refactor: split complex functions into helpers (S3776)

Lower the cognitive complexity of paragraph, axis_scale, modify_ref_list,
fill and reconstruct by moving their per-run, per-axis-limit, per-entry,
per-request and per-block steps into helpers. The expressions and their
evaluation order are unchanged.

crates/engine/src/cmd/shape.rs

@@ -5,7 +5,7 @@ use std::collections::HashMap;
 
 use deckcraft_color::{ColorTransform, Rgba, SchemeSlot};
 use deckcraft_model::style::{Dash, Glow, Gradient, GradientShape, GradientStop, LineEnd, PatternFill, PictureFill, PictureMode, Reflection, Shadow};
-use deckcraft_model::{ColorRef, Effects, Fill, Geom, Line, ShapeStyle};
+use deckcraft_model::{ColorRef, Effects, Fill, Geom, Line, ShapeId, ShapeStyle};
 use serde_json::{Value, json};
 
 use super::{
@@ -556,81 +556,102 @@ fn edit_group_appearance(s: &mut Session, p: &Value, cmd: &str, f: impl Fn(&mut
     edit_shapes(s, p, cmd, |sh| apply(sh, 0, &f))
 }
 
-fn fill(s: &mut Session, p: &Value) -> Result<Value> {
-    let new_fill: Option<Option<Fill>> = if bool_or(p, "reset", false) {
-        Some(None)
-    } else if bool_or(p, "none", false) {
-        Some(Some(Fill::None))
-    } else if let Some(c) = color_param(p, "color") {
-        Some(Some(Fill::solid(c)))
-    } else if let Some(g) = p.get("gradient") {
-        Some(Some(Fill::Gradient(
-            gradient_param(g).ok_or_else(|| bad("shape.fill", "gradient needs at least two `stops`: [[0, \"#fff\"], [1, \"#000\"]]"))?,
-        )))
-    } else if let Some(pt) = p.get("pattern") {
-        Some(Some(Fill::Pattern(PatternFill {
+/// The fill a `shape.fill` request sets: `Some(None)` clears it, `Some(Some(_))` sets it, and `None`
+/// leaves it as it is.
+fn requested_fill(s: &mut Session, p: &Value) -> Result<Option<Option<Fill>>> {
+    if bool_or(p, "reset", false) {
+        return Ok(Some(None));
+    }
+    if bool_or(p, "none", false) {
+        return Ok(Some(Some(Fill::None)));
+    }
+    if let Some(c) = color_param(p, "color") {
+        return Ok(Some(Some(Fill::solid(c))));
+    }
+    if let Some(g) = p.get("gradient") {
+        let gradient = gradient_param(g).ok_or_else(|| bad("shape.fill", "gradient needs at least two `stops`: [[0, \"#fff\"], [1, \"#000\"]]"))?;
+        return Ok(Some(Some(Fill::Gradient(gradient))));
+    }
+    if let Some(pt) = p.get("pattern") {
+        return Ok(Some(Some(Fill::Pattern(PatternFill {
             preset: pt.get("preset").and_then(Value::as_str).unwrap_or("pct50").to_string(),
             fg: pt.get("fg").and_then(color_value).unwrap_or(ColorRef::scheme(SchemeSlot::Accent1)),
             bg: pt.get("bg").and_then(color_value).unwrap_or(ColorRef::scheme(SchemeSlot::Bg1)),
-        })))
-    } else if p.get("picture").is_some() {
+        }))));
+    }
+    if p.get("picture").is_some() {
         let (name, bytes) = super::insert::media_bytes(&with_param(p, "data", p.get("picture").cloned().unwrap_or_default()), "shape.fill")?;
         let ct = super::insert::content_type(&name, &bytes);
         let media = s.edit(|doc, _| doc.add_media(&name, ct, bytes).ok_or_else(|| bad("shape.fill", NO_ID_SPACE)))?;
-        Some(Some(Fill::Picture(PictureFill { media, ..Default::default() })))
-    } else {
-        None
-    };
+        return Ok(Some(Some(Fill::Picture(PictureFill { media, ..Default::default() }))));
+    }
+    Ok(None)
+}
+
+/// The effective fill of each targeted shape, for a transparency change on an inherited (style) fill.
+fn inherited_fills(s: &Session, p: &Value) -> Result<HashMap<ShapeId, Option<Fill>>> {
+    let st = s.doc()?;
+    let ctx = super::text::ctx_for(&st.doc, &st.selection);
+    let mut fills = HashMap::new();
+    for id in targets(s, p)? {
+        if let Some(sh) = st.shape(id) {
+            deckcraft_model::walk(std::slice::from_ref(sh), &mut |sh, _| {
+                let fill = ctx.as_ref().and_then(|c| {
+                    let (f, ph) = deckcraft_model::resolve::fill(c, sh);
+                    f.map(|f| match f {
