While loops 🔁

22 files changed, 260 insertions, 177 deletions

diff --git a/tests/ref/control/for-invalid.png b/tests/ref/control/for-invalid.png
deleted file mode 100644
index d758aa95..00000000
--- a/tests/ref/control/for-invalid.png
+++ /dev/null
diff --git a/tests/ref/control/for-value.png b/tests/ref/control/for-value.png
deleted file mode 100644
index fa323edc..00000000
--- a/tests/ref/control/for-value.png
+++ /dev/null
diff --git a/tests/ref/control/for.png b/tests/ref/control/for.png
index 2f13985a..cfbc8d08 100644
--- a/tests/ref/control/for.png
+++ b/tests/ref/control/for.png
diff --git a/tests/ref/control/if-invalid.png b/tests/ref/control/if-invalid.png
deleted file mode 100644
index 319fbdbd..00000000
--- a/tests/ref/control/if-invalid.png
+++ /dev/null
diff --git a/tests/ref/control/if.png b/tests/ref/control/if.png
index 75a20d00..7db3a8ae 100644
--- a/tests/ref/control/if.png
+++ b/tests/ref/control/if.png
diff --git a/tests/ref/control/invalid.png b/tests/ref/control/invalid.png
new file mode 100644
index 00000000..9a119088
--- /dev/null
+++ b/tests/ref/control/invalid.png
diff --git a/tests/ref/control/let-invalid.png b/tests/ref/control/let-invalid.png
deleted file mode 100644
index 19d4d545..00000000
--- a/tests/ref/control/let-invalid.png
+++ /dev/null
diff --git a/tests/ref/control/let-terminated.png b/tests/ref/control/let.png
index 24f20c69..24f20c69 100644
--- a/tests/ref/control/let-terminated.png
+++ b/tests/ref/control/let.png
diff --git a/tests/ref/control/while.png b/tests/ref/control/while.png
new file mode 100644
index 00000000..f0baf0af
--- /dev/null
+++ b/tests/ref/control/while.png
diff --git a/tests/ref/spacing.png b/tests/ref/spacing.png
index 5c3acf9b..fb102e66 100644
--- a/tests/ref/spacing.png
+++ b/tests/ref/spacing.png
diff --git a/tests/typ/control/for-invalid.typ b/tests/typ/control/for-invalid.typ
deleted file mode 100644
index c8bdebdd..00000000
--- a/tests/typ/control/for-invalid.typ
+++ /dev/null
@@ -1,32 +0,0 @@
-// Test invalid for loop syntax.
-
----
-// Error: 5-5 expected identifier
-#for
-
-// Error: 7-7 expected keyword `in`
-#for v
-
-// Error: 10-10 expected expression
-#for v in
-
-// Error: 15-15 expected body
-#for v in iter
-
----
-// Should output `v in iter`.
-// Error: 5 expected identifier
-#for
-v in iter {}
-
-// Should output `A thing`.
-// Error: 7-10 expected identifier, found string
-A#for "v" thing.
-
-// Should output `in iter`.
-// Error: 6-9 expected identifier, found string
-#for "v" in iter {}
-
-// Should output `+ b in iter`.
-// Error: 7 expected keyword `in`
-#for a + b in iter {}
diff --git a/tests/typ/control/for-value.typ b/tests/typ/control/for-value.typ
deleted file mode 100644
index 3ab80716..00000000
--- a/tests/typ/control/for-value.typ
+++ /dev/null
@@ -1,20 +0,0 @@
-// Test return value of for loops.
-
----
-// Template body yields template.
-// Should output `234`.
-#for v in (1, 2, 3, 4) [#if v >= 2 [{v}]]
-
----
-// Block body yields template.
-// Should output `[1st, 2nd, 3rd, 4th, 5th, 6th]`.
-{
-    "[" + for v in (1, 2, 3, 4, 5, 6) {
-        (if v > 1 [, ]
-            + [{v}]
-            + if v == 1 [st]
-            + if v == 2 [nd]
-            + if v == 3 [rd]
-            + if v >= 4 [th])
-     } + "]"
-}
diff --git a/tests/typ/control/for.typ b/tests/typ/control/for.typ
index 294345b5..36bce447 100644
--- a/tests/typ/control/for.typ
+++ b/tests/typ/control/for.typ
@@ -1,11 +1,10 @@
 // Test for loops.
-// Ref: false
 
