&
\mathit{el}{:}\href{../text/modules.html#text-elem}{\mathtt{elem}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{elems}}~\mathit{el}\} \\ |&
\mathit{da}{:}\href{../text/modules.html#text-data}{\mathtt{data}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{datas}}~\mathit{da}\} \\ |&
\mathit{st}{:}\href{../text/modules.html#text-start}{\mathtt{start}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{start}}~\mathit{st}\} \\ |&
\mathit{ex}{:}\href{../text/modules.html#text-export}{\mathtt{export}}_I &\Rightarrow& \{\href{../syntax/modules.html#syntax-module}{\mathsf{exports}}~\mathit{ex}\} \\
\end{array}
\end{array}\end{split}\]
The following restrictions are imposed on the composition of modules: \(m_1 \href{../syntax/conventions.html#notation-compose}{\oplus} m_2\) is defined if and only if
\(m_1.\href{../syntax/modules.html#syntax-module}{\mathsf{start}} = \epsilon \vee m_2.\href{../syntax/modules.html#syntax-module}{\mathsf{start}} = \epsilon\)
\(m_1.\href{../syntax/modules.html#syntax-module}{\mathsf{funcs}} = m_1.\href{../syntax/modules.html#syntax-module}{\mathsf{tables}} = m_1.\href{../syntax/modules.html#syntax-module}{\mathsf{mems}} = m_1.\href{../syntax/modules.html#syntax-module}{\mathsf{globals}} = m_1.\href{../syntax/modules.html#syntax-module}{\mathsf{tags}} = \epsilon \vee m_2.\href{../syntax/modules.html#syntax-module}{\mathsf{imports}} = \epsilon\)
Note
The first condition ensures that there is at most one start function. The second condition enforces that all imports must occur before any regular definition of a function, table, memory, global, or tag, thereby maintaining the ordering of the respective index spaces.
The well-formedness condition on \(I\) in the grammar for \(\href{../text/modules.html#text-module}{\mathtt{module}}\) ensures that no namespace contains duplicate identifiers.
The definition of the initial identifier context \(I\) uses the following auxiliary definition which maps each relevant definition to a singular context with one (possibly empty) identifier:
\[\begin{split}\begin{array}{@{}lcl@{\qquad\qquad}l}
\mathrm{idc}(\def\mathdef4272#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4272{(}~\def\mathdef4273#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4273{rec}~~\href{../text/types.html#text-typedef}{\mathtt{typedef}}^\ast~\def\mathdef4274#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4274{)}) &=&
\href{../syntax/conventions.html#notation-compose}{\bigoplus} \mathrm{idc}(\href{../text/types.html#text-typedef}{\mathtt{typedef}})^\ast \\
\mathrm{idc}(\def\mathdef4275#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4275{(}~\def\mathdef4276#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4276{type}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\href{../text/types.html#text-subtype}{\mathtt{subtype}}~\def\mathdef4277#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4277{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{types}}~(v^?), \href{../text/conventions.html#text-context}{\mathsf{fields}}~\mathrm{idf}(\href{../text/types.html#text-subtype}{\mathtt{subtype}}), \href{../text/conventions.html#text-context}{\mathsf{typedefs}}~\mathit{st}\} \\
\mathrm{idc}(\def\mathdef4278#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4278{(}~\def\mathdef4279#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4279{func}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4280#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4280{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{funcs}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4281#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4281{(}~\def\mathdef4282#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4282{table}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4283#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4283{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{tables}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4284#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4284{(}~\def\mathdef4285#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4285{memory}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4286#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4286{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{mems}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4287#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4287{(}~\def\mathdef4288#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4288{global}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4289#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4289{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{globals}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4290#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4290{(}~\def\mathdef4291#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4291{tag}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4292#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4292{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{tags}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4293#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4293{(}~\def\mathdef4294#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4294{elem}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4295#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4295{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{elem}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4296#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4296{(}~\def\mathdef4297#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4297{data}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4298#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4298{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{data}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4299#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4299{(}~\def\mathdef4300#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4300{import}~\dots~\def\mathdef4301#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4301{(}~\def\mathdef4302#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4302{func}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4303#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4303{)}~\def\mathdef4304#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4304{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{funcs}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4305#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4305{(}~\def\mathdef4306#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4306{import}~\dots~\def\mathdef4307#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4307{(}~\def\mathdef4308#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4308{table}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4309#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4309{)}~\def\mathdef4310#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4310{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{tables}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4311#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4311{(}~\def\mathdef4312#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4312{import}~\dots~\def\mathdef4313#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4313{(}~\def\mathdef4314#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4314{memory}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4315#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4315{)}~\def\mathdef4316#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4316{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{mems}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4317#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4317{(}~\def\mathdef4318#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4318{import}~\dots~\def\mathdef4319#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4319{(}~\def\mathdef4320#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4320{global}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4321#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4321{)}~\def\mathdef4322#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4322{)}) &=&
\{\href{../text/conventions.html#text-context}{\mathsf{globals}}~(v^?)\} \\
\mathrm{idc}(\def\mathdef4323#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4323{(}~\dots~\def\mathdef4324#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4324{)}) &=&
\{\}
\\[2ex]
\mathrm{idf}(\def\mathdef4325#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4325{(}~\def\mathdef4326#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4326{sub}~\dots~\href{../text/types.html#text-comptype}{\mathtt{comptype}}~\def\mathdef4327#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4327{)}) &=&
\mathrm{idf}(\href{../text/types.html#text-comptype}{\mathtt{comptype}}) \\
\mathrm{idf}(\def\mathdef4328#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4328{(}~\def\mathdef4329#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4329{struct}~\mathit{Tfield}^\ast~\def\mathdef4330#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4330{)}) &=&
\href{../syntax/conventions.html#notation-compose}{\bigoplus} \mathrm{idf}(\href{../text/types.html#text-structtype}{\mathtt{field}})^\ast \\
\mathrm{idf}(\def\mathdef4331#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4331{(}~\def\mathdef4332#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4332{array}~\dots~\def\mathdef4333#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4333{)}) &=&
\epsilon \\
\mathrm{idf}(\def\mathdef4334#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4334{(}~\def\mathdef4335#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4335{func}~\dots~\def\mathdef4336#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4336{)}) &=&
\epsilon \\
\mathrm{idf}(\def\mathdef4337#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4337{(}~\def\mathdef4338#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4338{field}~v^?{:}\href{../text/values.html#text-id}{\mathtt{id}}^?~\dots~\def\mathdef4339#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4339{)}) &=&
v^? \\
\end{array}\end{split}\]
Abbreviations¶
In a source file, the toplevel \(\mathtt{(module}~\dots\mathtt{)}\) surrounding the module body may be omitted.
\[\begin{array}{llcll}
\def\mathdef3854#1{{}}\mathdef3854{module} &
\href{../text/modules.html#text-modulefield}{\mathtt{modulefield}}^\ast &\equiv&
\def\mathdef4340#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4340{(}~\def\mathdef4341#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4341{module}~~\href{../text/modules.html#text-modulefield}{\mathtt{modulefield}}^\ast~\def\mathdef4342#1{\mbox{‘}\mathtt{#1}\mbox{’}}\mathdef4342{)}
\end{array}\]