+                        Fill::Solid { color } => Fill::solid(ColorRef::rgb(c.color(&color, ph))),
+                        other => other,
+                    })
+                });
+                fills.insert(sh.id, fill);
+            });
+        }
+    }
+    Ok(fills)
+}
+
+/// Applies a `shape.fill` request to one shape: the fill, then its picture options, then transparency.
+fn apply_fill(
+    sh: &mut deckcraft_model::Shape,
+    new_fill: Option<&Option<Fill>>,
+    pic_props: Option<&Value>,
+    transparency: Option<f64>,
+    inherited: &HashMap<ShapeId, Option<Fill>>,
+) -> Result<()> {
+    if let Some(f) = new_fill {
+        sh.fill.clone_from(f);
+    }
+    if let (Some(pp), Some(Fill::Picture(pf))) = (pic_props, sh.fill.as_mut()) {
+        picture_props(pf, pp);
+    }
+    if let (Some(t), Some(Fill::Picture(pf))) = (transparency, sh.fill.as_mut()) {
+        let a = 1.0 - t.clamp(0.0, 1.0);
+        pf.alpha = (a < 1.0).then_some(a);
+        return Ok(());
+    }
+    if let Some(t) = transparency {
+        let base = sh.fill.clone().or_else(|| inherited.get(&sh.id).cloned().flatten());
+        if let Some(Fill::Solid { mut color }) = base {
+            color.mods.retain(|m| !matches!(m, ColorTransform::Alpha(_)));
+            if t > 0.0 {
+                color.mods.push(ColorTransform::Alpha(((1.0 - t.clamp(0.0, 1.0)) * 100_000.0).round() as i32));
+            }
+            sh.fill = Some(Fill::Solid { color });
+        }
+    }
+    Ok(())
+}
+
+fn fill(s: &mut Session, p: &Value) -> Result<Value> {
+    let new_fill = requested_fill(s, p)?;
     let transparency = f64_param(p, "transparency");
     let pic_props = p.get("pictureProps").filter(|v| v.is_object());
     if new_fill.is_none() && transparency.is_none() && pic_props.is_none() {
         return Err(bad("shape.fill", "give `color`, `none`, `gradient`, `pattern`, `picture`, `pictureProps`, `transparency` or `reset`"));
     }
     // Transparency on an inherited (style) fill needs the effective colour.
-    let st = s.doc()?;
-    let ctx_fill = {
-        let ctx = super::text::ctx_for(&st.doc, &st.selection);
-        let mut fills = HashMap::new();
-        for id in targets(s, p)? {
-            if let Some(sh) = st.shape(id) {
-                deckcraft_model::walk(std::slice::from_ref(sh), &mut |sh, _| {
-                    let fill = ctx.as_ref().and_then(|c| {
-                        let (f, ph) = deckcraft_model::resolve::fill(c, sh);
-                        f.map(|f| match f {
-                            Fill::Solid { color } => Fill::solid(ColorRef::rgb(c.color(&color, ph))),
-                            other => other,
-                        })
-                    });
-                    fills.insert(sh.id, fill);
-                });
-            }
-        }
-        fills
-    };
-    edit_group_appearance(s, p, "shape.fill", |sh| {
-        if let Some(f) = &new_fill {
-            sh.fill.clone_from(f);
-        }
-        if let (Some(pp), Some(Fill::Picture(pf))) = (pic_props, sh.fill.as_mut()) {
-            picture_props(pf, pp);
-        }
-        if let (Some(t), Some(Fill::Picture(pf))) = (transparency, sh.fill.as_mut()) {
-            let a = 1.0 - t.clamp(0.0, 1.0);
-            pf.alpha = (a < 1.0).then_some(a);
-            return Ok(());
-        }
-        if let Some(t) = transparency {
-            let base = sh.fill.clone().or_else(|| ctx_fill.get(&sh.id).cloned().flatten());
-            if let Some(Fill::Solid { mut color }) = base {
-                color.mods.retain(|m| !matches!(m, ColorTransform::Alpha(_)));
-                if t > 0.0 {
-                    color.mods.push(ColorTransform::Alpha(((1.0 - t.clamp(0.0, 1.0)) * 100_000.0).round() as i32));
-                }
-                sh.fill = Some(Fill::Solid { color });
-            }
-        }
-        Ok(())
-    })
+    let inherited = inherited_fills(s, p)?;
+    edit_group_appearance(s, p, "shape.fill", |sh| apply_fill(sh, new_fill.as_ref(), pic_props, transparency, &inherited))
 }
 