 ---
-// Array.
-
-#for x in () {}
+// Empty array.
+#for x in () [Nope]
 
+// Array.
 #let sum = 0
 #for x in (1, 2, 3, 4, 5) {
     sum += x
@@ -13,14 +12,12 @@
 
 #test(sum, 15)
 
----
-// Dictionary.
-// Ref: true
-(\ #for k, v in (name: "Typst", age: 2) [
-    #h(0.5cm) {k}: {v}, \
-])
+// Dictionary is not traversed in insertion order.
+// Should output `age: 1, name: Typst,`.
+#for k, v in (name: "Typst", age: 2) [
+    {k}: {v}, \
+]
 
----
 // String.
 {
     let out = ""
@@ -36,6 +33,33 @@
 }
 
 ---
+// Block body.
+// Should output `[1st, 2nd, 3rd, 4th, 5th, 6th]`.
+{
+    "[" + for v in (1, 2, 3, 4, 5, 6) {
+        (if v > 1 [, ]
+            + [{v}]
+            + if v == 1 [st]
+            + if v == 2 [nd]
+            + if v == 3 [rd]
+            + if v >= 4 [th])
+     } + "]"
+}
+
+// Template body.
+// Should output `234`.
+#for v in (1, 2, 3, 4, 5, 6, 7) [#if v >= 2 and v <= 5 { repr(v) }]
+
+---
+// Value of for loops.
+// Ref: false
+#test(type(for v in () {}), "template")
+#test(type(for v in () []), "template")
+
+---
+// Error: 14-19 unknown variable
+#let error = error
+
 // Uniterable expression.
 // Error: 11-15 cannot loop over boolean
 #for v in true {}
@@ -44,9 +68,7 @@
 // Error: 11-18 cannot add integer and string
 #for v in 1 + "2" {}
 
-// Error: 14-17 cannot apply '-' to string
-#let error = -""
-#let result = for v in (1, 2, 3) {
+// A single error stops iteration.
+#test(error, for v in (1, 2, 3) {
     if v < 2 [Ok] else {error}
-}
-#test(result, error)
+})
diff --git a/tests/typ/control/if-invalid.typ b/tests/typ/control/if-invalid.typ
deleted file mode 100644
index 6d2deab1..00000000
--- a/tests/typ/control/if-invalid.typ
+++ /dev/null
@@ -1,28 +0,0 @@
-// Test invalid if syntax.
-
----
-// Error: 4 expected expression
-#if
-
-// Error: 4 expected expression
-{if}
-
-// Error: 6 expected body
-#if x
-
-// Error: 1-6 unexpected keyword `else`
-#else {}
-
----
-// Should output `x`.
-// Error: 4 expected expression
-#if
-x {}
-
-// Should output `something`.
-// Error: 6 expected body
-#if x something
-
-// Should output `A thing.`
-// Error: 20 expected body
-A#if false {} #else thing
diff --git a/tests/typ/control/if-value.typ b/tests/typ/control/if-value.typ
deleted file mode 100644
index d7124255..00000000
--- a/tests/typ/control/if-value.typ
+++ /dev/null
@@ -1,21 +0,0 @@
-// Test return value of if expressions.
-// Ref: false
-
----
-{
-    let x = 1
-    let y = 2
-    let z
-
-    // Returns if branch.
-    z = if x < y { "ok" }
-    test(z, "ok")
-
-    // Returns else branch.
-    z = if x > y { "bad" } else { "ok" }
-    test(z, "ok")
-
-    // Missing else evaluates to none.
-    z = if x > y { "bad" }
-    test(z, none)
-}
diff --git a/tests/typ/control/if.typ b/tests/typ/control/if.typ
index 4ed6b649..8d07e9b8 100644
--- a/tests/typ/control/if.typ
+++ b/tests/typ/control/if.typ
@@ -3,35 +3,61 @@
 ---
 // Test condition evaluation.
 #if 1 < 2 [
-    Ok.
+    One.
 ]
 
