nandi.uk
Fork of daniellemaywood.uk/gleam — Wasm codegen work
reuse assignment var in pattern matching code gen
author
Giacomo Cavalieri
committer
Louis Pilfold
date
(Apr 30, 2025, 3:47 PM +0100)
commit
e3460064
e346006413b35fd538dc907260f0c1f5712bdb5f
parent
41cd929b
41cd929b063ab03011cac43298591c2de0a6952c
+78
-78
+1
-1
compiler-core/src/javascript/decision.rs
+1
-1
compiler-core/src/javascript/decision.rs
···
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// name so we can use this variable to reference it and never
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// do any duplicate work recomputing its value every time
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// this pattern variable is used.
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-
let name = self.variables.next_local_var(&"pattern".into());
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let name = self.variables.next_local_var(&ASSIGNMENT_VAR.into());
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let value = self.variables.get_value(var);
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self.variables.bind(name.clone(), var);
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docvec![let_(name, value.to_doc()), line()]
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__case_branches_guards_are_wrapped_in_parentheses.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__case_branches_guards_are_wrapped_in_parentheses.snap
+3
-3
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__deeply_nested_string_prefix_assignment.snap
+3
-3
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__deeply_nested_string_prefix_assignment.snap
···
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export function main() {
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let tmp = new Wibble(new Wobble(new Wabble([42, "wibble"])));
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let pattern = tmp[0].wabble.tuple[1];
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if (pattern.startsWith("w")) {
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let $ = tmp[0].wabble.tuple[1];
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if ($.startsWith("w")) {
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let wibble = "w";
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-
let rest = pattern.slice(1);
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let rest = $.slice(1);
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return wibble + rest;
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} else {
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throw makeError(
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-5
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__guard_variable_only_brought_into_scope_when_needed.snap
+5
-5
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__guard_variable_only_brought_into_scope_when_needed.snap
···
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if (x instanceof $Empty) {
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return 2;
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} else {
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let pattern = x.tail;
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if (pattern instanceof $Empty) {
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let $ = x.tail;
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if ($ instanceof $Empty) {
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return 2;
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} else {
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-
let pattern$1 = pattern.tail;
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-
if (pattern$1 instanceof $Empty) {
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let $1 = $.tail;
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if ($1 instanceof $Empty) {
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let a = x.head;
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if (a === 1) {
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let b = pattern.head;
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let b = $.head;
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return a + b;
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} else {
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return 2;
+3
-3
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__nested_string_prefix_assignment.snap
+3
-3
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__nested_string_prefix_assignment.snap
···
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export function main() {
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let tmp = new Wibble("wibble");
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let pattern = tmp.wobble;
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-
if (pattern.startsWith("w")) {
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let $ = tmp.wobble;
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if ($.startsWith("w")) {
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let wibble = "w";
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let rest = pattern.slice(1);
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let rest = $.slice(1);
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return wibble + rest;
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} else {
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throw makeError(
+14
-14
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__nested_string_prefix_match.snap
+14
-14
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__nested_string_prefix_match.snap
···
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function main() {
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let $ = new Ok(toList(["a", "b c", "d"]));
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let pattern = $[0];
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if (pattern instanceof $Empty) {
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let $1 = $[0];
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if ($1 instanceof $Empty) {
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return 1;
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} else {
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let pattern$1 = pattern.tail;
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if (pattern$1 instanceof $Empty) {
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let $2 = $1.tail;
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if ($2 instanceof $Empty) {
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return 1;
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} else {
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let pattern$2 = pattern$1.tail;
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-
if (pattern$2 instanceof $Empty) {
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let $3 = $2.tail;
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if ($3 instanceof $Empty) {
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return 1;
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} else {
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-
let pattern$3 = pattern$2.tail;
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if (pattern$3 instanceof $Empty) {
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let pattern$4 = pattern$2.head;
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if (pattern$4 === "d") {
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let pattern$5 = pattern$1.head;
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if (pattern$5.startsWith("b ")) {
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let pattern$6 = pattern.head;
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if (pattern$6 === "a") {
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let $4 = $3.tail;
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if ($4 instanceof $Empty) {
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let $5 = $3.head;
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if ($5 === "d") {
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let $6 = $2.head;
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if ($6.startsWith("b ")) {
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let $7 = $1.head;
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if ($7 === "a") {
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return 1;
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} else {
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return 1;
+10
-10
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__nested_string_prefix_match_that_would_crash_on_js.snap
+10
-10
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__nested_string_prefix_match_that_would_crash_on_js.snap
···
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function main() {
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let $ = new Ok(toList(["b c", "d"]));
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let pattern = $[0];
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if (pattern instanceof $Empty) {
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let $1 = $[0];
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if ($1 instanceof $Empty) {
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return 1;
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} else {
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let pattern$1 = pattern.tail;
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if (pattern$1 instanceof $Empty) {
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let $2 = $1.tail;
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if ($2 instanceof $Empty) {
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return 1;
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} else {
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let pattern$2 = pattern$1.tail;
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if (pattern$2 instanceof $Empty) {
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let pattern$3 = pattern$1.head;
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if (pattern$3 === "d") {
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let pattern$4 = pattern.head;
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-
if (pattern$4.startsWith("b ")) {
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let $3 = $2.tail;
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if ($3 instanceof $Empty) {
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let $4 = $2.head;
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if ($4 === "d") {
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let $5 = $1.head;