 /// Applies Format Shape ▸ Picture or texture fill options to a picture fill.

crates/h264/src/dpb.rs

@@ -204,6 +204,48 @@ impl Dpb {
         entry_lists
     }
 
+    /// picNumLXNoWrap (8-34, 8-35) of a short-term modification from the predictor `pred`, and the
+    /// picNum it selects.
+    fn short_term_pic_nums(pred: i32, idc: u32, value: u32, curr_pic_num: i32, max_pic_num: i32) -> (i32, i32) {
+        let d = value as i32 + 1;
+        let no_wrap = if idc == 0 {
+            if pred - d < 0 { pred - d + max_pic_num } else { pred - d }
+        } else if pred + d >= max_pic_num {
+            pred + d - max_pic_num
+        } else {
+            pred + d
+        };
+        let pn = if no_wrap > curr_pic_num { no_wrap - max_pic_num } else { no_wrap };
+        (no_wrap, pn)
+    }
+
+    /// Puts `target` at `ref_idx` and shifts the rest of the list up, then drops the later entries
+    /// that repeat it (8.2.4.3.1, 8.2.4.3.2) and keeps the list `n` long.
+    fn insert_ref<'a>(list: &mut Vec<Option<&'a DpbEntry>>, ref_idx: usize, n: usize, target: &'a DpbEntry, is_long: bool) {
+        for c in (ref_idx + 1..=n).rev() {
+            list[c] = list[c - 1];
+        }
+        list[ref_idx] = Some(target);
+        let mut nidx = ref_idx + 1;
+        for c in ref_idx + 1..=n {
+            let keep = match list[c] {
+                None => true,
+                Some(e) => {
+                    if is_long {
+                        !(e.mark == RefMark::Long && e.long_term_frame_idx == target.long_term_frame_idx)
+                    } else {
+                        !(e.mark == RefMark::Short && std::ptr::eq(e, target))
+                    }
+                }
+            };
+            if keep {
+                list[nidx] = list[c];
+                nidx += 1;
+            }
+        }
+        list.truncate(n);
+    }
+
     /// Reference picture list modification (8.2.4.3) of one list; `n` is num_ref_idx_active.
     fn modify_ref_list<'a>(
         list: &mut Vec<Option<&'a DpbEntry>>,
@@ -223,16 +265,8 @@ impl Dpb {
             list.push(None); // temporarily one longer
             let (target, is_long): (Option<&DpbEntry>, bool) = match m.idc {
                 0 | 1 => {
-                    let d = m.value as i32 + 1;
-                    let no_wrap = if m.idc == 0 {
-                        if pred - d < 0 { pred - d + max_pic_num } else { pred - d }
-                    } else if pred + d >= max_pic_num {
-                        pred + d - max_pic_num
-                    } else {
-                        pred + d
-                    };
+                    let (no_wrap, pn) = Self::short_term_pic_nums(pred, m.idc, m.value, curr_pic_num, max_pic_num);
                     pred = no_wrap;
-                    let pn = if no_wrap > curr_pic_num { no_wrap - max_pic_num } else { no_wrap };
                     (short.iter().copied().find(|e| Self::frame_num_wrap(e, cur_fn, max_frame_num) == pn), false)
                 }
                 2 => (long.iter().copied().find(|e| e.long_term_frame_idx == m.value), true),
@@ -244,29 +278,8 @@ impl Dpb {
                 ref_idx += 1;
                 continue;
             };
-            for c in (ref_idx + 1..=n).rev() {
-                list[c] = list[c - 1];
-            }
-            list[ref_idx] = Some(target);
+            Self::insert_ref(list, ref_idx, n, target, is_long);
             ref_idx += 1;
-            let mut nidx = ref_idx;
-            for c in ref_idx..=n {
-                let keep = match list[c] {
-                    None => true,
-                    Some(e) => {
-                        if is_long {
-                            !(e.mark == RefMark::Long && e.long_term_frame_idx == target.long_term_frame_idx)
-                        } else {
-                            !(e.mark == RefMark::Short && std::ptr::eq(e, target))
-                        }
-                    }
-                };
-                if keep {
-                    list[nidx] = list[c];
-                    nidx += 1;
-                }
-            }
-            list.truncate(n);
         }
         Ok(())
     }