 #if true == false [
-    Bad, but we {dont-care}!
+    {Bad}, but we {dont-care}!
 ]
 
 ---
-// Brace in condition.
+// Braced condition.
 #if {true} [
-    Ok.
+    One.
+]
+
+// Template in condition.
+#if [] != none [
+    Two.
 ]
 
 // Multi-line condition with parens.
 #if (
     1 + 1
       == 1
-) {
-    nope
-} #else {
-    "Ok."
+) [
+    Nope.
+] #else {
+    "Three."
 }
 
 // Multiline.
 #if false [
     Bad.
 ] #else {
-    let pt = "."
-    "Ok" + pt
+    let point = "."
+    "Four" + point
+}
+
+---
+// Value of if expressions.
+// Ref: false
+{
+    let x = 1
+    let y = 2
+    let z
+
+    // Returns if branch.
+    z = if x < y { "ok" }
+    test(z, "ok")
+
+    // Returns else branch.
+    z = if x > y { "bad" } else { "ok" }
+    test(z, "ok")
+
+    // Missing else evaluates to none.
+    z = if x > y { "bad" }
+    test(z, none)
 }
 
 ---
diff --git a/tests/typ/control/invalid.typ b/tests/typ/control/invalid.typ
new file mode 100644
index 00000000..49158a68
--- /dev/null
+++ b/tests/typ/control/invalid.typ
@@ -0,0 +1,100 @@
+// Test invalid control syntax.
+
+---
+// Error: 5 expected identifier
+#let
+
+// Error: 5 expected identifier
+{let}
+
+// Error: 6-9 expected identifier, found string
+#let "v"
+
+// Should output `1`.
+// Error: 7 expected semicolon or line break
+#let v 1
+
+// Error: 9 expected expression
+#let v =
+
+// Should output `= 1`.
+// Error: 6-9 expected identifier, found string
+#let "v" = 1
+
+---
+// Error: 4 expected expression
+#if
+
+// Error: 4 expected expression
+{if}
+
+// Error: 6 expected body
+#if x
+
+// Error: 1-6 unexpected keyword `else`
+#else {}
+
+// Should output `x`.
+// Error: 4 expected expression
+#if
+x {}
+
+// Should output `something`.
+// Error: 6 expected body
+#if x something
+
+// Should output `A thing.`
+// Error: 20 expected body
+A#if false {} #else thing
+
+---
+// Error: 7 expected expression
+#while
+
+// Error: 7 expected expression
+{while}
+
+// Error: 9 expected body
+#while x
+
+// Should output `x`.
+// Error: 7 expected expression
+#while
+x {}
+
+// Should output `something`.
+// Error: 9 expected body
+#while x something
+
+---
+// Error: 5 expected identifier
+#for
+
+// Error: 5 expected identifier
+{for}
+
+// Error: 7 expected keyword `in`
+#for v
+
+// Error: 10 expected expression
+#for v in
+
+// Error: 15 expected body
+#for v in iter
+
+// Should output `v in iter`.
+// Error: 5 expected identifier
+#for
+v in iter {}
+
+// Should output `A thing`.
+// Error: 7-10 expected identifier, found string
+A#for "v" thing
+
+// Should output `in iter`.
+// Error: 6-9 expected identifier, found string
+#for "v" in iter {}
+
+// Should output `+ b in iter`.
+// Error: 7 expected keyword `in`
+#for a + b in iter {}
diff --git a/tests/typ/control/let-invalid.typ b/tests/typ/control/let-invalid.typ
deleted file mode 100644
index f29353ed..00000000
--- a/tests/typ/control/let-invalid.typ
+++ /dev/null
@@ -1,20 +0,0 @@
-// Test invalid let binding syntax.
-
----
-// Error: 5 expected identifier
-#let
-
-// Error: 6-9 expected identifier, found string
-#let "v"
-
-// Should output `1`.
-// Error: 7 expected semicolon or line break
-#let v 1
-
-// Error: 9 expected expression
-#let v =
-
----
-// Should output `= 1`.
-// Error: 6-9 expected identifier, found string
-#let "v" = 1
diff --git a/tests/typ/control/let-terminated.typ b/tests/typ/control/let-terminated.typ
deleted file mode 100644
index 623265e0..00000000
--- a/tests/typ/control/let-terminated.typ
+++ /dev/null
@@ -1,28 +0,0 @@
-// Test termination of let statements.
-
----
-// Terminated by line break.
-#let v1 = 1
-One
-
-// Terminated by semicolon.
-#let v2 = 2; Two
-
-// Terminated by semicolon and line break.
-#let v3 = 3;
-Three
-
-// Terminated because expression ends.
-// Error: 12 expected semicolon or line break
-#let v4 = 4 Four
-
-// Terminated by semicolon even though we are in a paren group.
-// Error: 2:19 expected expression
-// Error: 1:19 expected closing paren
-#let v5 = (1, 2 + ; Five
-
-#test(v1, 1)
-#test(v2, 2)
-#test(v3, 3)
-#test(v4, 4)
-#test(v5, (1, 2))
diff --git a/tests/typ/control/let.typ b/tests/typ/control/let.typ
index e609d3a9..8df29b11 100644
--- a/tests/typ/control/let.typ
+++ b/tests/typ/control/let.typ
@@ -1,7 +1,8 @@
 // Test let bindings.
-// Ref: false
 