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if ($5.startsWith("b ")) {
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return 1;
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} else {
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return 1;
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__tuple_and_guard.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__tuple_and_guard.snap
+5
-5
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__alternative_patterns_assignment.snap
+5
-5
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__alternative_patterns_assignment.snap
···
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if (xs instanceof $Empty) {
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return 1;
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} else {
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let pattern = xs.tail;
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-
if (pattern instanceof $Empty) {
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let $ = xs.tail;
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if ($ instanceof $Empty) {
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let x = xs.head;
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return x;
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} else {
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let pattern$1 = pattern.tail;
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if (pattern$1 instanceof $Empty) {
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let x = pattern.head;
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let $1 = $.tail;
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if ($1 instanceof $Empty) {
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let x = $.head;
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return x;
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} else {
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return 1;
+5
-5
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__alternative_patterns_guard.snap
+5
-5
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__alternative_patterns_guard.snap
···
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if (xs instanceof $Empty) {
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return 0;
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} else {
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let pattern = xs.tail;
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if (pattern instanceof $Empty) {
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let $ = xs.tail;
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if ($ instanceof $Empty) {
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let x = xs.head;
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if (x === 1) {
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return x;
···
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return 0;
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}
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} else {
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let pattern$1 = pattern.tail;
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if (pattern$1 instanceof $Empty) {
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let x = pattern.head;
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let $1 = $.tail;
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if ($1 instanceof $Empty) {
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let x = $.head;
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if (x === 1) {
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return x;
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} else {
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-10
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__alternative_patterns_list.snap
+10
-10
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__alternative_patterns_list.snap
···
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if (xs instanceof $Empty) {
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return 1;
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} else {
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let pattern = xs.tail;
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if (pattern instanceof $Empty) {
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let pattern$1 = xs.head;
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if (pattern$1 === 1) {
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let $ = xs.tail;
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if ($ instanceof $Empty) {
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let $1 = xs.head;
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if ($1 === 1) {
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return 0;
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} else {
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return 1;
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}
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} else {
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let pattern$1 = pattern.tail;
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if (pattern$1 instanceof $Empty) {
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let pattern$2 = pattern.head;
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if (pattern$2 === 2) {
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-
let pattern$3 = xs.head;
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-
if (pattern$3 === 1) {
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+
let $1 = $.tail;
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+
if ($1 instanceof $Empty) {
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let $2 = $.head;
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+
if ($2 === 2) {
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+
let $3 = xs.head;
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if ($3 === 1) {
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return 0;
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} else {
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return 1;
+4
-4
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__custom_types__imported_pattern.snap
+4
-4
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__custom_types__imported_pattern.snap
···
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import { Two } from "../other.mjs";
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export function main(x) {
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-
let pattern = x.a;
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-
if (pattern === 1) {
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+
let $ = x.a;
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+
if ($ === 1) {
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return 1;
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} else {
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-
let pattern$1 = x.b;
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-
if (pattern$1 === 2) {
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+
let $1 = x.b;
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+
if ($1 === 2) {
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let c = x.c;
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return c;
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} else {
+4
-4
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__lists__case.snap
+4
-4
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__lists__case.snap
···
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if (xs instanceof $Empty) {
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return 0;
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} else {
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-
let pattern = xs.tail;
25
-
if (pattern instanceof $Empty) {
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+
let $ = xs.tail;
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+
if ($ instanceof $Empty) {
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return 1;
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} else {
28
-
let pattern$1 = pattern.tail;
29
-
if (pattern$1 instanceof $Empty) {
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+
let $1 = $.tail;
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+
if ($1 instanceof $Empty) {
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return 2;
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} else {
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return 9999;
+8
-8
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__tuples__case.snap
+8
-8
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__tuples__case.snap
···
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----- COMPILED JAVASCRIPT
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function go(a) {
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-
let pattern = a[0];
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if (pattern === 2) {
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+
let $ = a[0];
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+
if ($ === 2) {
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let a$1 = a[1];
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return a$1;
22
-
} else if (pattern === 1) {
23
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let pattern$1 = a[1];
24
-
if (pattern$1 === 1) {
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+
} else if ($ === 1) {
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+
let $1 = a[1];
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+
if ($1 === 1) {
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return 1;
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} else {
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-
let a$1 = pattern;
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-
let b = pattern$1;
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+
let a$1 = $;
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+
let b = $1;
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return a$1 + b;
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}
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} else {
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-
let a$1 = pattern;
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+
let a$1 = $;
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let b = a[1];
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return a$1 + b;
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}
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__tuples__nested_pattern.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__tuples__nested_pattern.snap