crates/hevc/src/slicedec.rs

@@ -277,6 +277,30 @@ pub struct SliceDecoder<'a> {
     pub ctb_y: i32,
 }
 
+/// Scaling process (8.6.3): dequantises the top-left `max_x` × `max_y` coefficients of the `n` × `n`
+/// block `coeffs` with scaling matrix `m` (flat when `None`).
+fn dequantize(coeffs: &mut [i32], n: usize, (max_x, max_y): (usize, usize), m: Option<&[u8]>, scale: i64, round: i64, bd_shift: u32) {
+    for y in 0..=max_y {
+        for x in 0..=max_x {
+            let v = coeffs[y * n + x];
+            if v != 0 {
+                let f = m.map_or(16, |m| m[y * n + x] as i64);
+                coeffs[y * n + x] = ((v as i64 * f * scale + round) >> bd_shift).clamp(-32768, 32767) as i32;
+            }
+        }
+    }
+}
+
+/// Adds the `n` × `n` residual `coeffs` to the samples of `plane` at (x0, y0), clipped to 0..=`max`.
+fn add_residual(plane: &mut [u16], stride: usize, (x0, y0): (usize, usize), n: usize, coeffs: &[i32], max: i32) {
+    for y in 0..n {
+        let row = &mut plane[(y0 + y) * stride + x0..][..n];
+        for (x, s) in row.iter_mut().enumerate() {
+            *s = (*s as i32 + coeffs[y * n + x]).clamp(0, max) as u16;
+        }
+    }
+}
+
 impl<'a> SliceDecoder<'a> {
     #[inline(always)]
     fn dd(&mut self, ctx: usize) -> u32 {
@@ -1331,15 +1355,7 @@ impl<'a> SliceDecoder<'a> {
                 }
                 _ => None,
             };
-            for y in 0..=max_y {
-                for x in 0..=max_x {
-                    let v = coeffs[y * n + x];
-                    if v != 0 {
-                        let f = m.map_or(16, |m| m[y * n + x] as i64);
-                        coeffs[y * n + x] = ((v as i64 * f * scale + round) >> bd_shift).clamp(-32768, 32767) as i32;
-                    }
-                }
-            }
+            dequantize(coeffs, n, (max_x, max_y), m, scale, round, bd_shift);
             let bd_shift = 20 - bd;
             if ts {
                 transform::transform_skip(coeffs, n, bd_shift);
@@ -1355,12 +1371,7 @@ impl<'a> SliceDecoder<'a> {
         let _ = dc_only;
         let (stride, max) = (if c == 0 { self.pic.width } else { self.pic.cwidth }, (1i32 << bd) - 1);
         let plane = &mut self.pic.planes[c];
-        for y in 0..n {
-            let row = &mut plane[(y0 as usize + y) * stride + x0 as usize..][..n];
-            for (x, s) in row.iter_mut().enumerate() {
-                *s = (*s as i32 + coeffs[y * n + x]).clamp(0, max) as u16;
-            }
-        }
+        add_residual(plane, stride, (x0 as usize, y0 as usize), n, coeffs, max);
         Ok(())
     }
 