 ---
+// Ref: false
+
 // Automatically initialized with none.
 #let x
 #test(x, none)
@@ -9,3 +10,32 @@
 // Manually initialized with one.
 #let x = 1
 #test(x, 1)
+
+---
+// Termination.
+
+// Terminated by line break.
+#let v1 = 1
+One
+
+// Terminated by semicolon.
+#let v2 = 2; Two
+
+// Terminated by semicolon and line break.
+#let v3 = 3;
+Three
+
+// Terminated because expression ends.
+// Error: 12 expected semicolon or line break
+#let v4 = 4 Four
+
+// Terminated by semicolon even though we are in a paren group.
+// Error: 2:19 expected expression
+// Error: 1:19 expected closing paren
+#let v5 = (1, 2 + ; Five
+
+#test(v1, 1)
+#test(v2, 2)
+#test(v3, 3)
+#test(v4, 4)
+#test(v5, (1, 2))
diff --git a/tests/typ/control/while.typ b/tests/typ/control/while.typ
new file mode 100644
index 00000000..7ad70372
--- /dev/null
+++ b/tests/typ/control/while.typ
@@ -0,0 +1,46 @@
+// Test while expressions.
+
+---
+// Should output `2 4 6 8 10`.
+#let i = 0
+#while i < 10 [
+    { i += 2 }
+    #i
+]
+
+// Should output `Hi`.
+#let iter = true
+#while iter {
+    iter = false
+    "Hi."
+}
+
+#while false {
+    dont-care
+}
+
+---
+// Value of while loops.
+// Ref: false
+#test(type(while false {}), "template")
+#test(type(while false []), "template")
+
+---
+// Error: 14-19 unknown variable
+#let error = error
+
+// Condition must be boolean.
+// Error: 8-14 expected boolean, found template
+#while [nope] [nope]
+
+// Make sure that we don't complain twice.
+// Error: 8-15 unknown variable
+#while nothing {}
+
+// A single error stops iteration.
+#let i = 0
+#test(error, while i < 10 {
+    i += 1
+    if i < 5 [nope] else { error }
+})
+#test(i, 5)
diff --git a/tests/typ/spacing.typ b/tests/typ/spacing.typ
index d44cd84c..77dac53c 100644
--- a/tests/typ/spacing.typ
+++ b/tests/typ/spacing.typ
@@ -20,8 +20,16 @@ A#if false [] #else [B]C \
 A#if true [B] #else [] C \
 
 ---
+// Spacing around while loop.
+
+#let c = true; A#while c [{c = false}B]C \
+#let c = true; A#while c [{c = false}B] C \
+#let c = true; A #while c { c = false; "B" }C \
+#let c = true; A #while c { c = false; "B" } C \
+
+---
 // Spacing around for loop.
 
 A#for _ in (none,) [B]C  \
 A#for _ in (none,) [B] C \
-A #for _ in (none,) [B]C \
+A #for _ in (none,) {"B"}C \