nandi.uk
Fork of daniellemaywood.uk/gleam — Wasm codegen work
Fix scoping of blocks
author
GearsDatapacks
committer
Louis Pilfold
date
(Mar 16, 2025, 2:01 PM UTC)
commit
be6815a1
be6815a1725218c9b410249111a8598307a17fdd
parent
c9f8c62e
c9f8c62e86e4307303d6709509653013ab92c4db
+92
-26
+39
-23
compiler-core/src/javascript/expression.rs
+39
-23
compiler-core/src/javascript/expression.rs
···
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result
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}
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fn wrap_block<CompileFn>(&mut self, compile: CompileFn) -> Output<'a>
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where
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CompileFn: Fn(&mut Self) -> Output<'a>,
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{
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let block_variable = self.next_local_var(&BLOCK_VARIABLE.into());
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// Save initial state
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let scope_position = std::mem::replace(
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&mut self.scope_position,
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Position::Assign(block_variable.clone()),
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);
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let function_position = std::mem::replace(&mut self.function_position, Position::NotTail);
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// Generate the expression
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let statement_doc = compile(self)?;
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self.statement_level
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.push(docvec!["let ", block_variable.clone(), ";"]);
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self.statement_level.push(statement_doc);
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// Reset
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self.scope_position = scope_position;
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self.function_position = function_position;
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Ok(self.wrap_return(block_variable.to_doc()))
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}
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/// Use the `_block` variable if the expression is JS statement.
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pub fn wrap_expression(&mut self, expression: &'a TypedExpr) -> Output<'a> {
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match expression {
···
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| TypedExpr::Todo { .. }
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| TypedExpr::Case { .. }
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| TypedExpr::Pipeline { .. }
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| TypedExpr::RecordUpdate { .. } => {
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let block_variable = self.next_local_var(&BLOCK_VARIABLE.into());
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let statement_doc = self.not_in_tail_position(|this| {
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this.scope_position = Position::Assign(block_variable.clone());
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this.expression(expression)
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})?;
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self.statement_level
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.push(docvec!["let ", block_variable.clone(), ";"]);
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self.statement_level.push(statement_doc);
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Ok(self.wrap_return(block_variable.to_doc()))
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}
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| TypedExpr::RecordUpdate { .. } => self.wrap_block(|this| this.expression(expression)),
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_ => self.expression(expression),
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}
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}
···
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}
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} else {
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match &self.scope_position {
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Position::Tail | Position::Assign(_) => return self.block_document(statements),
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Position::NotTail => {}
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}
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Position::Tail | Position::Assign(_) => self.block_document(statements),
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Position::NotTail => self.wrap_block(|this| {
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// Save previous scope
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let current_scope_vars = this.current_scope_vars.clone();
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let block_variable = self.next_local_var(&BLOCK_VARIABLE.into());
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let statements = self.not_in_tail_position(|this| {
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this.scope_position = Position::Assign(block_variable.clone());
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this.block_document(statements)
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})?;
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self.statement_level
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.push(docvec!["let ", block_variable.clone(), ";"]);
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self.statement_level.push(statements);
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Ok(self.wrap_return(block_variable.to_doc()))
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let document = this.block_document(statements)?;
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// Restore previous state
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this.current_scope_vars = current_scope_vars;
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Ok(document)
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}),
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}
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}
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}
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+18
compiler-core/src/javascript/tests/blocks.rs
+18
compiler-core/src/javascript/tests/blocks.rs
+1
-1
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__assignments__variable_renaming.snap
+1
-1
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__assignments__variable_renaming.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__blocks__nested_multiexpr_blocks_with_pipe.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__blocks__nested_multiexpr_blocks_with_pipe.snap
+32
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__blocks__shadowed_variable_in_nested_scope.snap
+32
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__blocks__shadowed_variable_in_nested_scope.snap
···
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---
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source: compiler-core/src/javascript/tests/blocks.rs
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expression: "\npub fn main() {\n {\n let x = 1\n let _ = {\n let x = 2\n x\n }\n x\n }\n}\n"
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---
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----- SOURCE CODE
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pub fn main() {
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{
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let x = 1
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let _ = {
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let x = 2
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x
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}
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x
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}
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}
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----- COMPILED JAVASCRIPT
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export function main() {
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{
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let x = 1;
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let _block;
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{
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let x$1 = 2;
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_block = x$1;
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}
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let $ = _block;
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return x;
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}
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}