crates/model/src/chart.rs

@@ -809,22 +809,15 @@ impl Chart {
 ///   near them.
 /// - All-negative values mirror this: the axis ends at zero when `hi` is above 5/6 of `lo`.
 ///   Mixed signs get headroom at both ends.
-pub fn axis_scale(
-    lo: f64,
-    hi: f64,
-    fmin: Option<f64>,
-    fmax: Option<f64>,
-    major: Option<f64>,
-    max_intervals: usize,
-    headroom: bool,
-) -> (f64, f64, f64) {
-    // Values past ±1e100 aren't axis values; clamping keeps the arithmetic finite.
-    let fin = |v: Option<f64>| v.filter(|v| v.is_finite()).map(|v| v.clamp(-1e100, 1e100));
-    let (fmin, fmax) = (fin(fmin), fin(fmax));
-    let (lo, hi) = if lo.is_finite() && hi.is_finite() { (lo.min(hi).clamp(-1e100, 1e100), lo.max(hi).clamp(-1e100, 1e100)) } else { (0.0, 1.0) };
-    // Office's automatic limits ("How chart axis limits are determined", as Jon Peltier
-    // summarises it): 5 % of the data range past the data, and zero when the values don't
-    // sit within the top sixth of their largest magnitude. A single value is measured from zero.
+/// The data range [lo, hi] an axis covers, clamped to ±1e100; (0, 1) without finite values.
+fn axis_data_range(lo: f64, hi: f64) -> (f64, f64) {
+    if lo.is_finite() && hi.is_finite() { (lo.min(hi).clamp(-1e100, 1e100), lo.max(hi).clamp(-1e100, 1e100)) } else { (0.0, 1.0) }
+}
+
+/// Office's automatic (min, max) of the data range [lo, hi]. "How chart axis limits are determined",
+/// as Jon Peltier summarises it: 5 % of the data range past the data, and zero when the values don't
+/// sit within the top sixth of their largest magnitude. A single value is measured from zero.
+fn auto_limits(lo: f64, hi: f64, headroom: bool) -> (f64, f64) {
     let flat = hi - lo <= 1e-12 * lo.abs().max(hi.abs());
     let pad = if !headroom {
         0.0
@@ -835,21 +828,23 @@ pub fn axis_scale(
     };
     let auto_lo = if lo >= 0.0 && (flat || lo < hi * 5.0 / 6.0) { 0.0 } else { lo - pad };
     let auto_hi = if hi <= 0.0 && (flat || hi > lo * 5.0 / 6.0) { 0.0 } else { hi + pad };
-    let mut lo = fmin.unwrap_or(auto_lo);
-    let mut hi = fmax.unwrap_or(auto_hi);
-    let mag = lo.abs().max(hi.abs());
-    // Relative to the data's magnitude, so tiny values don't count as flat; all-zero falls back to 1.
-    let unit = if mag == 0.0 { 1.0 } else { mag };
-    if hi - lo <= 1e-12 * mag {
-        // A fixed limit on the far side of the data: the automatic end gives way.
-        match (fmin, fmax) {
-            (None, Some(_)) => lo = if hi > 0.0 { 0.0 } else { hi - hi.abs().max(unit) },
