[add] quan function

README.md

@@ -363,9 +363,25 @@ Zero not only aligns numbers at the decimal point but also at the uncertainty an
 
 ## Units and Quantities
 
-Numbers are frequently displayed together with a (physical) unit forming a so-called _quantity_. Zero has built-in support for formatting quantities through the `zi` module. 
+Numbers are frequently displayed together with a (physical) unit forming a so-called _quantity_. Zero has built-in support for formatting quantities through two different philosophies.
+<!-- the `zi` module.  -->
 
-Zero takes a different approach to units than other packages: In order to avoid repetition ([DRY principle](https://en.wikipedia.org/wiki/Don%27t_repeat_yourself)) and to avoid accidental errors, every unit is
+<!-- Zero takes a different approach to units than other packages: -->
+### 1. The `quan` function
+The function `quan` 
+Similar to `num`, the function `quan` takes one argument, specifying a value and a unit − or just one of them. A few examples:
+- `quan[1.2 m/s]` - the space is optional
+- `quan[-2.0+-.4e3 m/s]` - the value works just like `num`
+- `quan[GHz]` - units can also go without a value
+- `quan[600us]` - "u" is changed to "µ"
+
+The precise syntax for specifying units is explained in the next section.
+Units of the SI system and units that may be used in compliance with the SI system are automatically recognized and annotated with alt descriptions, see also [accessibility](#accessibility) below.
+
+
+### 2. Predefined units
+
+In order to avoid repetition ([DRY principle](https://en.wikipedia.org/wiki/Don%27t_repeat_yourself)) and to avoid accidental errors, every unit can be
 - first _declared_ (or already predefined)
 - and then used as a function to produce a quantity. 
 
@@ -389,7 +405,7 @@ Take a look at the example below:
 </p>
 
 
-### Declaring a New Unit
+#### Declaring a New Unit
 
 All common single units as well as a few frequent combinations are already predefined in the `zi` module (e.g., `zi.m`, `zi.V`, `zi.m-s`). 
 

src/parsing.typ

@@ -14,9 +14,9 @@
   if (
     body.has("children")
       and body.children.len() != 0
-      and body.children.all(child => child.has("text"))
+      and body.children.all(child => child.has("text") or child == [ ])
   ) {
-    body.children.map(child => child.text).join()
+    body.children.map(child => if child == [ ] { " " } else { child.text }).join()
   }
 }
 

src/quan.typ

@@ -0,0 +1,40 @@
+#import "num.typ": num
+#import "parsing.typ": content-to-string
+#import "units.typ": parse-unit, qty, unit
+
+#let quan(input) = {
+  if type(input) == content {
+    input = content-to-string(input)
+    assert(input != none, message: "")
+  }
+
+  let regex-beginning-of-unit = regex("[ a-zA-Zµ/]")
+
+
+  // We need to protect against detecting the e/E exponent notation as a unit
+  let e-position = lower(input).position("e")
+  let pos = if (
+    e-position != none
+      and input.at(e-position + 1, default: ".") in "+-1234567890.,"
+  ) {
+    let pos = input.slice(e-position + 1).position(regex-beginning-of-unit)
+    if pos != none {
+      pos += e-position + 1
+    }
+    pos
+  } else {
+    input.position(regex-beginning-of-unit)
+  }
+
+  if pos == none {
+    num(input)
+  } else if pos == 0 {
+    unit(parse-unit(input))
+  } else {
+    qty(
+      input.slice(0, pos),
+      parse-unit(input.slice(pos)),
+    )
+  }
+}
+

src/units.typ

@@ -57,6 +57,9 @@
       }
 
       let (symbol, exponent) = get-symbol-and-exponent(unit, per)
+      if symbol.starts-with("u") {
+        symbol = "µ" + symbol.slice(1)
+      }
       if exponent.starts-with("-") {
         per = not per
         exponent = exponent.slice(1)

src/zero.typ

@@ -4,3 +4,4 @@
 #import "align-column.typ": align-column
 #import "zi.typ"
 #import "units.typ": set-unit
+#import "quan.typ": quan

tests/internal/parsing/test.typ

@@ -36,9 +36,9 @@
 // unparsable inputs
 #assert.eq(to-normalized-numeral[], none)
 #assert.eq(to-normalized-numeral[$a + b$], none)
-#assert.eq(to-normalized-numeral[2 ], none)
-#assert.eq(to-normalized-numeral[ 2], none)
-#assert.eq(to-normalized-numeral[ 2343.23 ], none)
+#assert.eq(to-normalized-numeral-table[2 ], none)
+#assert.eq(to-normalized-numeral-table[ 2], none)
+#assert.eq(to-normalized-numeral-table[ 2343.23 ], none)
 #assert.eq(str(sym.plus), "+")
 
 

tests/quan/.gitignore

@@ -0,0 +1,5 @@
+# generated by tytanic, do not edit
+
+/diff/
+/out/
+/ref/

tests/quan/ref.typ

@@ -0,0 +1,33 @@
+#set page(width: auto, height: auto, margin: .5em)
+#import "/src/zero.typ": *
+
+
+#zi.m-s[12.3] \
+#zi.electronvolt[12.3] \
+#(zi.declare("/s"))[12.3] \
+#zi.m-s[12.3] \
+#zi.electronvolt[12.3] \
+#(zi.declare("/s"))[12.3] \
+
+#pagebreak()
+
+#zi.electronvolt[12.3e-2] \
+#(zi.declare("EHz"))[12.3e-2] \
+#(zi.declare("EHz"))[12.3e-2] \
+#zi.electronvolt[12.3e2] \
+#(zi.declare("EHz"))[12.3e2] \
+#(zi.declare("EHz"))[12.3e2] \
+#zi.electronvolt[12.3e2] \
+#(zi.declare("EHz"))[12.3e2] \
+#(zi.declare("EHz"))[12.3e2] \
+
+#pagebreak()
+
+#(zi.declare("m muN^4/s^2"))[-12+-4e3]
+
+#pagebreak()
+
+#num[12+-23] \
+#zi.astronomicalunit() \
+#zi.m-s() \
+#zi.us() \

tests/quan/test.typ

@@ -0,0 +1,35 @@
+#set page(width: auto, height: auto, margin: .5em)
+#import "/src/zero.typ": *
+
+
+
+
+#quan[12.3m/s] \
+#quan[12.3eV] \
+#quan[12.3/s] \
+#quan[12.3 m/s] \
+#quan[12.3 eV] \
+#quan[12.3 /s] \
+
+#pagebreak()
+
+#quan[12.3e-2eV] \
+#quan[12.3E-2EHz] \
+#quan[12.3E-2 EHz] \
+#quan[12.3e+2eV] \
+#quan[12.3E+2EHz] \
+#quan[12.3E+2 EHz] \
+#quan[12.3e2eV] \
+#quan[12.3E2EHz] \
+#quan[12.3E2 EHz] \
+
+#pagebreak()
+
+#quan[-12.3+-4e3 m/s^2 muN^4]
+
+#pagebreak()
+
+#quan[12+-23] \
+#quan[au] \
+#quan[m/s] \
+#quan[us] \