-            (Some(_), None) if lo < 0.0 => hi = 0.0,
-            _ => hi = lo + unit,
-        }
+    (auto_lo, auto_hi)
+}
+
+/// The ends of a span too small to show: with one fixed limit on the far side of the data, the
+/// automatic end gives way; otherwise the span is one `unit` wide.
+fn flat_span_ends(fmin: Option<f64>, fmax: Option<f64>, lo: f64, hi: f64, unit: f64) -> (f64, f64) {
+    match (fmin, fmax) {
+        (None, Some(_)) => (if hi > 0.0 { 0.0 } else { hi - hi.abs().max(unit) }, hi),
+        (Some(_), None) if lo < 0.0 => (lo, 0.0),
+        _ => (lo, lo + unit),
     }
-    let n = max_intervals.clamp(1, 50) as f64;
-    let step = match fin(major).filter(|m| *m > 0.0 && (hi - lo) / m <= 1000.0) {
+}
+
+/// The major step: `major` when it gives at most 1000 intervals, else the smallest 1-2-5 step
+/// that fits `n` intervals over [lo, hi].
+fn axis_step(major: Option<f64>, lo: f64, hi: f64, n: f64, unit: f64) -> f64 {
+    match major.filter(|m| *m > 0.0 && (hi - lo) / m <= 1000.0) {
         Some(m) => m,
         None => {
             let mut step = 10f64.powf(((hi - lo) / n).log10().floor());
@@ -865,7 +860,32 @@ pub fn axis_scale(
             }
             step
         }
-    };
+    }
+}
+
+pub fn axis_scale(
+    lo: f64,
+    hi: f64,
+    fmin: Option<f64>,
+    fmax: Option<f64>,
+    major: Option<f64>,
+    max_intervals: usize,
+    headroom: bool,
+) -> (f64, f64, f64) {
+    // Values past ±1e100 aren't axis values; clamping keeps the arithmetic finite.
+    let fin = |v: Option<f64>| v.filter(|v| v.is_finite()).map(|v| v.clamp(-1e100, 1e100));
+    let (fmin, fmax) = (fin(fmin), fin(fmax));
+    let (lo, hi) = axis_data_range(lo, hi);
+    let (auto_lo, auto_hi) = auto_limits(lo, hi, headroom);
+    let (mut lo, mut hi) = (fmin.unwrap_or(auto_lo), fmax.unwrap_or(auto_hi));
+    let mag = lo.abs().max(hi.abs());
+    // Relative to the data's magnitude, so tiny values don't count as flat; all-zero falls back to 1.
+    let unit = if mag == 0.0 { 1.0 } else { mag };
+    if hi - lo <= 1e-12 * mag {
+        (lo, hi) = flat_span_ends(fmin, fmax, lo, hi, unit);
+    }
+    let n = max_intervals.clamp(1, 50) as f64;
+    let step = axis_step(fin(major), lo, hi, n, unit);
     let min = fmin.unwrap_or((lo / step + 1e-9).floor() * step);
     let max = fmax.unwrap_or((hi / step - 1e-9).ceil() * step).max(min + step);
     (min, max, step)

crates/pptx/src/read/dml.rs

@@ -576,6 +576,44 @@ pub fn text_body(imp: &mut Imp, part: &Part, tx: &El) -> TextBody {
 
 const MAX_PARAGRAPH_RUNS: usize = 10_000;
 
+/// The run properties of `e`'s `rPr` child, or the defaults.
+fn run_props(imp: &mut Imp, part: &Part, e: &El) -> RunProps {
+    e.child("rPr").map(|r| rpr(imp, part, r)).unwrap_or_default()
+}
+
+/// Appends the runs of an `a:r` text, where a vertical tab or line feed is a line break, as it
+/// lays out and as export writes it.
+fn push_text_runs(para: &mut Paragraph, props: RunProps, text: &str) {
+    for (i, piece) in text.split(['\u{b}', '\n']).enumerate() {
+        if para.runs.len() >= MAX_PARAGRAPH_RUNS {
+            break;
+        }
+        if i > 0 {
+            para.runs.push(Run { text: String::new(), props: props.clone(), kind: RunKind::Break });
+        }
+        if !piece.is_empty() {
+            if para.runs.len() >= MAX_PARAGRAPH_RUNS {
+                break;
+            }
+            para.runs.push(Run { text: piece.to_string(), props: props.clone(), kind: RunKind::Text });
+        }
+    }
+}
+
+/// Appends an Office Math (a14:m) run: its plain text and its OMML.
+fn push_math_run(para: &mut Paragraph, part: &Part, e: &El) {
+    if para.runs.len() < MAX_PARAGRAPH_RUNS {
+        let mut text = String::new();
+        let mut ts = vec![];
+        e.find_all("t", &mut ts);
+        for t in ts {
+            text.push_str(&t.text());
+        }
+        let omml = e.elements().map(|c| part.keep_inner(c)).collect::<String>();
+        para.runs.push(Run { text, props: RunProps::default(), kind: RunKind::Math { omml } });
+    }
+}
+
 pub fn paragraph(imp: &mut Imp, part: &Part, p: &El) -> Paragraph {
     let mut para = Paragraph::default();
     for e in p.elements() {
@@ -589,50 +627,24 @@ pub fn paragraph(imp: &mut Imp, part: &Part, p: &El) -> Paragraph {
                 }
             }
             "r" => {
-                let props = e.child("rPr").map(|r| rpr(imp, part, r)).unwrap_or_default();
+                let props = run_props(imp, part, e);
                 let text: String = e.child("t").map(|t| t.text()).unwrap_or_default();
-                // A vertical tab or line feed inside text is a line break, as it lays out and as export writes it.
-                for (i, piece) in text.split(['\u{b}', '\n']).enumerate() {
-                    if para.runs.len() >= MAX_PARAGRAPH_RUNS {
-                        break;
-                    }
-                    if i > 0 {
-                        para.runs.push(Run { text: String::new(), props: props.clone(), kind: RunKind::Break });
-                    }
-                    if !piece.is_empty() {
-                        if para.runs.len() >= MAX_PARAGRAPH_RUNS {
-                            break;
-                        }
-                        para.runs.push(Run { text: piece.to_string(), props: props.clone(), kind: RunKind::Text });
-                    }
-                }
+                push_text_runs(&mut para, props, &text);
             }
             "br" => {
                 if para.runs.len() < MAX_PARAGRAPH_RUNS {
-                    let props = e.child("rPr").map(|r| rpr(imp, part, r)).unwrap_or_default();
+                    let props = run_props(imp, part, e);
                     para.runs.push(Run { text: String::new(), props, kind: RunKind::Break });
                 }
             }
             "fld" => {
                 if para.runs.len() < MAX_PARAGRAPH_RUNS {
-                    let props = e.child("rPr").map(|r| rpr(imp, part, r)).unwrap_or_default();
+                    let props = run_props(imp, part, e);
                     let text = e.child("t").map(|t| t.text()).unwrap_or_default();
                     para.runs.push(Run { text, props, kind: RunKind::Field { field: e.attr("type").unwrap_or("").to_string() } });
                 }
             }
-            "m" => {
-                if para.runs.len() < MAX_PARAGRAPH_RUNS {
-                    // Office Math (a14:m) — keep the OMML and its plain text.
-                    let mut text = String::new();
-                    let mut ts = vec![];
-                    e.find_all("t", &mut ts);
-                    for t in ts {
-                        text.push_str(&t.text());
-                    }
-                    let omml = e.elements().map(|c| part.keep_inner(c)).collect::<String>();
-                    para.runs.push(Run { text, props: RunProps::default(), kind: RunKind::Math { omml } });
-                }
-            }
+            "m" => push_math_run(&mut para, part, e),
             "endParaRPr" => para.end_props = rpr(imp, part, e),
             _ => {}
         }